# -*- coding: utf-8 -*-
# Copyright 2014 matrix.org
#
# Licensed 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.

""" This module contains REST servlets to do with rooms: /rooms/<paths> """
from twisted.internet import defer

from base import RestServlet, client_path_pattern
from synapse.api.errors import SynapseError, Codes
from synapse.api.events.room import (
    MessageEvent, RoomMemberEvent, FeedbackEvent
)
from synapse.api.constants import Feedback
from synapse.api.streams import PaginationConfig

import json
import logging
import urllib


logger = logging.getLogger(__name__)


class RoomCreateRestServlet(RestServlet):
    # No PATTERN; we have custom dispatch rules here

    def register(self, http_server):
        # /rooms OR /rooms/<roomid>
        http_server.register_path("POST",
                                  client_path_pattern("/rooms$"),
                                  self.on_POST)
        http_server.register_path("PUT",
                                  client_path_pattern(
                                      "/rooms/(?P<room_id>[^/]*)$"),
                                  self.on_PUT)
        # define CORS for all of /rooms in RoomCreateRestServlet for simplicity
        http_server.register_path("OPTIONS",
                                  client_path_pattern("/rooms(?:/.*)?$"),
                                  self.on_OPTIONS)

    @defer.inlineCallbacks
    def on_PUT(self, request, room_id):
        room_id = urllib.unquote(room_id)
        auth_user = yield self.auth.get_user_by_req(request)

        if not room_id:
            raise SynapseError(400, "PUT must specify a room ID")

        room_config = self.get_room_config(request)
        info = yield self.make_room(room_config, auth_user, room_id)
        room_config.update(info)
        defer.returnValue((200, info))

    @defer.inlineCallbacks
    def on_POST(self, request):
        auth_user = yield self.auth.get_user_by_req(request)

        room_config = self.get_room_config(request)
        info = yield self.make_room(room_config, auth_user, None)
        room_config.update(info)
        defer.returnValue((200, info))

    @defer.inlineCallbacks
    def make_room(self, room_config, auth_user, room_id):
        handler = self.handlers.room_creation_handler
        info = yield handler.create_room(
            user_id=auth_user.to_string(),
            room_id=room_id,
            config=room_config
        )
        defer.returnValue(info)

    def get_room_config(self, request):
        try:
            user_supplied_config = json.loads(request.content.read())
            if "visibility" not in user_supplied_config:
                # default visibility
                user_supplied_config["visibility"] = "public"
            return user_supplied_config
        except (ValueError, TypeError):
            raise SynapseError(400, "Body must be JSON.",
                               errcode=Codes.BAD_JSON)

    def on_OPTIONS(self, request):
        return (200, {})


class RoomStateEventRestServlet(RestServlet):
    def register(self, http_server):
        # /room/$roomid/state/$eventtype
        no_state_key = "/rooms/(?P<room_id>[^/]*)/state/(?P<event_type>[^/]*)$"

        # /room/$roomid/state/$eventtype/$statekey
        state_key = ("/rooms/(?P<room_id>[^/]*)/state/" +
            "(?P<event_type>[^/]*)/(?P<state_key>[^/]*)$")

        http_server.register_path("GET",
                                  client_path_pattern(state_key),
                                  self.on_GET)
        http_server.register_path("PUT",
                                  client_path_pattern(state_key),
                                  self.on_PUT)
        http_server.register_path("GET",
                                  client_path_pattern(no_state_key),
                                  self.on_GET_no_state_key)
        http_server.register_path("PUT",
                                  client_path_pattern(no_state_key),
                                  self.on_PUT_no_state_key)

    def on_GET_no_state_key(self, request, room_id, event_type):
        return self.on_GET(request, room_id, event_type, "")

    def on_PUT_no_state_key(self, request, room_id, event_type):
        return self.on_PUT(request, room_id, event_type, "")

    @defer.inlineCallbacks
    def on_GET(self, request, room_id, event_type, state_key):
        user = yield self.auth.get_user_by_req(request)

        msg_handler = self.handlers.message_handler
        data = yield msg_handler.get_room_data(
            user_id=user.to_string(),
            room_id=urllib.unquote(room_id),
            event_type=urllib.unquote(event_type),
            state_key=urllib.unquote(state_key),
        )

        if not data:
            raise SynapseError(404, "Event not found.", errcode=Codes.NOT_FOUND)
        defer.returnValue((200, data[0].get_dict()["content"]))

