# -*- coding: utf-8 -*-

'''

Created on Jul 01, 2014

@author: tc

'''

from datetime import datetime

import json

import logging

import uuid

from django.core.urlresolvers import reverse

from django.http import Http404

from django.http.response import HttpResponse, HttpResponseBadRequest

from django.shortcuts import get_object_or_404, redirect

from django.views.decorators.csrf import csrf_exempt

from django.views.generic import View

from renkanmanager.models import Renkan, Revision, Workspace

from renkanmanager.permissions import CanEditRenkan, CanDeleteRenkan, CanCreateRenkan, \

                                      CanEditWorkspace, CanDeleteWorkspace, CanCreateWorkspace, \

                                      CanDeleteRevision

from renkanmanager.serializers import RenkanSerializer, RevisionSerializer, WorkspaceSerializer

from rest_framework import permissions, status

from rest_framework.response import Response

from rest_framework.views import APIView

logger = logging.getLogger(__name__)

class RenkanList(APIView):

    """

        View for listing renkans or posting new renkan

    """

    permission_classes = (

        permissions.IsAuthenticatedOrReadOnly,

        CanCreateRenkan,

    )

    def get(self, request, workspace_guid='', format=None):

        if workspace_guid == '':

            renkans = Renkan.objects.all()

        else:

            renkans = Renkan.objects.filter(workspace_guid=workspace_guid)

        serializer = RenkanSerializer(renkans, many=True)

    def post(self, request, workspace_guid='', format=None):

        create_data = request.data

        # We check if the POST request is a copy request, either with ?source="id" query arg or with source_revision_guid present in the data

        if source_revision_guid is not None:

            try:

                source_revision=Revision.objects.get(revision_guid=source_revision_guid)

            except Revision.DoesNotExist:

                return Response({'detail': 'Source revision '+source_revision_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

            create_data["source_revision_guid"] = source_revision.revision_guid

            create_data["content"] = source_revision.content

        if workspace_guid:

            try:

                workspace = Workspace.objects.get(workspace_guid=workspace_guid)

            except Workspace.DoesNotExist:

                return Response({'detail': 'Workspace '+workspace_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

            create_data["workspace_guid"] = workspace_guid

        serializer = RenkanSerializer(data=create_data)

        if serializer.is_valid():

            serializer.save(creator=request.user)       

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

class RenkanDetail(APIView):

    """

        View for retrieving, updating or deleting a single renkan

    """

    lookup_field = "renkan_guid"

    permission_classes = (

        permissions.IsAuthenticatedOrReadOnly, 

        CanEditRenkan,

        CanDeleteRenkan,

    )

    def get_object(self, renkan_guid):

        return Renkan.objects.get(renkan_guid=renkan_guid)

    def get(self, request, renkan_guid, format=None):

        try:

            renkan = self.get_object(renkan_guid=renkan_guid)

        except Renkan.DoesNotExist:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, renkan)

        serializer = RenkanSerializer(renkan)

    def put(self, request, renkan_guid, format=None):

        try:

            renkan = self.get_object(renkan_guid=renkan_guid)

        except Renkan.DoesNotExist:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, renkan)

        if serializer.is_valid():

            serializer.save(updator=request.user)

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

    def delete(self, request, renkan_guid, format=None):

        try:

            to_delete_renkan = self.get_object(renkan_guid=renkan_guid)

        except Renkan.DoesNotExist:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, to_delete_renkan)

        renkan_revisions = Revision.objects.filter(parent_renkan_guid = to_delete_renkan.renkan_guid)

        for child_revision in renkan_revisions:

            # Deleting reference to revision in renkans copied from this revision

            for related_renkan in Renkan.objects.filter(source_revision_guid=child_revision.revision_guid):

                related_renkan.source_revision_guid = ''

                related_renkan.save()

            child_revision.delete()

        to_delete_renkan.delete()

        return Response(status=status.HTTP_204_NO_CONTENT)

class WorkspaceList(APIView):

    """

        View for listing workspaces or creating new workspace

    """

    permission_classes = (

        permissions.IsAuthenticatedOrReadOnly,

        CanCreateWorkspace,

    )

    def get(self, request, format=None):

        workspaces = Workspace.objects.all()

        serializer = WorkspaceSerializer(workspaces, many=True)

        return Response(serializer.data)

    def post(self, request, format=None):

        serializer = WorkspaceSerializer(data=request.data)

        if serializer.is_valid():

            serializer.save(creator=request.user)       

