#!/usr/bin/env python

"""

 (c) 2015 - Copyright Red Hat Inc

 Authors:

   Pierre-Yves Chibon <pingou@pingoured.fr></pingou@pingoured.fr>

Streaming server for pagure's eventsource feature

This server takes messages sent to redis and publish them at the specified

endpoint

To test, run this script and in another terminal

nc localhost 8080

  HELLO

  GET /test/issue/26?foo=bar HTTP/1.1

"""

import datetime

import logging

import os

import urlparse

import trollius

import trollius_redis

log = logging.getLogger(__name__)

if 'PAGURE_CONFIG' not in os.environ \

        and os.path.exists('/etc/pagure/pagure.cfg'):

    print 'Using configuration file `/etc/pagure/pagure.cfg`'

    os.environ['PAGURE_CONFIG'] = '/etc/pagure/pagure.cfg'

import pagure

import pagure.lib

from pagure.exceptions import PagureEvException

SERVER = None

def get_obj_from_path(path):

    """ Return the Ticket or Request object based on the path provided.

    """

    username = None

    try:

        if path.startswith('/fork'):

            username, repo, obj, objid = path.split('/')[2:6]

        else:

            repo, obj, objid = path.split('/')[1:4]

    except:

        raise PagureEvException("Invalid URL: %s" % path)

    repo = pagure.lib.get_project(pagure.SESSION, repo, user=username)

    if repo is None:

        raise PagureEvException("Project '%s' not found" % repo)

    output = None

    if obj == 'issue':

        if not repo.settings.get('issue_tracker', True):

            raise PagureEvException("No issue tracker found for this project")

        output = pagure.lib.search_issues(

            pagure.SESSION, repo, issueid=objid)

        if output is None or output.project != repo:

            raise PagureEvException("Issue '%s' not found" % objid)

        if output.private:

            # TODO: find a way to do auth

            raise PagureEvException(

                "This issue is private and you are not allowed to view it")

    elif obj == 'pull-request':

        if not repo.settings.get('pull_requests', True):

            raise PagureEvException(

                "No pull-request tracker found for this project")

        output = pagure.lib.search_pull_requests(

            pagure.SESSION, project_id=repo.id, requestid=objid)

        if output is None or output.project != repo:

            raise PagureEvException("Pull-Request '%s' not found" % objid)

    else:

        raise PagureEvException("Invalid object provided: '%s'" % obj)

    return output

@trollius.coroutine

def handle_client(client_reader, client_writer):

    data = None

    while True:

        # give client a chance to respond, timeout after 10 seconds

        line = yield trollius.From(trollius.wait_for(

            client_reader.readline(),

            timeout=10.0))

        if not line.decode().strip():

            break

        line = line.decode().rstrip()

        if data is None:

            data = line

    if data is None:

        log.warning("Expected ticket uid, received None")

        return

    data = data.decode().rstrip().split()

    log.info("Received %s", data)

    if not data:

        log.warning("No URL provided: %s" % data)

        return

    if not '/' in data[1]:

        log.warning("Invalid URL provided: %s" % data[1])

        return

    url = urlparse.urlsplit(data[1])

    try:

        obj = get_obj_from_path(url.path)

    except PagureEvException as err:

        log.warning(err.message)

        return

    origin = pagure.APP.config.get('APP_URL')

    if origin.endswith('/'):

        origin = origin[:-1]

    client_writer.write((

        "HTTP/1.0 200 OK\n"

        "Content-Type: text/event-stream\n"

        "Cache: nocache\n"

        "Connection: keep-alive\n"

        "Access-Control-Allow-Origin: %s\n\n" % origin

    ).encode())

    connection = yield trollius.From(trollius_redis.Connection.create(

        host=pagure.APP.config['REDIS_HOST'],

        port=pagure.APP.config['REDIS_PORT'],

        db=pagure.APP.config['REDIS_DB']))

    try:

        # Create subscriber.

        subscriber = yield trollius.From(connection.start_subscribe())

        # Subscribe to channel.

        yield trollius.From(subscriber.subscribe(['pagure.%s' % obj.uid]))

        # Inside a while loop, wait for incoming events.

        while True:

            reply = yield trollius.From(subscriber.next_published())

            #print(u'Received: ', repr(reply.value), u'on channel', reply.channel)

            log.info(reply)

            log.info("Sending %s", reply.value)

            client_writer.write(('data: %s\n\n' % reply.value).encode())

            yield trollius.From(client_writer.drain())

    except trollius.ConnectionResetError as err:

        log.exception("ERROR: ConnectionResetError in handle_client")

    except Exception as err:

        log.exception("ERROR: Exception in handle_client")

    finally:

        # Wathever happens, close the connection.

        connection.close()

        client_writer.close()

@trollius.coroutine

def stats(client_reader, client_writer):

    try:

        log.info('Clients: %s', SERVER.active_count)

        client_writer.write((

            "HTTP/1.0 200 OK\n"

            "Cache: nocache\n\n"

        ).encode())

        client_writer.write(('data: %s\n\n' % SERVER.active_count).encode())

        yield trollius.From(client_writer.drain())

    except trollius.ConnectionResetError as err:

        log.info(err)

        pass

    finally:

        client_writer.close()

    return

def main():

    global SERVER

    try:

        loop = trollius.get_event_loop()

        coro = trollius.start_server(

            handle_client,

            host=None,

            port=pagure.APP.config['EVENTSOURCE_PORT'],

            loop=loop)

        SERVER = loop.run_until_complete(coro)

        log.info('Serving server at {}'.format(SERVER.sockets[0].getsockname()))

        if pagure.APP.config.get('EV_STATS_PORT'):

            stats_coro = trollius.start_server(

                stats,

                host=None,

                port=pagure.APP.config.get('EV_STATS_PORT'),

                loop=loop)

            stats_server = loop.run_until_complete(stats_coro)

            log.info('Serving stats  at {}'.format(

                stats_server.sockets[0].getsockname()))

        loop.run_forever()

    except KeyboardInterrupt:

        pass

    except trollius.ConnectionResetError as err:

        log.exception("ERROR: ConnectionResetError in main")

    except Exception as err:

        log.exception("ERROR: Exception in main")

    finally:

        # Close the server

        SERVER.close()

        if pagure.APP.config.get('EV_STATS_PORT'):

            stats_server.close()

        log.info("End Connection")

        loop.run_until_complete(SERVER.wait_closed())

        loop.close()

        log.info("End")

if __name__ == '__main__':

    log = logging.getLogger("")

    formatter = logging.Formatter(

        "%(asctime)s %(levelname)s [%(module)s:%(lineno)d] %(message)s")

    # setup console logging

    log.setLevel(logging.DEBUG)

    ch = logging.StreamHandler()

    ch.setLevel(logging.DEBUG)

    aslog = logging.getLogger("asyncio")

    aslog.setLevel(logging.DEBUG)

    ch.setFormatter(formatter)

    log.addHandler(ch)

    main()