    @defer.inlineCallbacks
    def on_PUT(self, request, room_id, event_type, state_key):
        user = yield self.auth.get_user_by_req(request)
        event_type = urllib.unquote(event_type)

        content = _parse_json(request)

        event = self.event_factory.create_event(
            etype=event_type,
            content=content,
            room_id=urllib.unquote(room_id),
            user_id=user.to_string(),
            state_key=urllib.unquote(state_key)
            )
        if event_type == RoomMemberEvent.TYPE:
            # membership events are special
            handler = self.handlers.room_member_handler
            yield handler.change_membership(event)
            defer.returnValue((200, ""))
        else:
            # store random bits of state
            msg_handler = self.handlers.message_handler
            yield msg_handler.store_room_data(
                event=event
            )
            defer.returnValue((200, ""))


class JoinRoomAliasServlet(RestServlet):
    PATTERN = client_path_pattern("/join/(?P<room_alias>[^/]+)$")

    @defer.inlineCallbacks
    def on_PUT(self, request, room_alias):
        user = yield self.auth.get_user_by_req(request)

        if not user:
            defer.returnValue((403, "Unrecognized user"))

        logger.debug("room_alias: %s", room_alias)

        room_alias = self.hs.parse_roomalias(urllib.unquote(room_alias))

        handler = self.handlers.room_member_handler
        ret_dict = yield handler.join_room_alias(user, room_alias)

        defer.returnValue((200, ret_dict))


class MessageRestServlet(RestServlet):
    PATTERN = client_path_pattern("/rooms/(?P<room_id>[^/]*)/messages/"
                                  + "(?P<sender_id>[^/]*)/(?P<msg_id>[^/]*)$")

    def get_event_type(self):
        return MessageEvent.TYPE

    @defer.inlineCallbacks
    def on_GET(self, request, room_id, sender_id, msg_id):
        user = yield self.auth.get_user_by_req(request)

        msg_handler = self.handlers.message_handler
        msg = yield msg_handler.get_message(room_id=urllib.unquote(room_id),
                                            sender_id=urllib.unquote(sender_id),
                                            msg_id=msg_id,
                                            user_id=user.to_string(),
                                            )

        if not msg:
            raise SynapseError(404, "Message not found.",
                               errcode=Codes.NOT_FOUND)

        defer.returnValue((200, json.loads(msg.content)))

    @defer.inlineCallbacks
    def on_PUT(self, request, room_id, sender_id, msg_id):
        user = yield self.auth.get_user_by_req(request)

        if user.to_string() != urllib.unquote(sender_id):
            raise SynapseError(403, "Must send messages as yourself.",
                               errcode=Codes.FORBIDDEN)

        content = _parse_json(request)

        event = self.event_factory.create_event(
            etype=self.get_event_type(),
            room_id=urllib.unquote(room_id),
            user_id=user.to_string(),
            msg_id=msg_id,
            content=content
            )

        msg_handler = self.handlers.message_handler
        yield msg_handler.send_message(event)

        defer.returnValue((200, ""))


class FeedbackRestServlet(RestServlet):
    PATTERN = client_path_pattern(
        "/rooms/(?P<room_id>[^/]*)/messages/" +
        "(?P<msg_sender_id>[^/]*)/(?P<msg_id>[^/]*)/feedback/" +
        "(?P<sender_id>[^/]*)/(?P<feedback_type>[^/]*)$"
    )

    def get_event_type(self):
        return FeedbackEvent.TYPE

    @defer.inlineCallbacks
    def on_GET(self, request, room_id, msg_sender_id, msg_id, fb_sender_id,
               feedback_type):
        user = yield (self.auth.get_user_by_req(request))

        # TODO (erikj): Implement this?
        raise NotImplementedError("Getting feedback is not supported")

#        if feedback_type not in Feedback.LIST:
#            raise SynapseError(400, "Bad feedback type.",
#                               errcode=Codes.BAD_JSON)
#
#        msg_handler = self.handlers.message_handler
#        feedback = yield msg_handler.get_feedback(
#            room_id=urllib.unquote(room_id),
#            msg_sender_id=msg_sender_id,
#            msg_id=msg_id,
#            user_id=user.to_string(),
#            fb_sender_id=fb_sender_id,
#            fb_type=feedback_type
#        )
#
#        if not feedback:
#            raise SynapseError(404, "Feedback not found.",
#                               errcode=Codes.NOT_FOUND)
#
#        defer.returnValue((200, json.loads(feedback.content)))

