# Copyright 1996-2015 PSERC. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

"""Converts external to internal indexing.
"""

import sys

from warnings import warn

from copy import deepcopy

from numpy import array, zeros, argsort, arange, concatenate
from numpy import flatnonzero as find

from scipy.sparse import issparse, vstack, hstack, csr_matrix as sparse

from pypower.idx_bus import PQ, PV, REF, NONE, BUS_I, BUS_TYPE
from pypower.idx_gen import GEN_BUS, GEN_STATUS
from pypower.idx_brch import F_BUS, T_BUS, BR_STATUS
from pypower.idx_area import PRICE_REF_BUS

from pypower.e2i_field import e2i_field
from pypower.e2i_data import e2i_data

from pypower.run_userfcn import run_userfcn


def ext2int(ppc, val_or_field=None, ordering=None, dim=0):
    """Converts external to internal indexing.

    This function has two forms, the old form that operates on
    and returns individual matrices and the new form that operates
    on and returns an entire PYPOWER case dict.

    1.  C{ppc = ext2int(ppc)}

    If the input is a single PYPOWER case dict, then all isolated
    buses, off-line generators and branches are removed along with any
    generators, branches or areas connected to isolated buses. Then the
    buses are renumbered consecutively, beginning at 0, and the
    generators are sorted by increasing bus number. Any 'ext2int'
    callback routines registered in the case are also invoked
    automatically. All of the related
    indexing information and the original data matrices are stored under
    the 'order' key of the dict to be used by C{int2ext} to perform
    the reverse conversions. If the case is already using internal
    numbering it is returned unchanged.

    Example::
        ppc = ext2int(ppc)

    @see: L{int2ext}, L{e2i_field}, L{e2i_data}

    @author: Ray Zimmerman (PSERC Cornell)
    @author: Richard Lincoln
    """
    ppc = deepcopy(ppc)
    if val_or_field is None:  # nargin == 1
        first = 'order' not in ppc
        if first or ppc["order"]["state"] == 'e':
            ## initialize order
            if first:
                o = {
                        'ext':      {
                                'bus':      None,
                                'branch':   None,
                                'gen':      None
                            },
                        'bus':      { 'e2i':      None,
                                      'i2e':      None,
                                      'status':   {} },
                        'gen':      { 'e2i':      None,
                                      'i2e':      None,
                                      'status':   {} },
                        'branch':   { 'status': {} }
                    }
            else:
                o = ppc["order"]

            ## sizes
            nb = ppc["bus"].shape[0]
            ng = ppc["gen"].shape[0]
            ng0 = ng
            if 'A' in ppc:
                dc = True if ppc["A"].shape[1] < (2 * nb + 2 * ng) else False
            elif 'N' in ppc:
                dc = True if ppc["N"].shape[1] < (2 * nb + 2 * ng) else False
            else:
                dc = False

            ## save data matrices with external ordering
            if 'ext' not in o: o['ext'] = {}
            o["ext"]["bus"]    = ppc["bus"].copy()
            o["ext"]["branch"] = ppc["branch"].copy()
            o["ext"]["gen"]    = ppc["gen"].copy()
            if 'areas' in ppc:
                if len(ppc["areas"]) == 0: ## if areas field is empty
                    del ppc['areas']       ## delete it (so it's ignored)
                else:                      ## otherwise
                    o["ext"]["areas"] = ppc["areas"].copy()  ## save it

            ## check that all buses have a valid BUS_TYPE
            bt = ppc["bus"][:, BUS_TYPE]
            err = find(~((bt == PQ) | (bt == PV) | (bt == REF) | (bt == NONE)))
            if len(err) > 0:
                sys.stderr.write('ext2int: bus %d has an invalid BUS_TYPE\n' % err)

            ## determine which buses, branches, gens are connected and
            ## in-service
            n2i = sparse((range(nb), (ppc["bus"][:, BUS_I], zeros(nb))),
                         shape=(max(ppc["bus"][:, BUS_I]) + 1, 1))
            n2i = array( n2i.todense().flatten() )[0, :] # as 1D array
            bs = (bt != NONE)                               ## bus status
            o["bus"]["status"]["on"]  = find(  bs )         ## connected
            o["bus"]["status"]["off"] = find( ~bs )         ## isolated
            gs = ( (ppc["gen"][:, GEN_STATUS] > 0) &          ## gen status
                    bs[ n2i[ppc["gen"][:, GEN_BUS].astype(int)] ] )
            o["gen"]["status"]["on"]  = find(  gs )    ## on and connected
            o["gen"]["status"]["off"] = find( ~gs )    ## off or isolated
            brs = ( ppc["branch"][:, BR_STATUS].astype(int) &  ## branch status
                    bs[n2i[ppc["branch"][:, F_BUS].astype(int)]] &
                    bs[n2i[ppc["branch"][:, T_BUS].astype(int)]] ).astype(bool)
            o["branch"]["status"]["on"]  = find(  brs ) ## on and conn
            o["branch"]["status"]["off"] = find( ~brs )
            if 'areas' in ppc:
                ar = bs[ n2i[ppc["areas"][:, PRICE_REF_BUS].astype(int)] ]
                o["areas"] = {"status": {}}
                o["areas"]["status"]["on"]  = find(  ar )
                o["areas"]["status"]["off"] = find( ~ar )