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

class WorkspaceDetail(APIView):

    """

        View for retrieving, updating or deleting a single workspace

    """

    permission_classes = (

        permissions.IsAuthenticatedOrReadOnly,

        CanEditWorkspace,

        CanDeleteWorkspace,

    )

    def get_object(self, workspace_guid):

        return Workspace.objects.get(workspace_guid=workspace_guid)

    def get(self, request, workspace_guid, format=None):

        try:

            workspace = Workspace.objects.get(workspace_guid=workspace_guid)

        except Workspace.DoesNotExist:

            return Response({'detail': 'Workspace '+workspace_guid+' does not exist.'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, workspace)

        serializer = WorkspaceSerializer(workspace)

    def put(self, request, workspace_guid, format=None):

        try:

            workspace = Workspace.objects.get(workspace_guid=workspace_guid)

        except Workspace.DoesNotExist:

            return Response({'detail': 'Workspace '+workspace_guid+' does not exist.'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, workspace)

        serializer = WorkspaceSerializer(workspace, data=request.data)

        if serializer.is_valid():

            serializer.save()       

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

    def delete(self, request, workspace_guid, format=None):

        try:

            to_delete_workspace = self.get_object(workspace_guid=workspace_guid)

        except Workspace.DoesNotExist:

            return Response({'detail': 'Workspace '+workspace_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, to_delete_workspace)

        if to_delete_workspace.renkan_count != 0:

            return Response({'detail': 'Workspace '+workspace_guid+' cannot be deleted because it is not empty'}, status=status.HTTP_400_BAD_REQUEST)

        to_delete_workspace.delete()

        return Response(status=status.HTTP_204_NO_CONTENT)

class RevisionList(APIView):

    """

        View for listing revisions from a given renkan

    """

    permission_classes = (permissions.IsAuthenticatedOrReadOnly,)

    def get_queryset(self, renkan_guid):

        return Revision.objects.filter(parent_renkan_guid=renkan_guid)

    def get(self, request, renkan_guid, format=None):

        revisions = self.get_queryset(renkan_guid)

        if not revisions:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        serializer = RevisionSerializer(revisions.all(), many=True)

class RevisionDetail(APIView):

    """

        View for retrieving or deleting a single revision from a given renkan

    """

    permission_classes = (

        permissions.IsAuthenticatedOrReadOnly,

        CanDeleteRevision,

    )

    def get_queryset(self, renkan_guid):

        return Revision.objects.filter(parent_renkan_guid=renkan_guid)

    def get(self, request, renkan_guid, revision_guid, format=None):

        revisions = self.get_queryset(renkan_guid)

        if not revisions:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        try:

            revision = revisions.get(revision_guid=revision_guid)

        except Revision.DoesNotExist:

            return Response({'detail': 'Revision '+revision_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, revision)

        serializer = RevisionSerializer(revision)

    def delete(self, request, renkan_guid, revision_guid, format=None):

        revisions = self.get_queryset(renkan_guid)

        if not revisions:

            return Response({'detail': 'Renkan project '+renkan_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        try:

            revision = revisions.get(revision_guid=revision_guid)

        except Revision.DoesNotExist:

            return Response({'detail': 'Revision '+revision_guid+' does not exist'}, status=status.HTTP_404_NOT_FOUND)

        self.check_object_permissions(request, revision)

        if revisions.count() == 1:

            return Response({'detail': 'You cannot delete the last remaining revision of a renkan from the Revision API. Try deleting the parent Renkan with the Renkan API'}, status=status.HTTP_400_BAD_REQUEST)

        if revision.is_current_revision:

            return Response({'detail': 'You cannot delete the current revision of a renkan from the Revision API.'}, status=status.HTTP_400_BAD_REQUEST)

        # Deleting reference to revision in renkans copied from this revision

        for related_renkan in Renkan.objects.filter(source_revision_guid=revision_guid):

            related_renkan.source_revision_guid = ''

            related_renkan.save()

        revision.delete()

        return Response(status=status.HTTP_204_NO_CONTENT)