    @defer.inlineCallbacks
    def on_PUT(self, request, room_id, sender_id, msg_id, fb_sender_id,
               feedback_type):
        user = yield (self.auth.get_user_by_req(request))

        if user.to_string() != fb_sender_id:
            raise SynapseError(403, "Must send feedback as yourself.",
                               errcode=Codes.FORBIDDEN)

        if feedback_type not in Feedback.LIST:
            raise SynapseError(400, "Bad feedback type.",
                               errcode=Codes.BAD_JSON)

        content = _parse_json(request)

        event = self.event_factory.create_event(
            etype=self.get_event_type(),
            room_id=urllib.unquote(room_id),
            msg_sender_id=sender_id,
            msg_id=msg_id,
            user_id=user.to_string(),  # user sending the feedback
            feedback_type=feedback_type,
            content=content
            )

        msg_handler = self.handlers.message_handler
        yield msg_handler.send_feedback(event)

        defer.returnValue((200, ""))


class RoomMemberListRestServlet(RestServlet):
    PATTERN = client_path_pattern("/rooms/(?P<room_id>[^/]*)/members/list$")

    @defer.inlineCallbacks
    def on_GET(self, request, room_id):
        # TODO support Pagination stream API (limit/tokens)
        user = yield self.auth.get_user_by_req(request)
        handler = self.handlers.room_member_handler
        members = yield handler.get_room_members_as_pagination_chunk(
            room_id=urllib.unquote(room_id),
            user_id=user.to_string())

        for event in members["chunk"]:
            # FIXME: should probably be state_key here, not user_id
            target_user = self.hs.parse_userid(event["user_id"])
            # Presence is an optional cache; don't fail if we can't fetch it
            try:
                presence_state = yield self.handlers.presence_handler.get_state(
                    target_user=target_user, auth_user=user
                )
                event["content"].update(presence_state)
            except:
                pass

        defer.returnValue((200, members))


class RoomMessageListRestServlet(RestServlet):
    PATTERN = client_path_pattern("/rooms/(?P<room_id>[^/]*)/messages/list$")

    @defer.inlineCallbacks
    def on_GET(self, request, room_id):
        user = yield self.auth.get_user_by_req(request)
        pagination_config = PaginationConfig.from_request(request)
        with_feedback = "feedback" in request.args
        handler = self.handlers.message_handler
        msgs = yield handler.get_messages(
            room_id=urllib.unquote(room_id),
            user_id=user.to_string(),
            pagin_config=pagination_config,
            feedback=with_feedback)

        defer.returnValue((200, msgs))


class RoomTriggerBackfill(RestServlet):
    PATTERN = client_path_pattern("/rooms/(?P<room_id>[^/]*)/backfill$")

    @defer.inlineCallbacks
    def on_GET(self, request, room_id):
        remote_server = urllib.unquote(request.args["remote"][0])
        room_id = urllib.unquote(room_id)
        limit = int(request.args["limit"][0])

        handler = self.handlers.federation_handler
        events = yield handler.backfill(remote_server, room_id, limit)

        res = [event.get_dict() for event in events]
        defer.returnValue((200, res))


class RoomMembershipRestServlet(RestServlet):

    def register(self, http_server):
        # /rooms/$roomid/[invite|join|leave]
        PATTERN = ("/rooms/(?P<room_id>[^/]*)/" +
            "(?P<membership_action>join|invite|leave)")
        register_txn_path(self, PATTERN, http_server)

    def on_POST(self, request, room_id, membership_action):
        return (200, "Not implemented")

    def on_PUT(self, request, room_id, membership_action, txn_id):
        return (200, "Not implemented")


def _parse_json(request):
    try:
        content = json.loads(request.content.read())
        if type(content) != dict:
            raise SynapseError(400, "Content must be a JSON object.",
                               errcode=Codes.NOT_JSON)
        return content
    except ValueError:
        raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)


def register_txn_path(servlet, regex_string, http_server):
    """Registers a transaction-based path.

    This registers two paths:
        PUT regex_string/$txnid
        POST regex_string

    Args:
        regex_string (str): The regex string to register. Must NOT have a
        trailing $ as this string will be appended to.
        http_server : The http_server to register paths with.
    """
    http_server.register_path(
        "POST",
        client_path_pattern(regex_string + "$"),
        servlet.on_POST
    )
    http_server.register_path(
        "PUT",
        client_path_pattern(regex_string + "/(?P<txn_id>[^/]*)$"),
        servlet.on_PUT
    )


def register_servlets(hs, http_server):
    RoomStateEventRestServlet(hs).register(http_server)
    MessageRestServlet(hs).register(http_server)
    FeedbackRestServlet(hs).register(http_server)
    RoomCreateRestServlet(hs).register(http_server)
    RoomMemberListRestServlet(hs).register(http_server)
    RoomMessageListRestServlet(hs).register(http_server)
    JoinRoomAliasServlet(hs).register(http_server)
    RoomTriggerBackfill(hs).register(http_server)
    RoomMembershipRestServlet(hs).register(http_server)