text: #       Licensed to the Apache Software Foundation (ASF) under one
  #       or more contributor license agreements.  See the NOTICE file
  #       distributed with this work for additional information
  #       regarding copyright ownership.  The ASF licenses this file
  #       to you under the Apache License, Version 2.0 (the
  #       "License"); you may not use this file except in compliance
  #       with the License.  You may obtain a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #       Unless required by applicable law or agreed to in writing,
  #       software distributed under the License is distributed on an
  #       "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  #       KIND, either express or implied.  See the License for the
  #       specific language governing permissions and limitations
  #       under the License.
  
  from __future__ import unicode_literals
  from __future__ import absolute_import
  import logging
  import json
  import hmac
  import hashlib
  import time
  import socket
  import ssl
  
  from bson import ObjectId
  from tg import expose, validate, redirect, flash, config
  from tg.decorators import with_trailing_slash, without_trailing_slash
  from tg import tmpl_context as c
  from tg import response, request
  from formencode import validators as fev, schema, Invalid
  from ming.odm import session
  from webob import exc
  from pymongo.errors import DuplicateKeyError
  from paste.deploy.converters import asint, aslist
  
  from allura.app import AdminControllerMixin
  from allura.controllers import BaseController
  from allura.lib import helpers as h
  import requests
  from allura.lib import validators as v
  from allura.lib.decorators import require_post, task
  from allura.lib.utils import DateJSONEncoder
  from allura import model as M
  import six
  from six.moves import map
  
  
  log = logging.getLogger(__name__)
  
  
  class WebhookValidator(fev.FancyValidator):
      def __init__(self, sender, app, **kw):
          self.app = app
          self.sender = sender
          super(WebhookValidator, self).__init__(**kw)
  
      def _to_python(self, value, state):
          wh = None
          if isinstance(value, M.Webhook):
              wh = value
          elif isinstance(value, ObjectId):
              wh = M.Webhook.query.get(_id=value)
          else:
              try:
                  wh = M.Webhook.query.get(_id=ObjectId(value))
              except Exception:
                  pass
          if wh and wh.type == self.sender.type and wh.app_config_id == self.app.config._id:
              return wh
          raise Invalid('Invalid webhook', value, state)
  
  
  class WebhookCreateForm(schema.Schema):
      url = fev.URL(not_empty=True)
      secret = v.UnicodeString()
  
  
  class WebhookEditForm(WebhookCreateForm):
      def __init__(self, sender, app):
          super(WebhookEditForm, self).__init__()
          self.add_field('webhook', WebhookValidator(
              sender=sender, app=app, not_empty=True))
  
  
  class WebhookControllerMeta(type):
      def __call__(cls, sender, app, *args, **kw):
          """Decorate post handlers with a validator that references
          the appropriate webhook sender for this controller.
          """
          if hasattr(cls, 'create'):
              cls.create = validate(
                  cls.create_form(),
                  error_handler=getattr(cls.index, '__func__', cls.index),
              )(cls.create)
          if hasattr(cls, 'edit'):
              cls.edit = validate(
                  cls.edit_form(sender, app),
                  error_handler=getattr(cls._default, '__func__', cls._default),
              )(cls.edit)
          return type.__call__(cls, sender, app, *args, **kw)
  
  
  class WebhookController(six.with_metaclass(WebhookControllerMeta, BaseController, AdminControllerMixin)):
      create_form = WebhookCreateForm
      edit_form = WebhookEditForm
  
      def __init__(self, sender, app):
          super(WebhookController, self).__init__()
          self.sender = sender()
          self.app = app
  
      def gen_secret(self):
          return h.cryptographic_nonce(20)
  
      def update_webhook(self, wh, url, secret=None):
          if not secret:
              secret = self.gen_secret()
          wh.hook_url = url
          wh.secret = secret
          try:
              session(wh).flush(wh)
          except DuplicateKeyError:
              session(wh).expunge(wh)
              msg = '_the_form: "{}" webhook already exists for {} {}'.format(
                  wh.type, self.app.config.options.mount_label, url)
              raise Invalid(msg, None, None)
  
