# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-2010 Tiny SPRL (<http://tiny.be>).
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

import time
from lxml import etree

from openerp.osv import fields, osv
import openerp.addons.decimal_precision as dp
from openerp.tools.translate import _
from openerp.tools import float_compare
from openerp.report import report_sxw
import openerp

class res_currency(osv.osv):
    _inherit = "res.currency"

    def _get_current_rate(self, cr, uid, ids, raise_on_no_rate=True, context=None):
        if context is None:
            context = {}
        res = super(res_currency, self)._get_current_rate(cr, uid, ids, raise_on_no_rate, context=context)
        if context.get('voucher_special_currency') in ids and context.get('voucher_special_currency_rate'):
            res[context.get('voucher_special_currency')] = context.get('voucher_special_currency_rate')
        return res


class account_voucher(osv.osv):
    def _check_paid(self, cr, uid, ids, name, args, context=None):
        res = {}
        for voucher in self.browse(cr, uid, ids, context=context):
            res[voucher.id] = any([((line.account_id.type, 'in', ('receivable', 'payable')) and line.reconcile_id) for line in voucher.move_ids])
        return res

    def _get_type(self, cr, uid, context=None):
        if context is None:
            context = {}
        return context.get('type', False)

    def _get_period(self, cr, uid, context=None):
        if context is None: context = {}
        if context.get('period_id', False):
            return context.get('period_id')
        periods = self.pool.get('account.period').find(cr, uid, context=context)
        return periods and periods[0] or False

    def _make_journal_search(self, cr, uid, ttype, context=None):
        journal_pool = self.pool.get('account.journal')
        return journal_pool.search(cr, uid, [('type', '=', ttype)], limit=1)

    def _get_journal(self, cr, uid, context=None):
        if context is None: context = {}
        invoice_pool = self.pool.get('account.invoice')
        journal_pool = self.pool.get('account.journal')
        if context.get('invoice_id', False):
            invoice = invoice_pool.browse(cr, uid, context['invoice_id'], context=context)
            journal_id = journal_pool.search(cr, uid, [
                ('currency', '=', invoice.currency_id.id), ('company_id', '=', invoice.company_id.id)
            ], limit=1, context=context)
            return journal_id and journal_id[0] or False
        if context.get('journal_id', False):
            return context.get('journal_id')
        if not context.get('journal_id', False) and context.get('search_default_journal_id', False):
            return context.get('search_default_journal_id')

        ttype = context.get('type', 'bank')
        if ttype in ('payment', 'receipt'):
            ttype = 'bank'
        res = self._make_journal_search(cr, uid, ttype, context=context)
        return res and res[0] or False

    def _get_tax(self, cr, uid, context=None):
        if context is None: context = {}
        journal_pool = self.pool.get('account.journal')
        journal_id = context.get('journal_id', False)
        if not journal_id:
            ttype = context.get('type', 'bank')
            res = journal_pool.search(cr, uid, [('type', '=', ttype)], limit=1)
            if not res:
                return False
            journal_id = res[0]

        if not journal_id:
            return False
        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        account_id = journal.default_credit_account_id or journal.default_debit_account_id
        if account_id and account_id.tax_ids:
            tax_id = account_id.tax_ids[0].id
            return tax_id
        return False

    def _get_payment_rate_currency(self, cr, uid, context=None):
        """
        Return the default value for field payment_rate_currency_id: the currency of the journal
        if there is one, otherwise the currency of the user's company
        """
        if context is None: context = {}
        journal_pool = self.pool.get('account.journal')
        journal_id = context.get('journal_id', False)
        if journal_id:
            journal = journal_pool.browse(cr, uid, journal_id, context=context)
            if journal.currency:
                return journal.currency.id
        #no journal given in the context, use company currency as default
        return self.pool.get('res.users').browse(cr, uid, uid, context=context).company_id.currency_id.id

    def _get_currency(self, cr, uid, context=None):
        if context is None: context = {}
        journal_pool = self.pool.get('account.journal')
        journal_id = context.get('journal_id', False)
        if journal_id:
            if isinstance(journal_id, (list, tuple)):
                # sometimes journal_id is a pair (id, display_name)
                journal_id = journal_id[0]
            journal = journal_pool.browse(cr, uid, journal_id, context=context)
            if journal.currency:
                return journal.currency.id
        return self.pool.get('res.users').browse(cr, uid, uid, context=context).company_id.currency_id.id

    def _get_partner(self, cr, uid, context=None):
        if context is None: context = {}
        return context.get('partner_id', False)

    def _get_reference(self, cr, uid, context=None):
        if context is None: context = {}
        return context.get('reference', False)

    def _get_narration(self, cr, uid, context=None):
        if context is None: context = {}
        return context.get('narration', False)

    def _get_amount(self, cr, uid, context=None):
        if context is None:
            context= {}
        return context.get('amount', 0.0)

    def name_get(self, cr, uid, ids, context=None):
        if not ids:
            return []
        if context is None: context = {}
        return [(r['id'], (r['number'] or _('Voucher'))) for r in self.read(cr, uid, ids, ['number'], context, load='_classic_write')]

    def fields_view_get(self, cr, uid, view_id=None, view_type=False, context=None, toolbar=False, submenu=False):
        mod_obj = self.pool.get('ir.model.data')
        if context is None: context = {}

        if view_type == 'form':
            if not view_id and context.get('invoice_type'):
                if context.get('invoice_type') in ('out_invoice', 'out_refund'):
                    result = mod_obj.get_object_reference(cr, uid, 'account_voucher', 'view_vendor_receipt_form')
                else:
                    result = mod_obj.get_object_reference(cr, uid, 'account_voucher', 'view_vendor_payment_form')
                result = result and result[1] or False
                view_id = result
            if not view_id and context.get('line_type'):
                if context.get('line_type') == 'customer':
                    result = mod_obj.get_object_reference(cr, uid, 'account_voucher', 'view_vendor_receipt_form')
                else:
                    result = mod_obj.get_object_reference(cr, uid, 'account_voucher', 'view_vendor_payment_form')
                result = result and result[1] or False
                view_id = result

        res = super(account_voucher, self).fields_view_get(cr, uid, view_id=view_id, view_type=view_type, context=context, toolbar=toolbar, submenu=submenu)
        doc = etree.XML(res['arch'])

        if context.get('type', 'sale') in ('purchase', 'payment'):
            nodes = doc.xpath("//field[@name='partner_id']")
            for node in nodes:
                node.set('context', "{'default_customer': 0, 'search_default_supplier': 1, 'default_supplier': 1}")
                if context.get('invoice_type','') in ('in_invoice', 'in_refund'):
                    node.set('string', _("Supplier"))
        res['arch'] = etree.tostring(doc)
        return res

    def _compute_writeoff_amount(self, cr, uid, line_dr_ids, line_cr_ids, amount, type):
        debit = credit = 0.0
        sign = type == 'payment' and -1 or 1
        for l in line_dr_ids:
            if isinstance(l, dict):
                debit += l['amount']
        for l in line_cr_ids:
            if isinstance(l, dict):
                credit += l['amount']
        return amount - sign * (credit - debit)

    def onchange_line_ids(self, cr, uid, ids, line_dr_ids, line_cr_ids, amount, voucher_currency, type, context=None):
        context = context or {}
        if not line_dr_ids and not line_cr_ids:
            return {'value':{'writeoff_amount': 0.0}}
        # resolve lists of commands into lists of dicts
        line_dr_ids = self.resolve_2many_commands(cr, uid, 'line_dr_ids', line_dr_ids, ['amount'], context)
        line_cr_ids = self.resolve_2many_commands(cr, uid, 'line_cr_ids', line_cr_ids, ['amount'], context)
        #compute the field is_multi_currency that is used to hide/display options linked to secondary currency on the voucher
        is_multi_currency = False
        #loop on the voucher lines to see if one of these has a secondary currency. If yes, we need to see the options
        for voucher_line in line_dr_ids+line_cr_ids:
            line_id = voucher_line.get('id') and self.pool.get('account.voucher.line').browse(cr, uid, voucher_line['id'], context=context).move_line_id.id or voucher_line.get('move_line_id')
            if line_id and self.pool.get('account.move.line').browse(cr, uid, line_id, context=context).currency_id:
                is_multi_currency = True
                break
        return {'value': {'writeoff_amount': self._compute_writeoff_amount(cr, uid, line_dr_ids, line_cr_ids, amount, type), 'is_multi_currency': is_multi_currency}}

    def _get_journal_currency(self, cr, uid, ids, name, args, context=None):
        res = {}
        for voucher in self.browse(cr, uid, ids, context=context):
            res[voucher.id] = voucher.journal_id.currency and voucher.journal_id.currency.id or voucher.company_id.currency_id.id
        return res