            ## delete stuff that is "out"
            if len(o["bus"]["status"]["off"]) > 0:
#                ppc["bus"][o["bus"]["status"]["off"], :] = array([])
                ppc["bus"] = ppc["bus"][o["bus"]["status"]["on"], :]
            if len(o["branch"]["status"]["off"]) > 0:
#                ppc["branch"][o["branch"]["status"]["off"], :] = array([])
                ppc["branch"] = ppc["branch"][o["branch"]["status"]["on"], :]
            if len(o["gen"]["status"]["off"]) > 0:
#                ppc["gen"][o["gen"]["status"]["off"], :] = array([])
                ppc["gen"] = ppc["gen"][o["gen"]["status"]["on"], :]
            if 'areas' in ppc and (len(o["areas"]["status"]["off"]) > 0):
#                ppc["areas"][o["areas"]["status"]["off"], :] = array([])
                ppc["areas"] = ppc["areas"][o["areas"]["status"]["on"], :]

            ## update size
            nb = ppc["bus"].shape[0]

            ## apply consecutive bus numbering
            o["bus"]["i2e"] = ppc["bus"][:, BUS_I].copy()
            o["bus"]["e2i"] = zeros(int(max(o["bus"]["i2e"])) + 1)
            o["bus"]["e2i"][o["bus"]["i2e"].astype(int)] = arange(nb)
            ppc["bus"][:, BUS_I] = \
                o["bus"]["e2i"][ ppc["bus"][:, BUS_I].astype(int) ].copy()
            ppc["gen"][:, GEN_BUS] = \
                o["bus"]["e2i"][ ppc["gen"][:, GEN_BUS].astype(int) ].copy()
            ppc["branch"][:, F_BUS] = \
                o["bus"]["e2i"][ ppc["branch"][:, F_BUS].astype(int) ].copy()
            ppc["branch"][:, T_BUS] = \
                o["bus"]["e2i"][ ppc["branch"][:, T_BUS].astype(int) ].copy()
            if 'areas' in ppc:
                ppc["areas"][:, PRICE_REF_BUS] = \
                    o["bus"]["e2i"][ ppc["areas"][:,
                        PRICE_REF_BUS].astype(int) ].copy()

            ## reorder gens in order of increasing bus number
            o["gen"]["e2i"] = argsort(ppc["gen"][:, GEN_BUS])
            o["gen"]["i2e"] = argsort(o["gen"]["e2i"])

            ppc["gen"] = ppc["gen"][o["gen"]["e2i"].astype(int), :]

            if 'int' in o:
                del o['int']
            o["state"] = 'i'
            ppc["order"] = o

            ## update gencost, A and N
            if 'gencost' in ppc:
                ordering = ['gen']            ## Pg cost only
                if ppc["gencost"].shape[0] == (2 * ng0):
                    ordering.append('gen')    ## include Qg cost
                ppc = e2i_field(ppc, 'gencost', ordering)
            if 'A' in ppc or 'N' in ppc:
                if dc:
                    ordering = ['bus', 'gen']
                else:
                    ordering = ['bus', 'bus', 'gen', 'gen']
            if 'A' in ppc:
                ppc = e2i_field(ppc, 'A', ordering, 1)
            if 'N' in ppc:
                ppc = e2i_field(ppc, 'N', ordering, 1)

            ## execute userfcn callbacks for 'ext2int' stage
            if 'userfcn' in ppc:
                ppc = run_userfcn(ppc['userfcn'], 'ext2int', ppc)
    else:                    ## convert extra data
        if isinstance(val_or_field, str) or isinstance(val_or_field, list):
            ## field
            warn('Calls of the form ppc = ext2int(ppc, '
                '\'field_name\', ...) have been deprecated. Please '
                'replace ext2int with e2i_field.', DeprecationWarning)
            gen, branch = val_or_field, ordering
            ppc = e2i_field(ppc, gen, branch, dim)

        else:
            ## value
            warn('Calls of the form val = ext2int(ppc, val, ...) have been '
                 'deprecated. Please replace ext2int with e2i_data.',
                 DeprecationWarning)
            gen, branch = val_or_field, ordering
            ppc = e2i_data(ppc, gen, branch, dim)

    return ppc


def ext2int1(bus, gen, branch, areas=None):
    """Converts from (possibly non-consecutive) external bus numbers to
    consecutive internal bus numbers which start at 1. Changes are made
    to BUS, GEN, BRANCH and optionally AREAS matrices, which are returned
    along with a vector of indices I2E that can be passed to INT2EXT to
    perform the reverse conversion.

    @see: L{int2ext}
    @see: U{http://www.pserc.cornell.edu/matpower/}
    """
    i2e = bus[:, BUS_I].astype(int)
    e2i = zeros(max(i2e) + 1)
    e2i[i2e] = arange(bus.shape[0])

    bus[:, BUS_I]    = e2i[ bus[:, BUS_I].astype(int)    ]
    gen[:, GEN_BUS]  = e2i[ gen[:, GEN_BUS].astype(int)  ]
    branch[:, F_BUS] = e2i[ branch[:, F_BUS].astype(int) ]
    branch[:, T_BUS] = e2i[ branch[:, T_BUS].astype(int) ]
    if areas is not None and len(areas) > 0:
        areas[:, PRICE_REF_BUS] = e2i[ areas[:, PRICE_REF_BUS].astype(int) ]

        return i2e, bus, gen, branch, areas

    return i2e, bus, gen, branch
