# Copyright 2016 OpenMarket Ltd
#
# 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.


import pydot
import cgi
import simplejson as json
import datetime
import argparse

from synapse.events import FrozenEvent
from synapse.util.frozenutils import unfreeze


def make_graph(file_name, room_id, file_prefix, limit):
    print "Reading lines"
    with open(file_name) as f:
        lines = f.readlines()

    print "Read lines"

    events = [FrozenEvent(json.loads(line)) for line in lines]

    print "Loaded events."

    events.sort(key=lambda e: e.depth)

    print "Sorted events"

    if limit:
        events = events[-int(limit):]

    node_map = {}

    graph = pydot.Dot(graph_name="Test")

    for event in events:
        t = datetime.datetime.fromtimestamp(
            float(event.origin_server_ts) / 1000
        ).strftime('%Y-%m-%d %H:%M:%S,%f')

        content = json.dumps(unfreeze(event.get_dict()["content"]), indent=4)
        content = content.replace("\n", "<br/>\n")

        print content
        content = []
        for key, value in unfreeze(event.get_dict()["content"]).items():
            if value is None:
                value = "<null>"
            elif isinstance(value, basestring):
                pass
            else:
                value = json.dumps(value)

            content.append(
                "<b>%s</b>: %s," % (
                    cgi.escape(key, quote=True).encode("ascii", 'xmlcharrefreplace'),
                    cgi.escape(value, quote=True).encode("ascii", 'xmlcharrefreplace'),
                )
            )

        content = "<br/>\n".join(content)

        print content

        label = (
            "<"
            "<b>%(name)s </b><br/>"
            "Type: <b>%(type)s </b><br/>"
            "State key: <b>%(state_key)s </b><br/>"
            "Content: <b>%(content)s </b><br/>"
            "Time: <b>%(time)s </b><br/>"
            "Depth: <b>%(depth)s </b><br/>"
            ">"
        ) % {
            "name": event.event_id,
            "type": event.type,
            "state_key": event.get("state_key", None),
            "content": content,
            "time": t,
            "depth": event.depth,
        }

        node = pydot.Node(
            name=event.event_id,
            label=label,
        )

        node_map[event.event_id] = node
        graph.add_node(node)

    print "Created Nodes"

    for event in events:
        for prev_id, _ in event.prev_events:
            try:
                end_node = node_map[prev_id]
            except:
                end_node = pydot.Node(
                    name=prev_id,
                    label="<<b>%s</b>>" % (prev_id,),
                )

                node_map[prev_id] = end_node
                graph.add_node(end_node)

            edge = pydot.Edge(node_map[event.event_id], end_node)
            graph.add_edge(edge)

    print "Created edges"

    graph.write('%s.dot' % file_prefix, format='raw', prog='dot')

    print "Created Dot"

    graph.write_svg("%s.svg" % file_prefix, prog='dot')

    print "Created svg"

if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        description="Generate a PDU graph for a given room by reading "
                    "from a file with line deliminated events. \n"
                    "Requires pydot."
    )
    parser.add_argument(
        "-p", "--prefix", dest="prefix",
        help="String to prefix output files with",
        default="graph_output"
    )
    parser.add_argument(
        "-l", "--limit",
        help="Only retrieve the last N events.",
    )
    parser.add_argument('event_file')
    parser.add_argument('room')

    args = parser.parse_args()

    make_graph(args.event_file, args.room, args.prefix, args.limit)