    def _get_writeoff_amount(self, cr, uid, ids, name, args, context=None):
        if not ids: return {}
        currency_obj = self.pool.get('res.currency')
        res = {}
        for voucher in self.browse(cr, uid, ids, context=context):
            debit = credit = 0.0
            sign = voucher.type == 'payment' and -1 or 1
            for l in voucher.line_dr_ids:
                debit += l.amount
            for l in voucher.line_cr_ids:
                credit += l.amount
            currency = voucher.currency_id or voucher.company_id.currency_id
            res[voucher.id] =  currency_obj.round(cr, uid, currency, voucher.amount - sign * (credit - debit))
        return res

    def _paid_amount_in_company_currency(self, cr, uid, ids, name, args, context=None):
        if context is None:
            context = {}
        res = {}
        ctx = context.copy()
        for v in self.browse(cr, uid, ids, context=context):
            ctx.update({'date': v.date})
            #make a new call to browse in order to have the right date in the context, to get the right currency rate
            voucher = self.browse(cr, uid, v.id, context=ctx)
            ctx.update({
              'voucher_special_currency': voucher.payment_rate_currency_id and voucher.payment_rate_currency_id.id or False,
              'voucher_special_currency_rate': voucher.currency_id.rate * voucher.payment_rate,})
            res[voucher.id] =  self.pool.get('res.currency').compute(cr, uid, voucher.currency_id.id, voucher.company_id.currency_id.id, voucher.amount, context=ctx)
        return res

    def _get_currency_help_label(self, cr, uid, currency_id, payment_rate, payment_rate_currency_id, context=None):
        """
        This function builds a string to help the users to understand the behavior of the payment rate fields they can specify on the voucher. 
        This string is only used to improve the usability in the voucher form view and has no other effect.

        :param currency_id: the voucher currency
        :type currency_id: integer
        :param payment_rate: the value of the payment_rate field of the voucher
        :type payment_rate: float
        :param payment_rate_currency_id: the value of the payment_rate_currency_id field of the voucher
        :type payment_rate_currency_id: integer
        :return: translated string giving a tip on what's the effect of the current payment rate specified
        :rtype: str
        """
        rml_parser = report_sxw.rml_parse(cr, uid, 'currency_help_label', context=context)
        currency_pool = self.pool.get('res.currency')
        currency_str = payment_rate_str = ''
        if currency_id:
            currency_str = rml_parser.formatLang(1, currency_obj=currency_pool.browse(cr, uid, currency_id, context=context))
        if payment_rate_currency_id:
            payment_rate_str  = rml_parser.formatLang(payment_rate, currency_obj=currency_pool.browse(cr, uid, payment_rate_currency_id, context=context))
        currency_help_label = _('At the operation date, the exchange rate was\n%s = %s') % (currency_str, payment_rate_str)
        return currency_help_label

    def _fnct_currency_help_label(self, cr, uid, ids, name, args, context=None):
        res = {}
        for voucher in self.browse(cr, uid, ids, context=context):
            res[voucher.id] = self._get_currency_help_label(cr, uid, voucher.currency_id.id, voucher.payment_rate, voucher.payment_rate_currency_id.id, context=context)
        return res

    _name = 'account.voucher'
    _description = 'Accounting Voucher'
    _inherit = ['mail.thread']
    _order = "date desc, id desc"
#    _rec_name = 'number'
    _track = {
        'state': {
            'account_voucher.mt_voucher_state_change': lambda self, cr, uid, obj, ctx=None: True,
        },
    }

    _columns = {
        'type':fields.selection([
            ('sale','Sale'),
            ('purchase','Purchase'),
            ('payment','Payment'),
            ('receipt','Receipt'),
        ],'Default Type', readonly=True, states={'draft':[('readonly',False)]}),
        'name':fields.char('Memo', readonly=True, states={'draft':[('readonly',False)]}),
        'date':fields.date('Date', readonly=True, select=True, states={'draft':[('readonly',False)]},
                           help="Effective date for accounting entries", copy=False),
        'journal_id':fields.many2one('account.journal', 'Journal', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'account_id':fields.many2one('account.account', 'Account', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'line_ids':fields.one2many('account.voucher.line', 'voucher_id', 'Voucher Lines',
                                   readonly=True, copy=True,
                                   states={'draft':[('readonly',False)]}),
        'line_cr_ids':fields.one2many('account.voucher.line','voucher_id','Credits',
            domain=[('type','=','cr')], context={'default_type':'cr'}, readonly=True, states={'draft':[('readonly',False)]}),
        'line_dr_ids':fields.one2many('account.voucher.line','voucher_id','Debits',
            domain=[('type','=','dr')], context={'default_type':'dr'}, readonly=True, states={'draft':[('readonly',False)]}),
        'period_id': fields.many2one('account.period', 'Period', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'narration':fields.text('Notes', readonly=True, states={'draft':[('readonly',False)]}),
        'currency_id': fields.function(_get_journal_currency, type='many2one', relation='res.currency', string='Currency', readonly=True, required=True),
        'company_id': fields.many2one('res.company', 'Company', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'state':fields.selection(
            [('draft','Draft'),
             ('cancel','Cancelled'),
             ('proforma','Pro-forma'),
             ('posted','Posted')
            ], 'Status', readonly=True, track_visibility='onchange', copy=False,
            help=' * The \'Draft\' status is used when a user is encoding a new and unconfirmed Voucher. \
                        \n* The \'Pro-forma\' when voucher is in Pro-forma status,voucher does not have an voucher number. \
                        \n* The \'Posted\' status is used when user create voucher,a voucher number is generated and voucher entries are created in account \
                        \n* The \'Cancelled\' status is used when user cancel voucher.'),
        'amount': fields.float('Total', digits_compute=dp.get_precision('Account'), required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'tax_amount':fields.float('Tax Amount', digits_compute=dp.get_precision('Account'), readonly=True),
        'reference': fields.char('Ref #', readonly=True, states={'draft':[('readonly',False)]},
                                 help="Transaction reference number.", copy=False),
        'number': fields.char('Number', readonly=True, copy=False),
        'move_id':fields.many2one('account.move', 'Account Entry', copy=False),
        'move_ids': fields.related('move_id','line_id', type='one2many', relation='account.move.line', string='Journal Items', readonly=True),
        'partner_id':fields.many2one('res.partner', 'Partner', change_default=1, readonly=True, states={'draft':[('readonly',False)]}),
        'audit': fields.related('move_id','to_check', type='boolean', help='Check this box if you are unsure of that journal entry and if you want to note it as \'to be reviewed\' by an accounting expert.', relation='account.move', string='To Review'),
        'paid': fields.function(_check_paid, string='Paid', type='boolean', help="The Voucher has been totally paid."),
        'pay_now':fields.selection([
            ('pay_now','Pay Directly'),
            ('pay_later','Pay Later or Group Funds'),
        ],'Payment', select=True, readonly=True, states={'draft':[('readonly',False)]}),
        'tax_id': fields.many2one('account.tax', 'Tax', readonly=True, states={'draft':[('readonly',False)]}, domain=[('price_include','=', False)], help="Only for tax excluded from price"),
        'pre_line':fields.boolean('Previous Payments ?', required=False),
        'date_due': fields.date('Due Date', readonly=True, select=True, states={'draft':[('readonly',False)]}),
        'payment_option':fields.selection([
                                           ('without_writeoff', 'Keep Open'),
                                           ('with_writeoff', 'Reconcile Payment Balance'),
                                           ], 'Payment Difference', required=True, readonly=True, states={'draft': [('readonly', False)]}, help="This field helps you to choose what you want to do with the eventual difference between the paid amount and the sum of allocated amounts. You can either choose to keep open this difference on the partner's account, or reconcile it with the payment(s)"),
        'writeoff_acc_id': fields.many2one('account.account', 'Counterpart Account', readonly=True, states={'draft': [('readonly', False)]}),
        'comment': fields.char('Counterpart Comment', required=True, readonly=True, states={'draft': [('readonly', False)]}),
        'analytic_id': fields.many2one('account.analytic.account','Write-Off Analytic Account', readonly=True, states={'draft': [('readonly', False)]}),
        'writeoff_amount': fields.function(_get_writeoff_amount, string='Difference Amount', type='float', readonly=True, help="Computed as the difference between the amount stated in the voucher and the sum of allocation on the voucher lines."),
        'payment_rate_currency_id': fields.many2one('res.currency', 'Payment Rate Currency', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'payment_rate': fields.float('Exchange Rate', digits=(12,6), required=True, readonly=True, states={'draft': [('readonly', False)]},
            help='The specific rate that will be used, in this voucher, between the selected currency (in \'Payment Rate Currency\' field)  and the voucher currency.'),
        'paid_amount_in_company_currency': fields.function(_paid_amount_in_company_currency, string='Paid Amount in Company Currency', type='float', readonly=True),
        'is_multi_currency': fields.boolean('Multi Currency Voucher', help='Fields with internal purpose only that depicts if the voucher is a multi currency one or not'),
        'currency_help_label': fields.function(_fnct_currency_help_label, type='text', string="Helping Sentence", help="This sentence helps you to know how to specify the payment rate by giving you the direct effect it has"), 
    }
    _defaults = {
        'period_id': _get_period,
        'partner_id': _get_partner,
        'journal_id':_get_journal,
        'currency_id': _get_currency,
        'reference': _get_reference,
        'narration':_get_narration,
        'amount': _get_amount,
        'type':_get_type,
        'state': 'draft',
        'pay_now': 'pay_now',
        'name': '',
        'date': fields.date.context_today,
        'company_id': lambda self,cr,uid,c: self.pool.get('res.company')._company_default_get(cr, uid, 'account.voucher',context=c),
        'tax_id': _get_tax,
        'payment_option': 'without_writeoff',
        'comment': _('Write-Off'),
        'payment_rate': 1.0,
        'payment_rate_currency_id': _get_payment_rate_currency,
    }

