text: # -*- coding: utf-8 -*-
  
  """ S3 Synchronization: Peer Repository Adapter for FTP
  
      @copyright: 2015-2016 (c) Sahana Software Foundation
      @license: MIT
  
      Permission is hereby granted, free of charge, to any person
      obtaining a copy of this software and associated documentation
      files (the "Software"), to deal in the Software without
      restriction, including without limitation the rights to use,
      copy, modify, merge, publish, distribute, sublicense, and/or sell
      copies of the Software, and to permit persons to whom the
      Software is furnished to do so, subject to the following
      conditions:
  
      The above copyright notice and this permission notice shall be
      included in all copies or substantial portions of the Software.
  
      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
      OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
      HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
      WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
      FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
      OTHER DEALINGS IN THE SOFTWARE.
  """
  
  import sys
  
  from gluon import *
  
  from ..s3sync import S3SyncBaseAdapter
  
  from ..s3query import S3URLQuery, FS
  from ..s3rest import S3Request
  from ..s3export import S3Exporter
  
  try:
      from cStringIO import StringIO    # Faster, where available
  except:
      from StringIO import StringIO
  
  # =============================================================================
  class S3SyncAdapter(S3SyncBaseAdapter):
      """
          FTP Synchronization Adapter
  
           currently used by CAP
      """
  
      # -------------------------------------------------------------------------
      def register(self):
          """
              Register this site at the peer repository
  
              @return: True to indicate success, otherwise False
          """
  
          # No registration required
          return True
  
      # -------------------------------------------------------------------------
      def login(self):
          """
              Login at the peer repository
  
              @return: None if successful, otherwise the error
          """
  
          repository = self.repository
          url = repository.url
          error = None
  
          if not url:
              error = "Remote URL required for FTP Push"
          else:
              import ftplib
              try:
                  ftp_connection = ftplib.FTP(url)
              except ftplib.all_errors:
                  error = sys.exc_info()[1]
              else:
                  try:
                      ftp_connection.login(repository.username, repository.password)
                  except ftplib.error_perm:
                      error = sys.exc_info()[1]
  
              self.ftp_connection = ftp_connection
  
          if error:
              current.log.debug(error)
          return error
  
      # -------------------------------------------------------------------------
      def pull(self, task, onconflict=None):
          """
              Fetch updates from the repository and import them
              into the local database (Active Pull)
  
              @param task: the task (sync_task Row)
          """
  
          repository = self.repository
  
          # Log the operation
          message = "Pull from FTP currently not supported"
          log = repository.log
          log.write(repository_id = repository.id,
                    resource_name = task.resource_name,
                    transmission = log.OUT,
                    mode = log.PULL,
                    action = None,
                    remote = False,
                    result = log.FATAL,
                    message = message,
                    )
  
          return message, None
  
      # -------------------------------------------------------------------------
      def push(self, task):
          """
              Extract new updates from the local database and send
              them to the peer repository (active push)
  
              @param task: the synchronization task (sync_task Row)
  
              @return: tuple (error, mtime), with error=None if successful,
                       else error=message, and mtime=modification timestamp
                       of the youngest record sent
          """
  
          repository = self.repository
          resource_name = task.resource_name
          log = repository.log
          remote = False
          output = None
  
          current.log.debug("S3SyncRepository.push(%s, %s)" % (repository.url,
                                                               resource_name))
  
          # Define the resource
          resource = current.s3db.resource(resource_name,
                                           # FTP remote deletion is not supported yet
                                           #include_deleted=True,
                                           )
  
          # Apply sync filters for this task
          filters = current.sync.get_filters(task.id)
          table = resource.table
          tablename = resource.tablename
  
          if filters:
              queries = S3URLQuery.parse(resource, filters[tablename])
              [resource.add_filter(q) for a in queries for q in queries[a]]
  
          # Filter to records after last push
          msince = task.last_push
  
          if msince:
              strategy = task.strategy
              created = "create" in strategy
              updated = "update" in strategy
              if created and updated:
                  mtime_filter = table.modified_on > msince
              elif created:
                  mtime_filter = table.created_on > msince
              elif updated:
                  mtime_filter = (table.created_on <= msince) & \
                                 (table.modified_on > msince)
              else:
                  mtime_filter = None
  
              if mtime_filter:
                  resource.add_filter(mtime_filter)
  
          mtime = resource.muntil
          # Get the ID of the resource after filter and msince
          resource_ids = resource.get_id()
  
          # No Changes since last push?
          if resource_ids is None:
              message = "No Changes since last push"
              result = log.WARNING
          else:
              # Filename
              settings = current.deployment_settings
              # Placeholders for filename
              placeholders = {"systemname": settings.get_system_name(),
                              "systemname_short": settings.get_system_name_short(),
                              "resource": resource_name,
                              "public_url": settings.get_base_public_url(),
                              }
  
              from string import Template
              filename = resource.get_config("upload_filename")
              if not filename:
                  filename = settings.get_sync_upload_filename()
              filename = Template(filename).safe_substitute(s="%(systemname_short)s",
                                                            r="%(resource)s")
              filename = filename % placeholders
              # Get Representation
              representation = task.representation
              filename = ("%s.%s") % (filename, representation)
  
              # FTP Transfer
              remote = True
              import ftplib
              ftp_connection = self.ftp_connection
              if task.multiple_file:
                  if type(resource_ids) is not list:
                      resource_ids = [resource_ids]
  
                  for resource_id in resource_ids:
                      resource.clear_query()
                      resource.add_filter(FS("id") == resource_id)
                      data = self._get_data(resource, representation)
  
                      try:
                          ftp_connection.storbinary("STOR %s" % filename,
                                                    StringIO(data))
                      except ftplib.error_perm:
                          message = sys.exc_info()[1]
                          result = log.ERROR
                          output = message
                      else:
                          message = "FTP Transfer Successful"
                          result = log.SUCCESS
  
                      current.log.debug(message)
              else:
                  data = self._get_data(resource, representation)
  
                  try:
                      ftp_connection.storbinary("STOR %s" % filename,
                                                StringIO(data))
                  except ftplib.error_perm:
                      message = sys.exc_info()[1]
                      result = log.ERROR
                      output = message
                  else:
                      message = "FTP Transfer Successful"
                      result = log.SUCCESS
  
                  current.log.debug(message)
  
              # Quit the connection here
              ftp_connection.quit()
  
          # Log the operation
          log.write(repository_id = repository.id,
                    resource_name = resource_name,
                    transmission = log.OUT,
                    mode = log.PUSH,
                    action = "send",
                    remote = remote,
                    result = result,
                    message = message,
                    )
          # Returns after operation is complete
          if output is not None:
              mtime = None
          return output, mtime
  
      # -------------------------------------------------------------------------
      # Internal methods:
      # -------------------------------------------------------------------------
      def _get_data(self, resource, representation):
          """ Returns the representation data for the resource """
  
          request = S3Request(prefix = resource.prefix,
                              name = resource.name,
                              extension = representation,
                              )
  
          if request.transformable():
              return resource.export_xml(stylesheet = request.stylesheet(),
                                         pretty_print = True,
                                         )
  
          else:
              if representation == "csv":
                  exporter = S3Exporter().csv
  
              # @ToDo use CRUD
              #elif representation == "html":
  
              elif representation == "pdf":
                  exporter = S3Exporter().pdf
  
              elif representation == "xls":
                  exporter = S3Exporter().xls
  
              elif representation == "json":
                  exporter = S3Exporter().json
  
              return exporter(resource)
  
  # End =========================================================================
  