      @with_trailing_slash
      @expose('jinja:allura:templates/webhooks/create_form.html')
      def index(self, **kw):
          if not c.form_values and kw:
              # Executes if update_webhook raises an error
              c.form_values = {'url': kw.get('url'),
                               'secret': kw.get('secret')}
          return {'sender': self.sender,
                  'action': 'create',
                  'form': self.create_form()}
  
      @expose('jinja:allura:templates/webhooks/create_form.html')  # needed when we "return self.index(...)"
      @require_post()
      # @validate set dynamically in WebhookControllerMeta
      def create(self, url, secret):
          if self.sender.enforce_limit(self.app):
              webhook = M.Webhook(
                  type=self.sender.type,
                  app_config_id=self.app.config._id)
              try:
                  self.update_webhook(webhook, url, secret)
              except Invalid as e:
                  # trigger error_handler directly
                  c.form_errors['_the_form'] = e
                  return self.index(url=url, secret=secret)
  
              M.AuditLog.log('add webhook %s %s %s',
                             webhook.type, webhook.hook_url,
                             webhook.app_config.url())
              flash('Created successfully', 'ok')
          else:
              flash('You have exceeded the maximum number of webhooks '
                    'you are allowed to create for this project/app', 'error')
          redirect(self.app.admin_url + 'webhooks')
  
      @expose('jinja:allura:templates/webhooks/create_form.html')  # needed when we "return self._default(...)"
      @require_post()
      # @validate set dynamically in WebhookControllerMeta
      def edit(self, webhook, url, secret):
          old_url = webhook.hook_url
          old_secret = webhook.secret
          try:
              self.update_webhook(webhook, url, secret)
          except Invalid as e:
              # trigger error_handler directly
              c.form_errors['_the_form'] = e
              return self._default(webhook=webhook, url=url, secret=secret)
          M.AuditLog.log('edit webhook %s\n%s => %s\n%s',
                         webhook.type, old_url, url,
                         'secret changed' if old_secret != secret else '')
          flash('Edited successfully', 'ok')
          redirect(self.app.admin_url + 'webhooks')
  
      @expose('json:')
      @require_post()
      def delete(self, webhook, **kw):
          form = self.edit_form(self.sender, self.app)
          try:
              wh = form.fields['webhook'].to_python(webhook)
          except Invalid:
              raise exc.HTTPNotFound()
          wh.delete()
          M.AuditLog.log('delete webhook %s %s %s',
                         wh.type, wh.hook_url, wh.app_config.url())
          return {'status': 'ok'}
  
      @without_trailing_slash
      @expose('jinja:allura:templates/webhooks/create_form.html')
      def _default(self, webhook, **kw):
          form = self.edit_form(self.sender, self.app)
          try:
              wh = form.fields['webhook'].to_python(webhook)
          except Invalid:
              raise exc.HTTPNotFound()
          c.form_values = {'url': kw.get('url') or wh.hook_url,
                           'secret': kw.get('secret') or wh.secret,
                           'webhook': six.text_type(wh._id)}
          return {'sender': self.sender,
                  'action': 'edit',
                  'form': form}
  
  
  class WebhookRestController(BaseController):
      def __init__(self, sender, app):
          super(WebhookRestController, self).__init__()
          self.sender = sender()
          self.app = app
          self.create_form = WebhookController.create_form
          self.edit_form = WebhookController.edit_form
  
      def _error(self, e):
          error = getattr(e, 'error_dict', None)
          if error:
              _error = {}
              for k, val in six.iteritems(error):
                  _error[k] = six.text_type(val)
              return _error
          error = getattr(e, 'msg', None)
          if not error:
              error = getattr(e, 'message', '')
          return error
  
      def update_webhook(self, wh, url, secret=None):
          controller = WebhookController(self.sender.__class__, self.app)
          controller.update_webhook(wh, url, secret)
  