    def compute_tax(self, cr, uid, ids, context=None):
        tax_pool = self.pool.get('account.tax')
        partner_pool = self.pool.get('res.partner')
        position_pool = self.pool.get('account.fiscal.position')
        voucher_line_pool = self.pool.get('account.voucher.line')
        voucher_pool = self.pool.get('account.voucher')
        if context is None: context = {}

        for voucher in voucher_pool.browse(cr, uid, ids, context=context):
            voucher_amount = 0.0
            for line in voucher.line_ids:
                voucher_amount += line.untax_amount or line.amount
                line.amount = line.untax_amount or line.amount
                voucher_line_pool.write(cr, uid, [line.id], {'amount':line.amount, 'untax_amount':line.untax_amount})

            if not voucher.tax_id:
                self.write(cr, uid, [voucher.id], {'amount':voucher_amount, 'tax_amount':0.0})
                continue

            tax = [tax_pool.browse(cr, uid, voucher.tax_id.id, context=context)]
            partner = partner_pool.browse(cr, uid, voucher.partner_id.id, context=context) or False
            taxes = position_pool.map_tax(cr, uid, partner and partner.property_account_position or False, tax)
            tax = tax_pool.browse(cr, uid, taxes, context=context)

            total = voucher_amount
            total_tax = 0.0

            if not tax[0].price_include:
                for line in voucher.line_ids:
                    for tax_line in tax_pool.compute_all(cr, uid, tax, line.amount, 1).get('taxes', []):
                        total_tax += tax_line.get('amount', 0.0)
                total += total_tax
            else:
                for line in voucher.line_ids:
                    line_total = 0.0
                    line_tax = 0.0

                    for tax_line in tax_pool.compute_all(cr, uid, tax, line.untax_amount or line.amount, 1).get('taxes', []):
                        line_tax += tax_line.get('amount', 0.0)
                        line_total += tax_line.get('price_unit')
                    total_tax += line_tax
                    untax_amount = line.untax_amount or line.amount
                    voucher_line_pool.write(cr, uid, [line.id], {'amount':line_total, 'untax_amount':untax_amount})

            self.write(cr, uid, [voucher.id], {'amount':total, 'tax_amount':total_tax})
        return True

    def onchange_price(self, cr, uid, ids, line_ids, tax_id, partner_id=False, context=None):
        context = context or {}
        tax_pool = self.pool.get('account.tax')
        partner_pool = self.pool.get('res.partner')
        position_pool = self.pool.get('account.fiscal.position')
        if not line_ids:
            line_ids = []
        res = {
            'tax_amount': False,
            'amount': False,
        }
        voucher_total = 0.0

        # resolve the list of commands into a list of dicts
        line_ids = self.resolve_2many_commands(cr, uid, 'line_ids', line_ids, ['amount'], context)

        total_tax = 0.0
        for line in line_ids:
            line_amount = 0.0
            line_amount = line.get('amount',0.0)

            if tax_id:
                tax = [tax_pool.browse(cr, uid, tax_id, context=context)]
                if partner_id:
                    partner = partner_pool.browse(cr, uid, partner_id, context=context) or False
                    taxes = position_pool.map_tax(cr, uid, partner and partner.property_account_position or False, tax)
                    tax = tax_pool.browse(cr, uid, taxes, context=context)

                if not tax[0].price_include:
                    for tax_line in tax_pool.compute_all(cr, uid, tax, line_amount, 1).get('taxes', []):
                        total_tax += tax_line.get('amount')

            voucher_total += line_amount
        total = voucher_total + total_tax

        res.update({
            'amount': total or voucher_total,
            'tax_amount': total_tax
        })
        return {
            'value': res
        }

    def onchange_term_id(self, cr, uid, ids, term_id, amount):
        term_pool = self.pool.get('account.payment.term')
        terms = False
        due_date = False
        default = {'date_due':False}
        if term_id and amount:
            terms = term_pool.compute(cr, uid, term_id, amount)
        if terms:
            due_date = terms[-1][0]
            default.update({
                'date_due':due_date
            })
        return {'value':default}

    def onchange_journal_voucher(self, cr, uid, ids, line_ids=False, tax_id=False, price=0.0, partner_id=False, journal_id=False, ttype=False, company_id=False, context=None):
        """price
        Returns a dict that contains new values and context

        @param partner_id: latest value from user input for field partner_id
        @param args: other arguments
        @param context: context arguments, like lang, time zone

        @return: Returns a dict which contains new values, and context
        """
        default = {
            'value':{},
        }

        if not partner_id or not journal_id:
            return default

        partner_pool = self.pool.get('res.partner')
        journal_pool = self.pool.get('account.journal')

        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        partner = partner_pool.browse(cr, uid, partner_id, context=context)
        account_id = False
        tr_type = False
        if journal.type in ('sale','sale_refund'):
            account_id = partner.property_account_receivable.id
            tr_type = 'sale'
        elif journal.type in ('purchase', 'purchase_refund','expense'):
            account_id = partner.property_account_payable.id
            tr_type = 'purchase'
        else:
            if not journal.default_credit_account_id or not journal.default_debit_account_id:
                raise osv.except_osv(_('Error!'), _('Please define default credit/debit accounts on the journal "%s".') % (journal.name))
            if ttype in ('sale', 'receipt'):
                account_id = journal.default_debit_account_id.id
            elif ttype in ('purchase', 'payment'):
                account_id = journal.default_credit_account_id.id
            else:
                account_id = journal.default_credit_account_id.id or journal.default_debit_account_id.id
            tr_type = 'receipt'

        default['value']['account_id'] = account_id
        default['value']['type'] = ttype or tr_type

        vals = self.onchange_journal(cr, uid, ids, journal_id, line_ids, tax_id, partner_id, time.strftime('%Y-%m-%d'), price, ttype, company_id, context)
        default['value'].update(vals.get('value'))

        return default

    def onchange_rate(self, cr, uid, ids, rate, amount, currency_id, payment_rate_currency_id, company_id, context=None):
        res =  {'value': {'paid_amount_in_company_currency': amount, 'currency_help_label': self._get_currency_help_label(cr, uid, currency_id, rate, payment_rate_currency_id, context=context)}}
        if rate and amount and currency_id:
            company_currency = self.pool.get('res.company').browse(cr, uid, company_id, context=context).currency_id
            #context should contain the date, the payment currency and the payment rate specified on the voucher
            amount_in_company_currency = self.pool.get('res.currency').compute(cr, uid, currency_id, company_currency.id, amount, context=context)
            res['value']['paid_amount_in_company_currency'] = amount_in_company_currency
        return res

    def onchange_amount(self, cr, uid, ids, amount, rate, partner_id, journal_id, currency_id, ttype, date, payment_rate_currency_id, company_id, context=None):
        if context is None:
            context = {}
        ctx = context.copy()
        ctx.update({'date': date})
        #read the voucher rate with the right date in the context
        currency_id = currency_id or self.pool.get('res.company').browse(cr, uid, company_id, context=ctx).currency_id.id
        voucher_rate = self.pool.get('res.currency').read(cr, uid, [currency_id], ['rate'], context=ctx)[0]['rate']
        ctx.update({
            'voucher_special_currency': payment_rate_currency_id,
            'voucher_special_currency_rate': rate * voucher_rate})
        res = self.recompute_voucher_lines(cr, uid, ids, partner_id, journal_id, amount, currency_id, ttype, date, context=ctx)
        vals = self.onchange_rate(cr, uid, ids, rate, amount, currency_id, payment_rate_currency_id, company_id, context=ctx)
        for key in vals.keys():
            res[key].update(vals[key])
        return res

    def recompute_payment_rate(self, cr, uid, ids, vals, currency_id, date, ttype, journal_id, amount, context=None):
        if context is None:
            context = {}
        #on change of the journal, we need to set also the default value for payment_rate and payment_rate_currency_id
        currency_obj = self.pool.get('res.currency')
        journal = self.pool.get('account.journal').browse(cr, uid, journal_id, context=context)
        company_id = journal.company_id.id
        payment_rate = 1.0
        currency_id = currency_id or journal.company_id.currency_id.id
        payment_rate_currency_id = currency_id
        ctx = context.copy()
        ctx.update({'date': date})
        o2m_to_loop = False
        if ttype == 'receipt':
            o2m_to_loop = 'line_cr_ids'
        elif ttype == 'payment':
            o2m_to_loop = 'line_dr_ids'
        if o2m_to_loop and 'value' in vals and o2m_to_loop in vals['value']:
            for voucher_line in vals['value'][o2m_to_loop]:
                if not isinstance(voucher_line, dict):
                    continue
                if voucher_line['currency_id'] != currency_id:
                    # we take as default value for the payment_rate_currency_id, the currency of the first invoice that
                    # is not in the voucher currency
                    payment_rate_currency_id = voucher_line['currency_id']
                    tmp = currency_obj.browse(cr, uid, payment_rate_currency_id, context=ctx).rate
                    payment_rate = tmp / currency_obj.browse(cr, uid, currency_id, context=ctx).rate
                    break
        vals['value'].update({
            'payment_rate': payment_rate,
            'currency_id': currency_id,
            'payment_rate_currency_id': payment_rate_currency_id
        })
        #read the voucher rate with the right date in the context
        voucher_rate = self.pool.get('res.currency').read(cr, uid, [currency_id], ['rate'], context=ctx)[0]['rate']
        ctx.update({
            'voucher_special_currency_rate': payment_rate * voucher_rate,
            'voucher_special_currency': payment_rate_currency_id})
        res = self.onchange_rate(cr, uid, ids, payment_rate, amount, currency_id, payment_rate_currency_id, company_id, context=ctx)
        for key in res.keys():
            vals[key].update(res[key])
        return vals

    def basic_onchange_partner(self, cr, uid, ids, partner_id, journal_id, ttype, context=None):
        partner_pool = self.pool.get('res.partner')
        journal_pool = self.pool.get('account.journal')
        res = {'value': {'account_id': False}}
        if not partner_id or not journal_id:
            return res

        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        partner = partner_pool.browse(cr, uid, partner_id, context=context)
        account_id = False
        if journal.type in ('sale','sale_refund'):
            account_id = partner.property_account_receivable.id
        elif journal.type in ('purchase', 'purchase_refund','expense'):
            account_id = partner.property_account_payable.id
        elif ttype in ('sale', 'receipt'):
            account_id = journal.default_debit_account_id.id
        elif ttype in ('purchase', 'payment'):
            account_id = journal.default_credit_account_id.id
        else:
            account_id = journal.default_credit_account_id.id or journal.default_debit_account_id.id

        res['value']['account_id'] = account_id
        return res

    def onchange_partner_id(self, cr, uid, ids, partner_id, journal_id, amount, currency_id, ttype, date, context=None):
        if not journal_id:
            return {}
        if context is None:
            context = {}
        #TODO: comment me and use me directly in the sales/purchases views
        res = self.basic_onchange_partner(cr, uid, ids, partner_id, journal_id, ttype, context=context)
        if ttype in ['sale', 'purchase']:
            return res
        ctx = context.copy()
        # not passing the payment_rate currency and the payment_rate in the context but it's ok because they are reset in recompute_payment_rate
        ctx.update({'date': date})
        vals = self.recompute_voucher_lines(cr, uid, ids, partner_id, journal_id, amount, currency_id, ttype, date, context=ctx)
        vals2 = self.recompute_payment_rate(cr, uid, ids, vals, currency_id, date, ttype, journal_id, amount, context=context)
        for key in vals.keys():
            res[key].update(vals[key])
        for key in vals2.keys():
            res[key].update(vals2[key])
        #TODO: can probably be removed now
        #TODO: onchange_partner_id() should not returns [pre_line, line_dr_ids, payment_rate...] for type sale, and not 
        # [pre_line, line_cr_ids, payment_rate...] for type purchase.
        # We should definitively split account.voucher object in two and make distinct on_change functions. In the 
        # meanwhile, bellow lines must be there because the fields aren't present in the view, what crashes if the 
        # onchange returns a value for them
        if ttype == 'sale':
            del(res['value']['line_dr_ids'])
            del(res['value']['pre_line'])
            del(res['value']['payment_rate'])
        elif ttype == 'purchase':
            del(res['value']['line_cr_ids'])
            del(res['value']['pre_line'])
            del(res['value']['payment_rate'])
        return res

    def recompute_voucher_lines(self, cr, uid, ids, partner_id, journal_id, price, currency_id, ttype, date, context=None):
        """
        Returns a dict that contains new values and context

        @param partner_id: latest value from user input for field partner_id
        @param args: other arguments
        @param context: context arguments, like lang, time zone

        @return: Returns a dict which contains new values, and context
        """
        def _remove_noise_in_o2m():
            """if the line is partially reconciled, then we must pay attention to display it only once and
                in the good o2m.
                This function returns True if the line is considered as noise and should not be displayed
            """
            if line.reconcile_partial_id:
                if currency_id == line.currency_id.id:
                    if line.amount_residual_currency <= 0:
                        return True
                else:
                    if line.amount_residual <= 0:
                        return True
            return False

        if context is None:
            context = {}
        context_multi_currency = context.copy()

        currency_pool = self.pool.get('res.currency')
        move_line_pool = self.pool.get('account.move.line')
        partner_pool = self.pool.get('res.partner')
        journal_pool = self.pool.get('account.journal')
        line_pool = self.pool.get('account.voucher.line')

        #set default values
        default = {
            'value': {'line_dr_ids': [], 'line_cr_ids': [], 'pre_line': False},
        }

        # drop existing lines
        line_ids = ids and line_pool.search(cr, uid, [('voucher_id', '=', ids[0])])
        for line in line_pool.browse(cr, uid, line_ids, context=context):
            if line.type == 'cr':
                default['value']['line_cr_ids'].append((2, line.id))
            else:
                default['value']['line_dr_ids'].append((2, line.id))

        if not partner_id or not journal_id:
            return default

        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        partner = partner_pool.browse(cr, uid, partner_id, context=context)
        currency_id = currency_id or journal.company_id.currency_id.id

        total_credit = 0.0
        total_debit = 0.0
        account_type = None
        if context.get('account_id'):
            account_type = self.pool['account.account'].browse(cr, uid, context['account_id'], context=context).type
        if ttype == 'payment':
            if not account_type:
                account_type = 'payable'
            total_debit = price or 0.0
        else:
            total_credit = price or 0.0
            if not account_type:
                account_type = 'receivable'

        if not context.get('move_line_ids', False):
            ids = move_line_pool.search(cr, uid, [('state','=','valid'), ('account_id.type', '=', account_type), ('reconcile_id', '=', False), ('partner_id', '=', partner_id)], context=context)
        else:
            ids = context['move_line_ids']
        invoice_id = context.get('invoice_id', False)
        company_currency = journal.company_id.currency_id.id
        move_lines_found = []

        #order the lines by most old first
        ids.reverse()
        account_move_lines = move_line_pool.browse(cr, uid, ids, context=context)

        #compute the total debit/credit and look for a matching open amount or invoice
        for line in account_move_lines:
            if _remove_noise_in_o2m():
                continue

            if invoice_id:
                if line.invoice.id == invoice_id:
                    #if the invoice linked to the voucher line is equal to the invoice_id in context
                    #then we assign the amount on that line, whatever the other voucher lines
                    move_lines_found.append(line.id)
            elif currency_id == company_currency:
                #otherwise treatments is the same but with other field names
                if line.amount_residual == price:
                    #if the amount residual is equal the amount voucher, we assign it to that voucher
                    #line, whatever the other voucher lines
                    move_lines_found.append(line.id)
                    break
                #otherwise we will split the voucher amount on each line (by most old first)
                total_credit += line.credit or 0.0
                total_debit += line.debit or 0.0
            elif currency_id == line.currency_id.id:
                if line.amount_residual_currency == price:
                    move_lines_found.append(line.id)
                    break
                total_credit += line.credit and line.amount_currency or 0.0
                total_debit += line.debit and line.amount_currency or 0.0

        remaining_amount = price
        #voucher line creation
        for line in account_move_lines:

            if _remove_noise_in_o2m():
                continue

            if line.currency_id and currency_id == line.currency_id.id:
                amount_original = abs(line.amount_currency)
                amount_unreconciled = abs(line.amount_residual_currency)
            else:
                #always use the amount booked in the company currency as the basis of the conversion into the voucher currency
                amount_original = currency_pool.compute(cr, uid, company_currency, currency_id, line.credit or line.debit or 0.0, context=context_multi_currency)
                amount_unreconciled = currency_pool.compute(cr, uid, company_currency, currency_id, abs(line.amount_residual), context=context_multi_currency)
            line_currency_id = line.currency_id and line.currency_id.id or company_currency
            rs = {
                'name':line.move_id.name,
                'type': line.credit and 'dr' or 'cr',
                'move_line_id':line.id,
                'account_id':line.account_id.id,
                'amount_original': amount_original,
                'amount': (line.id in move_lines_found) and min(abs(remaining_amount), amount_unreconciled) or 0.0,
                'date_original':line.date,
                'date_due':line.date_maturity,
                'amount_unreconciled': amount_unreconciled,
                'currency_id': line_currency_id,
            }
            remaining_amount -= rs['amount']
            #in case a corresponding move_line hasn't been found, we now try to assign the voucher amount
            #on existing invoices: we split voucher amount by most old first, but only for lines in the same currency
            if not move_lines_found:
                if currency_id == line_currency_id:
                    if line.credit:
                        amount = min(amount_unreconciled, abs(total_debit))
                        rs['amount'] = amount
                        total_debit -= amount
                    else:
                        amount = min(amount_unreconciled, abs(total_credit))
                        rs['amount'] = amount
                        total_credit -= amount