      @expose('json:')
      @require_post()
      def index(self, **kw):
          response.content_type = str('application/json')
          try:
              params = {'secret': kw.pop('secret', ''),
                        'url': kw.pop('url', None)}
              valid = self.create_form().to_python(params)
          except Exception as e:
              response.status_int = 400
              return {'result': 'error', 'error': self._error(e)}
          if self.sender.enforce_limit(self.app):
              webhook = M.Webhook(
                  type=self.sender.type,
                  app_config_id=self.app.config._id)
              try:
                  self.update_webhook(webhook, valid['url'], valid['secret'])
              except Invalid as e:
                  response.status_int = 400
                  return {'result': 'error', 'error': self._error(e)}
              M.AuditLog.log('add webhook %s %s %s',
                             webhook.type, webhook.hook_url,
                             webhook.app_config.url())
              response.status_int = 201
              # refetch updated values (e.g. mod_date)
              session(webhook).expunge(webhook)
              webhook = M.Webhook.query.get(_id=webhook._id)
              return webhook.__json__()
          else:
              limits = {
                  'max': M.Webhook.max_hooks(
                      self.sender.type,
                      self.app.config.tool_name),
                  'used': M.Webhook.query.find({
                      'type': self.sender.type,
                      'app_config_id': self.app.config._id,
                  }).count(),
              }
              resp = {
                  'result': 'error',
                  'error': 'You have exceeded the maximum number of webhooks '
                           'you are allowed to create for this project/app',
                  'limits': limits,
              }
              response.status_int = 400
              return resp
  
      @expose('json:')
      def _default(self, webhook, **kw):
          form = self.edit_form(self.sender, self.app)
          try:
              wh = form.fields['webhook'].to_python(webhook)
          except Invalid:
              raise exc.HTTPNotFound()
          if request.method == 'POST':
              return self._edit(wh, form, **kw)
          elif request.method == 'DELETE':
              return self._delete(wh)
          else:
              return wh.__json__()
  
      def _edit(self, webhook, form, **kw):
          old_secret = webhook.secret
          old_url = webhook.hook_url
          try:
              params = {'secret': kw.pop('secret', old_secret),
                        'url': kw.pop('url', old_url),
                        'webhook': six.text_type(webhook._id)}
              valid = form.to_python(params)
          except Exception as e:
              response.status_int = 400
              return {'result': 'error', 'error': self._error(e)}
          try:
              self.update_webhook(webhook, valid['url'], valid['secret'])
          except Invalid as e:
              response.status_int = 400
              return {'result': 'error', 'error': self._error(e)}
          M.AuditLog.log(
              'edit webhook %s\n%s => %s\n%s',
              webhook.type, old_url, valid['url'],
              'secret changed' if old_secret != valid['secret'] else '')
          # refetch updated values (e.g. mod_date)
          session(webhook).expunge(webhook)
          webhook = M.Webhook.query.get(_id=webhook._id)
          return webhook.__json__()
  
      def _delete(self, webhook):
          webhook.delete()
          M.AuditLog.log(
              'delete webhook %s %s %s',
              webhook.type,
              webhook.hook_url,
              webhook.app_config.url())
          return {'result': 'ok'}
  
  
  class SendWebhookHelper(object):
      def __init__(self, webhook, payload):
          self.webhook = webhook
          self.payload = payload
  
      @property
      def timeout(self):
          return asint(config.get('webhook.timeout', 30))
  
      @property
      def retries(self):
          t = aslist(config.get('webhook.retry', [60, 120, 240]))
          return list(map(int, t))
  
      def sign(self, json_payload):
          signature = hmac.new(
              self.webhook.secret.encode('utf-8'),
              json_payload.encode('utf-8'),
              hashlib.sha1)
          return 'sha1=' + signature.hexdigest()
  
      def log_msg(self, msg, response=None):
          message = '{}: {} {} {}'.format(
              msg,
              self.webhook.type,
              self.webhook.hook_url,
              self.webhook.app_config.url())
          if response is not None:
              message = '{} {} {} {}'.format(
                  message,
                  response.status_code,
                  response.text,
                  response.headers)
          return message
  
      def send(self):
          json_payload = json.dumps(self.payload, cls=DateJSONEncoder)
          signature = self.sign(json_payload)
          headers = {'content-type': 'application/json',
                     'User-Agent': 'Allura Webhook (https://allura.apache.org/)',
                     'X-Allura-Signature': signature}
          ok = self._send(self.webhook.hook_url, json_payload, headers)
          if not ok:
              log.info('Retrying webhook in: %s', self.retries)
              for t in self.retries:
                  log.info('Retrying webhook in %s seconds', t)
                  time.sleep(t)
                  ok = self._send(self.webhook.hook_url, json_payload, headers)
                  if ok:
                      return
  