            if rs['amount_unreconciled'] == rs['amount']:
                rs['reconcile'] = True

            if rs['type'] == 'cr':
                default['value']['line_cr_ids'].append(rs)
            else:
                default['value']['line_dr_ids'].append(rs)

            if len(default['value']['line_cr_ids']) > 0:
                default['value']['pre_line'] = 1
            elif len(default['value']['line_dr_ids']) > 0:
                default['value']['pre_line'] = 1
            default['value']['writeoff_amount'] = self._compute_writeoff_amount(cr, uid, default['value']['line_dr_ids'], default['value']['line_cr_ids'], price, ttype)
        return default

    def onchange_payment_rate_currency(self, cr, uid, ids, currency_id, payment_rate, payment_rate_currency_id, date, amount, company_id, context=None):
        if context is None:
            context = {}
        res = {'value': {}}
        if currency_id:
            #set the default payment rate of the voucher and compute the paid amount in company currency
            ctx = context.copy()
            ctx.update({'date': date})
            #read the voucher rate with the right date in the context
            voucher_rate = self.pool.get('res.currency').read(cr, uid, [currency_id], ['rate'], context=ctx)[0]['rate']
            ctx.update({
                'voucher_special_currency_rate': payment_rate * voucher_rate, 
                'voucher_special_currency': payment_rate_currency_id})
            vals = self.onchange_rate(cr, uid, ids, payment_rate, amount, currency_id, payment_rate_currency_id, company_id, context=ctx)
            for key in vals.keys():
                res[key].update(vals[key])
        return res

    def onchange_date(self, cr, uid, ids, date, currency_id, payment_rate_currency_id, amount, company_id, context=None):
        """
        @param date: latest value from user input for field date
        @param args: other arguments
        @param context: context arguments, like lang, time zone
        @return: Returns a dict which contains new values, and context
        """
        if context is None:
            context ={}
        res = {'value': {}}
        #set the period of the voucher
        period_pool = self.pool.get('account.period')
        currency_obj = self.pool.get('res.currency')
        ctx = context.copy()
        ctx.update({'company_id': company_id, 'account_period_prefer_normal': True})
        voucher_currency_id = currency_id or self.pool.get('res.company').browse(cr, uid, company_id, context=ctx).currency_id.id
        pids = period_pool.find(cr, uid, date, context=ctx)
        if pids:
            res['value'].update({'period_id':pids[0]})
        if payment_rate_currency_id:
            ctx.update({'date': date})
            payment_rate = 1.0
            if payment_rate_currency_id != currency_id:
                tmp = currency_obj.browse(cr, uid, payment_rate_currency_id, context=ctx).rate
                payment_rate = tmp / currency_obj.browse(cr, uid, voucher_currency_id, context=ctx).rate
            vals = self.onchange_payment_rate_currency(cr, uid, ids, voucher_currency_id, payment_rate, payment_rate_currency_id, date, amount, company_id, context=context)
            vals['value'].update({'payment_rate': payment_rate})
            for key in vals.keys():
                res[key].update(vals[key])
        return res

    def onchange_journal(self, cr, uid, ids, journal_id, line_ids, tax_id, partner_id, date, amount, ttype, company_id, context=None):
        if context is None:
            context = {}
        if not journal_id:
            return False
        journal_pool = self.pool.get('account.journal')
        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        if ttype in ('sale', 'receipt'):
            account_id = journal.default_debit_account_id
        elif ttype in ('purchase', 'payment'):
            account_id = journal.default_credit_account_id
        else:
            account_id = journal.default_credit_account_id or journal.default_debit_account_id
        tax_id = False
        if account_id and account_id.tax_ids:
            tax_id = account_id.tax_ids[0].id

        vals = {'value':{} }
        if ttype in ('sale', 'purchase'):
            vals = self.onchange_price(cr, uid, ids, line_ids, tax_id, partner_id, context)
            vals['value'].update({'tax_id':tax_id,'amount': amount})
        currency_id = False
        if journal.currency:
            currency_id = journal.currency.id
        else:
            currency_id = journal.company_id.currency_id.id

        period_ids = self.pool['account.period'].find(cr, uid, dt=date, context=dict(context, company_id=company_id))
        vals['value'].update({
            'currency_id': currency_id,
            'payment_rate_currency_id': currency_id,
            'period_id': period_ids and period_ids[0] or False
        })
        #in case we want to register the payment directly from an invoice, it's confusing to allow to switch the journal 
        #without seeing that the amount is expressed in the journal currency, and not in the invoice currency. So to avoid
        #this common mistake, we simply reset the amount to 0 if the currency is not the invoice currency.
        if context.get('payment_expected_currency') and currency_id != context.get('payment_expected_currency'):
            vals['value']['amount'] = 0
            amount = 0
        if partner_id:
            res = self.onchange_partner_id(cr, uid, ids, partner_id, journal_id, amount, currency_id, ttype, date, context)
            for key in res.keys():
                vals[key].update(res[key])
        return vals

    def onchange_company(self, cr, uid, ids, partner_id, journal_id, currency_id, company_id, context=None):
        """
        If the company changes, check that the journal is in the right company.
        If not, fetch a new journal.
        """
        journal_pool = self.pool['account.journal']
        journal = journal_pool.browse(cr, uid, journal_id, context=context)
        if journal.company_id.id != company_id:
            # can not guess type of journal, better remove it
            return {'value': {'journal_id': False}}
        return {}

    def button_proforma_voucher(self, cr, uid, ids, context=None):
        self.signal_workflow(cr, uid, ids, 'proforma_voucher')
        return {'type': 'ir.actions.act_window_close'}

    def proforma_voucher(self, cr, uid, ids, context=None):
        self.action_move_line_create(cr, uid, ids, context=context)
        return True

    def action_cancel_draft(self, cr, uid, ids, context=None):
        self.create_workflow(cr, uid, ids)
        self.write(cr, uid, ids, {'state':'draft'})
        return True

    def cancel_voucher(self, cr, uid, ids, context=None):
        reconcile_pool = self.pool.get('account.move.reconcile')
        move_pool = self.pool.get('account.move')
        move_line_pool = self.pool.get('account.move.line')
        for voucher in self.browse(cr, uid, ids, context=context):
            # refresh to make sure you don't unlink an already removed move
            voucher.refresh()
            for line in voucher.move_ids:
                # refresh to make sure you don't unreconcile an already unreconciled entry
                line.refresh()
                if line.reconcile_id:
                    move_lines = [move_line.id for move_line in line.reconcile_id.line_id]
                    move_lines.remove(line.id)
                    reconcile_pool.unlink(cr, uid, [line.reconcile_id.id])
                    if len(move_lines) >= 2:
                        move_line_pool.reconcile_partial(cr, uid, move_lines, 'auto',context=context)
            if voucher.move_id:
                move_pool.button_cancel(cr, uid, [voucher.move_id.id])
                move_pool.unlink(cr, uid, [voucher.move_id.id])
        res = {
            'state':'cancel',
            'move_id':False,
        }
        self.write(cr, uid, ids, res)
        return True

    def unlink(self, cr, uid, ids, context=None):
        for t in self.read(cr, uid, ids, ['state'], context=context):
            if t['state'] not in ('draft', 'cancel'):
                raise osv.except_osv(_('Invalid Action!'), _('Cannot delete voucher(s) which are already opened or paid.'))
        return super(account_voucher, self).unlink(cr, uid, ids, context=context)

    def onchange_payment(self, cr, uid, ids, pay_now, journal_id, partner_id, ttype='sale'):
        res = {}
        if not partner_id:
            return res
        res = {}
        partner_pool = self.pool.get('res.partner')
        journal_pool = self.pool.get('account.journal')
        if pay_now == 'pay_later':
            partner = partner_pool.browse(cr, uid, partner_id)
            journal = journal_pool.browse(cr, uid, journal_id)
            if journal.type in ('sale','sale_refund'):
                account_id = partner.property_account_receivable.id
            elif journal.type in ('purchase', 'purchase_refund','expense'):
                account_id = partner.property_account_payable.id
            elif ttype in ('sale', 'receipt'):
                account_id = journal.default_debit_account_id.id
            elif ttype in ('purchase', 'payment'):
                account_id = journal.default_credit_account_id.id
            else:
                account_id = journal.default_credit_account_id.id or journal.default_debit_account_id.id
            if account_id:
                res['account_id'] = account_id
        return {'value':res}

    def _sel_context(self, cr, uid, voucher_id, context=None):
        """
        Select the context to use accordingly if it needs to be multicurrency or not.

        :param voucher_id: Id of the actual voucher
        :return: The returned context will be the same as given in parameter if the voucher currency is the same
                 than the company currency, otherwise it's a copy of the parameter with an extra key 'date' containing
                 the date of the voucher.
        :rtype: dict
        """
        company_currency = self._get_company_currency(cr, uid, voucher_id, context)
        current_currency = self._get_current_currency(cr, uid, voucher_id, context)
        if current_currency <> company_currency:
            context_multi_currency = context.copy()
            voucher = self.pool.get('account.voucher').browse(cr, uid, voucher_id, context)
            context_multi_currency.update({'date': voucher.date})
            return context_multi_currency
        return context

    def first_move_line_get(self, cr, uid, voucher_id, move_id, company_currency, current_currency, context=None):
        '''
        Return a dict to be use to create the first account move line of given voucher.

        :param voucher_id: Id of voucher what we are creating account_move.
        :param move_id: Id of account move where this line will be added.
        :param company_currency: id of currency of the company to which the voucher belong
        :param current_currency: id of currency of the voucher
        :return: mapping between fieldname and value of account move line to create
        :rtype: dict
        '''
        voucher = self.pool.get('account.voucher').browse(cr,uid,voucher_id,context)
        debit = credit = 0.0
        # TODO: is there any other alternative then the voucher type ??
        # ANSWER: We can have payment and receipt "In Advance".
        # TODO: Make this logic available.
        # -for sale, purchase we have but for the payment and receipt we do not have as based on the bank/cash journal we can not know its payment or receipt
        if voucher.type in ('purchase', 'payment'):
            credit = voucher.paid_amount_in_company_currency
        elif voucher.type in ('sale', 'receipt'):
            debit = voucher.paid_amount_in_company_currency
        if debit < 0: credit = -debit; debit = 0.0
        if credit < 0: debit = -credit; credit = 0.0
        sign = debit - credit < 0 and -1 or 1
        #set the first line of the voucher
        move_line = {
                'name': voucher.name or '/',
                'debit': debit,
                'credit': credit,
                'account_id': voucher.account_id.id,
                'move_id': move_id,
                'journal_id': voucher.journal_id.id,
                'period_id': voucher.period_id.id,
                'partner_id': voucher.partner_id.id,
                'currency_id': company_currency <> current_currency and  current_currency or False,
                'amount_currency': (sign * abs(voucher.amount) # amount < 0 for refunds
                    if company_currency != current_currency else 0.0),
                'date': voucher.date,
                'date_maturity': voucher.date_due
            }
        return move_line

    def account_move_get(self, cr, uid, voucher_id, context=None):
        '''
        This method prepare the creation of the account move related to the given voucher.

        :param voucher_id: Id of voucher for which we are creating account_move.
        :return: mapping between fieldname and value of account move to create
        :rtype: dict
        '''
        seq_obj = self.pool.get('ir.sequence')
        voucher = self.pool.get('account.voucher').browse(cr,uid,voucher_id,context)
        if voucher.number:
            name = voucher.number
        elif voucher.journal_id.sequence_id:
            if not voucher.journal_id.sequence_id.active:
                raise osv.except_osv(_('Configuration Error !'),
                    _('Please activate the sequence of selected journal !'))
            c = dict(context)
            c.update({'fiscalyear_id': voucher.period_id.fiscalyear_id.id})
            name = seq_obj.next_by_id(cr, uid, voucher.journal_id.sequence_id.id, context=c)
        else:
            raise osv.except_osv(_('Error!'),
                        _('Please define a sequence on the journal.'))
        if not voucher.reference:
            ref = name.replace('/','')
        else:
            ref = voucher.reference

        move = {
            'name': name,
            'journal_id': voucher.journal_id.id,
            'narration': voucher.narration,
            'date': voucher.date,
            'ref': ref,
            'period_id': voucher.period_id.id,
        }
        return move

    def _get_exchange_lines(self, cr, uid, line, move_id, amount_residual, company_currency, current_currency, context=None):
        '''
        Prepare the two lines in company currency due to currency rate difference.

        :param line: browse record of the voucher.line for which we want to create currency rate difference accounting
            entries
        :param move_id: Account move wher the move lines will be.
        :param amount_residual: Amount to be posted.
        :param company_currency: id of currency of the company to which the voucher belong
        :param current_currency: id of currency of the voucher
        :return: the account move line and its counterpart to create, depicted as mapping between fieldname and value
        :rtype: tuple of dict
        '''
        if amount_residual > 0:
            account_id = line.voucher_id.company_id.expense_currency_exchange_account_id
            if not account_id:
                model, action_id = self.pool['ir.model.data'].get_object_reference(cr, uid, 'account', 'action_account_form')
                msg = _("You should configure the 'Loss Exchange Rate Account' to manage automatically the booking of accounting entries related to differences between exchange rates.")
                raise openerp.exceptions.RedirectWarning(msg, action_id, _('Go to the configuration panel'))
        else:
            account_id = line.voucher_id.company_id.income_currency_exchange_account_id
            if not account_id:
                model, action_id = self.pool['ir.model.data'].get_object_reference(cr, uid, 'account', 'action_account_form')
                msg = _("You should configure the 'Gain Exchange Rate Account' to manage automatically the booking of accounting entries related to differences between exchange rates.")
                raise openerp.exceptions.RedirectWarning(msg, action_id, _('Go to the configuration panel'))
        # Even if the amount_currency is never filled, we need to pass the foreign currency because otherwise
        # the receivable/payable account may have a secondary currency, which render this field mandatory
        if line.account_id.currency_id:
            account_currency_id = line.account_id.currency_id.id
        else:
            account_currency_id = company_currency <> current_currency and current_currency or False
        move_line = {
            'journal_id': line.voucher_id.journal_id.id,
            'period_id': line.voucher_id.period_id.id,
            'name': _('change')+': '+(line.name or '/'),
            'account_id': line.account_id.id,
            'move_id': move_id,
            'partner_id': line.voucher_id.partner_id.id,
            'currency_id': account_currency_id,
            'amount_currency': 0.0,
            'quantity': 1,
            'credit': amount_residual > 0 and amount_residual or 0.0,
            'debit': amount_residual < 0 and -amount_residual or 0.0,
            'date': line.voucher_id.date,
        }
        move_line_counterpart = {
            'journal_id': line.voucher_id.journal_id.id,
            'period_id': line.voucher_id.period_id.id,
            'name': _('change')+': '+(line.name or '/'),
            'account_id': account_id.id,
            'move_id': move_id,
            'amount_currency': 0.0,
            'partner_id': line.voucher_id.partner_id.id,
            'currency_id': account_currency_id,
            'quantity': 1,
            'debit': amount_residual > 0 and amount_residual or 0.0,
            'credit': amount_residual < 0 and -amount_residual or 0.0,
            'date': line.voucher_id.date,
        }
        return (move_line, move_line_counterpart)

    def _convert_amount(self, cr, uid, amount, voucher_id, context=None):
        '''
        This function convert the amount given in company currency. It takes either the rate in the voucher (if the
        payment_rate_currency_id is relevant) either the rate encoded in the system.

        :param amount: float. The amount to convert
        :param voucher: id of the voucher on which we want the conversion
        :param context: to context to use for the conversion. It may contain the key 'date' set to the voucher date
            field in order to select the good rate to use.
        :return: the amount in the currency of the voucher's company
        :rtype: float
        '''
        if context is None:
            context = {}
        currency_obj = self.pool.get('res.currency')
        voucher = self.browse(cr, uid, voucher_id, context=context)
        return currency_obj.compute(cr, uid, voucher.currency_id.id, voucher.company_id.currency_id.id, amount, context=context)

    def voucher_move_line_create(self, cr, uid, voucher_id, line_total, move_id, company_currency, current_currency, context=None):
        '''
        Create one account move line, on the given account move, per voucher line where amount is not 0.0.
        It returns Tuple with tot_line what is total of difference between debit and credit and
        a list of lists with ids to be reconciled with this format (total_deb_cred,list_of_lists).