      def _send(self, url, data, headers):
          try:
              r = requests.post(
                  url,
                  data=data,
                  headers=headers,
                  timeout=self.timeout)
          except (requests.exceptions.RequestException,
                  socket.timeout,
                  ssl.SSLError):
              log.exception(self.log_msg('Webhook send error'))
              return False
          if r.status_code >= 200 and r.status_code < 300:
              log.info(self.log_msg('Webhook successfully sent'))
              return True
          else:
              log.error(self.log_msg('Webhook send error', response=r))
              return False
  
  
  @task()
  def send_webhook(webhook_id, payload):
      webhook = M.Webhook.query.get(_id=webhook_id)
      SendWebhookHelper(webhook, payload).send()
  
  
  class WebhookSender(object):
      """Base class for webhook senders.
  
      Subclasses are required to implement :meth:`get_payload()` and set
      :attr:`type` and :attr:`triggered_by`.
      """
  
      type = None
      triggered_by = []
      controller = WebhookController
      api_controller = WebhookRestController
  
      def get_payload(self, **kw):
          """Return a dict with webhook payload"""
          raise NotImplementedError('get_payload')
  
      def send(self, params_or_list):
          """Post a task that will send webhook payload
  
          :param params_or_list: dict with keyword parameters to be passed to
              :meth:`get_payload` or a list of such dicts. If it's a list for each
              element appropriate payload will be submitted, but limit will be
              enforced only once for each webhook.
          """
          if not isinstance(params_or_list, list):
              params_or_list = [params_or_list]
          webhooks = M.Webhook.query.find(dict(
              app_config_id=c.app.config._id,
              type=self.type,
          )).all()
          if webhooks:
              payloads = [self.get_payload(**params)
                          for params in params_or_list]
              for webhook in webhooks:
                  if webhook.enforce_limit():
                      webhook.update_limit()
                      for payload in payloads:
                          send_webhook.post(webhook._id, payload)
                  else:
                      log.warn('Webhook fires too often: %s. Skipping', webhook)
  
      def enforce_limit(self, app):
          '''
          Checks if limit of webhooks created for given project/app is reached.
          Returns False if limit is reached, True otherwise.
          '''
          count = M.Webhook.query.find(dict(
              app_config_id=app.config._id,
              type=self.type,
          )).count()
          limit = M.Webhook.max_hooks(self.type, app.config.tool_name)
          return count < limit
  
  
  class RepoPushWebhookSender(WebhookSender):
      type = 'repo-push'
      triggered_by = ['git', 'hg', 'svn']
  
      def _before(self, repo, commit_ids):
          if len(commit_ids) > 0:
              ci = commit_ids[-1]
              parents = repo.commit(ci).parent_ids
              if len(parents) > 0:
                  # Merge commit will have multiple parents. As far as I can tell
                  # the last one will be the branch head before merge
                  return self._convert_id(parents[-1])
          return ''
  
      def _after(self, commit_ids):
          if len(commit_ids) > 0:
              return self._convert_id(commit_ids[0])
          return ''
  
      def _convert_id(self, _id):
          if ':' in _id:
              _id = 'r' + _id.rsplit(':', 1)[1]
          return _id
  
      def get_payload(self, commit_ids, **kw):
          app = kw.get('app') or c.app
          commits = [app.repo.commit(ci).webhook_info for ci in commit_ids]
          for ci in commits:
              ci['id'] = self._convert_id(ci['id'])
          before = self._before(app.repo, commit_ids)
          after = self._after(commit_ids)
          payload = {
              'size': len(commits),
              'commits': commits,
              'before': before,
              'after': after,
              'repository': {
                  'name': app.config.options.mount_label,
                  'full_name': app.url,
                  'url': h.absurl(app.url),
              },
          }
          if kw.get('ref'):
              payload['ref'] = kw['ref']
          return payload
  