        :param voucher_id: Voucher id what we are working with
        :param line_total: Amount of the first line, which correspond to the amount we should totally split among all voucher lines.
        :param move_id: Account move wher those lines will be joined.
        :param company_currency: id of currency of the company to which the voucher belong
        :param current_currency: id of currency of the voucher
        :return: Tuple build as (remaining amount not allocated on voucher lines, list of account_move_line created in this method)
        :rtype: tuple(float, list of int)
        '''
        if context is None:
            context = {}
        move_line_obj = self.pool.get('account.move.line')
        currency_obj = self.pool.get('res.currency')
        tax_obj = self.pool.get('account.tax')
        tot_line = line_total
        rec_lst_ids = []

        date = self.read(cr, uid, [voucher_id], ['date'], context=context)[0]['date']
        ctx = context.copy()
        ctx.update({'date': date})
        voucher = self.pool.get('account.voucher').browse(cr, uid, voucher_id, context=ctx)
        voucher_currency = voucher.journal_id.currency or voucher.company_id.currency_id
        ctx.update({
            'voucher_special_currency_rate': voucher_currency.rate * voucher.payment_rate ,
            'voucher_special_currency': voucher.payment_rate_currency_id and voucher.payment_rate_currency_id.id or False,})
        prec = self.pool.get('decimal.precision').precision_get(cr, uid, 'Account')
        for line in voucher.line_ids:
            #create one move line per voucher line where amount is not 0.0
            # AND (second part of the clause) only if the original move line was not having debit = credit = 0 (which is a legal value)
            if not line.amount and not (line.move_line_id and not float_compare(line.move_line_id.debit, line.move_line_id.credit, precision_digits=prec) and not float_compare(line.move_line_id.debit, 0.0, precision_digits=prec)):
                continue
            # convert the amount set on the voucher line into the currency of the voucher's company
            # this calls res_curreny.compute() with the right context, so that it will take either the rate on the voucher if it is relevant or will use the default behaviour
            amount = self._convert_amount(cr, uid, line.untax_amount or line.amount, voucher.id, context=ctx)
            # if the amount encoded in voucher is equal to the amount unreconciled, we need to compute the
            # currency rate difference
            if line.amount == line.amount_unreconciled:
                if not line.move_line_id:
                    raise osv.except_osv(_('Wrong voucher line'),_("The invoice you are willing to pay is not valid anymore."))
                sign = line.type =='dr' and -1 or 1
                currency_rate_difference = sign * (line.move_line_id.amount_residual - amount)
            else:
                currency_rate_difference = 0.0
            move_line = {
                'journal_id': voucher.journal_id.id,
                'period_id': voucher.period_id.id,
                'name': line.name or '/',
                'account_id': line.account_id.id,
                'move_id': move_id,
                'partner_id': voucher.partner_id.id,
                'currency_id': line.move_line_id and (company_currency <> line.move_line_id.currency_id.id and line.move_line_id.currency_id.id) or False,
                'analytic_account_id': line.account_analytic_id and line.account_analytic_id.id or False,
                'quantity': 1,
                'credit': 0.0,
                'debit': 0.0,
                'date': voucher.date
            }
            if amount < 0:
                amount = -amount
                if line.type == 'dr':
                    line.type = 'cr'
                else:
                    line.type = 'dr'

            if (line.type=='dr'):
                tot_line += amount
                move_line['debit'] = amount
            else:
                tot_line -= amount
                move_line['credit'] = amount

            if voucher.tax_id and voucher.type in ('sale', 'purchase'):
                move_line.update({
                    'account_tax_id': voucher.tax_id.id,
                })

            # compute the amount in foreign currency
            foreign_currency_diff = 0.0
            amount_currency = False
            if line.move_line_id:
                # We want to set it on the account move line as soon as the original line had a foreign currency
                if line.move_line_id.currency_id and line.move_line_id.currency_id.id != company_currency:
                    # we compute the amount in that foreign currency.
                    if line.move_line_id.currency_id.id == current_currency:
                        # if the voucher and the voucher line share the same currency, there is no computation to do
                        sign = (move_line['debit'] - move_line['credit']) < 0 and -1 or 1
                        amount_currency = sign * (line.amount)
                    else:
                        # if the rate is specified on the voucher, it will be used thanks to the special keys in the context
                        # otherwise we use the rates of the system
                        amount_currency = currency_obj.compute(cr, uid, company_currency, line.move_line_id.currency_id.id, move_line['debit']-move_line['credit'], context=ctx)
                if line.amount == line.amount_unreconciled:
                    foreign_currency_diff = line.move_line_id.amount_residual_currency - abs(amount_currency)

            move_line['amount_currency'] = amount_currency
            voucher_line = move_line_obj.create(cr, uid, move_line)
            rec_ids = [voucher_line, line.move_line_id.id]

            if not currency_obj.is_zero(cr, uid, voucher.company_id.currency_id, currency_rate_difference):
                # Change difference entry in company currency
                exch_lines = self._get_exchange_lines(cr, uid, line, move_id, currency_rate_difference, company_currency, current_currency, context=context)
                new_id = move_line_obj.create(cr, uid, exch_lines[0],context)
                move_line_obj.create(cr, uid, exch_lines[1], context)
                rec_ids.append(new_id)

            if line.move_line_id and line.move_line_id.currency_id and not currency_obj.is_zero(cr, uid, line.move_line_id.currency_id, foreign_currency_diff):
                # Change difference entry in voucher currency
                move_line_foreign_currency = {
                    'journal_id': line.voucher_id.journal_id.id,
                    'period_id': line.voucher_id.period_id.id,
                    'name': _('change')+': '+(line.name or '/'),
                    'account_id': line.account_id.id,
                    'move_id': move_id,
                    'partner_id': line.voucher_id.partner_id.id,
                    'currency_id': line.move_line_id.currency_id.id,
                    'amount_currency': -1 * foreign_currency_diff,
                    'quantity': 1,
                    'credit': 0.0,
                    'debit': 0.0,
                    'date': line.voucher_id.date,
                }
                new_id = move_line_obj.create(cr, uid, move_line_foreign_currency, context=context)
                rec_ids.append(new_id)
            if line.move_line_id.id:
                rec_lst_ids.append(rec_ids)
        return (tot_line, rec_lst_ids)

    def writeoff_move_line_get(self, cr, uid, voucher_id, line_total, move_id, name, company_currency, current_currency, context=None):
        '''
        Set a dict to be use to create the writeoff move line.

        :param voucher_id: Id of voucher what we are creating account_move.
        :param line_total: Amount remaining to be allocated on lines.
        :param move_id: Id of account move where this line will be added.
        :param name: Description of account move line.
        :param company_currency: id of currency of the company to which the voucher belong
        :param current_currency: id of currency of the voucher
        :return: mapping between fieldname and value of account move line to create
        :rtype: dict
        '''
        currency_obj = self.pool.get('res.currency')
        move_line = {}

        voucher = self.pool.get('account.voucher').browse(cr,uid,voucher_id,context)
        current_currency_obj = voucher.currency_id or voucher.journal_id.company_id.currency_id

        if not currency_obj.is_zero(cr, uid, current_currency_obj, line_total):
            diff = line_total
            account_id = False
            write_off_name = ''
            if voucher.payment_option == 'with_writeoff':
                account_id = voucher.writeoff_acc_id.id
                write_off_name = voucher.comment
            elif voucher.partner_id:
                if voucher.type in ('sale', 'receipt'):
                    account_id = voucher.partner_id.property_account_receivable.id
                else:
                    account_id = voucher.partner_id.property_account_payable.id
            else:
                # fallback on account of voucher
                account_id = voucher.account_id.id
            sign = voucher.type == 'payment' and -1 or 1
            move_line = {
                'name': write_off_name or name,
                'account_id': account_id,
                'move_id': move_id,
                'partner_id': voucher.partner_id.id,
                'date': voucher.date,
                'credit': diff > 0 and diff or 0.0,
                'debit': diff < 0 and -diff or 0.0,
                'amount_currency': company_currency <> current_currency and (sign * -1 * voucher.writeoff_amount) or 0.0,
                'currency_id': company_currency <> current_currency and current_currency or False,
                'analytic_account_id': voucher.analytic_id and voucher.analytic_id.id or False,
            }

        return move_line

    def _get_company_currency(self, cr, uid, voucher_id, context=None):
        '''
        Get the currency of the actual company.

        :param voucher_id: Id of the voucher what i want to obtain company currency.
        :return: currency id of the company of the voucher
        :rtype: int
        '''
        return self.pool.get('account.voucher').browse(cr,uid,voucher_id,context).journal_id.company_id.currency_id.id

    def _get_current_currency(self, cr, uid, voucher_id, context=None):
        '''
        Get the currency of the voucher.

        :param voucher_id: Id of the voucher what i want to obtain current currency.
        :return: currency id of the voucher
        :rtype: int
        '''
        voucher = self.pool.get('account.voucher').browse(cr,uid,voucher_id,context)
        return voucher.currency_id.id or self._get_company_currency(cr,uid,voucher.id,context)

    def action_move_line_create(self, cr, uid, ids, context=None):
        '''
        Confirm the vouchers given in ids and create the journal entries for each of them
        '''
        if context is None:
            context = {}
        move_pool = self.pool.get('account.move')
        move_line_pool = self.pool.get('account.move.line')
        for voucher in self.browse(cr, uid, ids, context=context):
            local_context = dict(context, force_company=voucher.journal_id.company_id.id)
            if voucher.move_id:
                continue
            company_currency = self._get_company_currency(cr, uid, voucher.id, context)
            current_currency = self._get_current_currency(cr, uid, voucher.id, context)
            # we select the context to use accordingly if it's a multicurrency case or not
            context = self._sel_context(cr, uid, voucher.id, context)
            # But for the operations made by _convert_amount, we always need to give the date in the context
            ctx = context.copy()
            ctx.update({'date': voucher.date})
            # Create the account move record.
            move_id = move_pool.create(cr, uid, self.account_move_get(cr, uid, voucher.id, context=context), context=context)
            # Get the name of the account_move just created
            name = move_pool.browse(cr, uid, move_id, context=context).name
            # Create the first line of the voucher
            move_line_id = move_line_pool.create(cr, uid, self.first_move_line_get(cr,uid,voucher.id, move_id, company_currency, current_currency, local_context), local_context)
            move_line_brw = move_line_pool.browse(cr, uid, move_line_id, context=context)
            line_total = move_line_brw.debit - move_line_brw.credit
            rec_list_ids = []
            if voucher.type == 'sale':
                line_total = line_total - self._convert_amount(cr, uid, voucher.tax_amount, voucher.id, context=ctx)
            elif voucher.type == 'purchase':
                line_total = line_total + self._convert_amount(cr, uid, voucher.tax_amount, voucher.id, context=ctx)
            # Create one move line per voucher line where amount is not 0.0
            line_total, rec_list_ids = self.voucher_move_line_create(cr, uid, voucher.id, line_total, move_id, company_currency, current_currency, context)

            # Create the writeoff line if needed
            ml_writeoff = self.writeoff_move_line_get(cr, uid, voucher.id, line_total, move_id, name, company_currency, current_currency, local_context)
            if ml_writeoff:
                move_line_pool.create(cr, uid, ml_writeoff, local_context)
            # We post the voucher.
            self.write(cr, uid, [voucher.id], {
                'move_id': move_id,
                'state': 'posted',
                'number': name,
            })
            if voucher.journal_id.entry_posted:
                move_pool.post(cr, uid, [move_id], context={})
            # We automatically reconcile the account move lines.
            reconcile = False
            for rec_ids in rec_list_ids:
                if len(rec_ids) >= 2:
                    reconcile = move_line_pool.reconcile_partial(cr, uid, rec_ids, writeoff_acc_id=voucher.writeoff_acc_id.id, writeoff_period_id=voucher.period_id.id, writeoff_journal_id=voucher.journal_id.id)
        return True

class account_voucher_line(osv.osv):
    _name = 'account.voucher.line'
    _description = 'Voucher Lines'
    _order = "move_line_id"

    # If the payment is in the same currency than the invoice, we keep the same amount
    # Otherwise, we compute from invoice currency to payment currency
    def _compute_balance(self, cr, uid, ids, name, args, context=None):
        currency_pool = self.pool.get('res.currency')
        rs_data = {}
        for line in self.browse(cr, uid, ids, context=context):
            ctx = context.copy()
            ctx.update({'date': line.voucher_id.date})
            voucher_rate = self.pool.get('res.currency').read(cr, uid, line.voucher_id.currency_id.id, ['rate'], context=ctx)['rate']
            ctx.update({
                'voucher_special_currency': line.voucher_id.payment_rate_currency_id and line.voucher_id.payment_rate_currency_id.id or False,
                'voucher_special_currency_rate': line.voucher_id.payment_rate * voucher_rate})
            res = {}
            company_currency = line.voucher_id.journal_id.company_id.currency_id.id
            voucher_currency = line.voucher_id.currency_id and line.voucher_id.currency_id.id or company_currency
            move_line = line.move_line_id or False

            if not move_line:
                res['amount_original'] = 0.0
                res['amount_unreconciled'] = 0.0
            elif move_line.currency_id and voucher_currency==move_line.currency_id.id:
                res['amount_original'] = abs(move_line.amount_currency)
                res['amount_unreconciled'] = abs(move_line.amount_residual_currency)
            else:
                #always use the amount booked in the company currency as the basis of the conversion into the voucher currency
                res['amount_original'] = currency_pool.compute(cr, uid, company_currency, voucher_currency, move_line.credit or move_line.debit or 0.0, context=ctx)
                res['amount_unreconciled'] = currency_pool.compute(cr, uid, company_currency, voucher_currency, abs(move_line.amount_residual), context=ctx)

            rs_data[line.id] = res
        return rs_data

    def _currency_id(self, cr, uid, ids, name, args, context=None):
        '''
        This function returns the currency id of a voucher line. It's either the currency of the
        associated move line (if any) or the currency of the voucher or the company currency.
        '''
        res = {}
        for line in self.browse(cr, uid, ids, context=context):
            move_line = line.move_line_id
            if move_line:
                res[line.id] = move_line.currency_id and move_line.currency_id.id or move_line.company_id.currency_id.id
            else:
                res[line.id] = line.voucher_id.currency_id and line.voucher_id.currency_id.id or line.voucher_id.company_id.currency_id.id
        return res

    _columns = {
        'voucher_id':fields.many2one('account.voucher', 'Voucher', required=1, ondelete='cascade'),
        'name':fields.char('Description',),
        'account_id':fields.many2one('account.account','Account', required=True),
        'partner_id':fields.related('voucher_id', 'partner_id', type='many2one', relation='res.partner', string='Partner'),
        'untax_amount':fields.float('Untax Amount'),
        'amount':fields.float('Amount', digits_compute=dp.get_precision('Account')),
        'reconcile': fields.boolean('Full Reconcile'),
        'type':fields.selection([('dr','Debit'),('cr','Credit')], 'Dr/Cr'),
        'account_analytic_id':  fields.many2one('account.analytic.account', 'Analytic Account'),
        'move_line_id': fields.many2one('account.move.line', 'Journal Item', copy=False),
        'date_original': fields.related('move_line_id','date', type='date', relation='account.move.line', string='Date', readonly=1),
        'date_due': fields.related('move_line_id','date_maturity', type='date', relation='account.move.line', string='Due Date', readonly=1),
        'amount_original': fields.function(_compute_balance, multi='dc', type='float', string='Original Amount', store=True, digits_compute=dp.get_precision('Account')),
        'amount_unreconciled': fields.function(_compute_balance, multi='dc', type='float', string='Open Balance', store=True, digits_compute=dp.get_precision('Account')),
        'company_id': fields.related('voucher_id','company_id', relation='res.company', type='many2one', string='Company', store=True, readonly=True),
        'currency_id': fields.function(_currency_id, string='Currency', type='many2one', relation='res.currency', readonly=True),
    }
    _defaults = {
        'name': '',
    }

    def onchange_reconcile(self, cr, uid, ids, reconcile, amount, amount_unreconciled, context=None):
        vals = {'amount': 0.0}
        if reconcile:
            vals = { 'amount': amount_unreconciled}
        return {'value': vals}

    def onchange_amount(self, cr, uid, ids, amount, amount_unreconciled, context=None):
        vals = {}
        if amount:
            vals['reconcile'] = (amount == amount_unreconciled)
        return {'value': vals}

    def onchange_move_line_id(self, cr, user, ids, move_line_id, context=None):
        """
        Returns a dict that contains new values and context

        @param move_line_id: latest value from user input for field move_line_id
        @param args: other arguments
        @param context: context arguments, like lang, time zone

        @return: Returns a dict which contains new values, and context
        """
        res = {}
        move_line_pool = self.pool.get('account.move.line')
        if move_line_id:
            move_line = move_line_pool.browse(cr, user, move_line_id, context=context)
            if move_line.credit:
                ttype = 'dr'
            else:
                ttype = 'cr'
            res.update({
                'account_id': move_line.account_id.id,
                'type': ttype,
                'currency_id': move_line.currency_id and move_line.currency_id.id or move_line.company_id.currency_id.id,
            })
        return {
            'value':res,
        }

    def default_get(self, cr, user, fields_list, context=None):
        """
        Returns default values for fields
        @param fields_list: list of fields, for which default values are required to be read
        @param context: context arguments, like lang, time zone

        @return: Returns a dict that contains default values for fields
        """
        if context is None:
            context = {}
        journal_id = context.get('journal_id', False)
        partner_id = context.get('partner_id', False)
        journal_pool = self.pool.get('account.journal')
        partner_pool = self.pool.get('res.partner')
        values = super(account_voucher_line, self).default_get(cr, user, fields_list, context=context)
        if (not journal_id) or ('account_id' not in fields_list):
            return values
        journal = journal_pool.browse(cr, user, journal_id, context=context)
        account_id = False
        ttype = 'cr'
        if journal.type in ('sale', 'sale_refund'):
            account_id = journal.default_credit_account_id and journal.default_credit_account_id.id or False
            ttype = 'cr'
        elif journal.type in ('purchase', 'expense', 'purchase_refund'):
            account_id = journal.default_debit_account_id and journal.default_debit_account_id.id or False
            ttype = 'dr'
        elif partner_id:
            partner = partner_pool.browse(cr, user, partner_id, context=context)
            if context.get('type') == 'payment':
                ttype = 'dr'
                account_id = partner.property_account_payable.id
            elif context.get('type') == 'receipt':
                account_id = partner.property_account_receivable.id

        values.update({
            'account_id':account_id,
            'type':ttype
        })
        return values

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