#!/usr/bin/env python
"""Change source forwarder for bitbucket.org POST service.

bitbucket_buildbot.py will determine the repository information from
the JSON HTTP POST it receives from bitbucket.org and build the
appropriate repository.

If your bitbucket repository is private, you must add a ssh key to the
bitbucket repository for the user who initiated bitbucket_buildbot.py

bitbucket_buildbot.py is based on github_buildbot.py
"""

import logging
import sys
import tempfile
import traceback

from optparse import OptionParser

from twisted.cred import credentials
from twisted.internet import reactor
from twisted.spread import pb
from twisted.web import resource
from twisted.web import server

try:
    import json
except ImportError:
    import simplejson as json


class BitBucketBuildBot(resource.Resource):

    """
    BitBucketBuildBot creates the webserver that responds to the
    BitBucket POST Service Hook.
    """
    isLeaf = True
    bitbucket = None
    master = None
    port = None
    private = False

    def render_POST(self, request):
        """
        Responds only to POST events and starts the build process

        :arguments:
            request
                the http request object
        """
        try:
            payload = json.loads(request.args['payload'][0])
            logging.debug("Payload: " + str(payload))
            self.process_change(payload)
        except Exception:
            logging.error("Encountered an exception:")
            for msg in traceback.format_exception(*sys.exc_info()):
                logging.error(msg.strip())

    def process_change(self, payload):
        """
        Consumes the JSON as a python object and actually starts the build.

        :arguments:
            payload
                Python Object that represents the JSON sent by Bitbucket POST
                Service Hook.
        """
        if self.private:
            repo_url = 'ssh://hg@%s%s' % (
                self.bitbucket,
                payload['repository']['absolute_url'],
            )
        else:
            repo_url = 'http://%s%s' % (
                self.bitbucket,
                payload['repository']['absolute_url'],
            )
        changes = []
        for commit in payload['commits']:
            files = [file_info['file'] for file_info in commit['files']]
            revlink = 'http://%s%s/changeset/%s/' % (
                self.bitbucket,
                payload['repository']['absolute_url'],
                commit['node'],
            )
            change = {
                'revision': commit['node'],
                'revlink': revlink,
                'comments': commit['message'],
                'who': commit['author'],
                'files': files,
                'repository': repo_url,
                'properties': dict(),
            }
            changes.append(change)
        # Submit the changes, if any
        if not changes:
            logging.warning("No changes found")
            return
        host, port = self.master.split(':')
        port = int(port)
        factory = pb.PBClientFactory()
        deferred = factory.login(credentials.UsernamePassword("change",
                                                              "changepw"))
        logging.debug('Trying to connect to: %s:%d', host, port)
        reactor.connectTCP(host, port, factory)
        deferred.addErrback(self.connectFailed)
        deferred.addCallback(self.connected, changes)

    def connectFailed(self, error):
        """
        If connection is failed.  Logs the error.
        """
        logging.error("Could not connect to master: %s",
                      error.getErrorMessage())
        return error

    def addChange(self, dummy, remote, changei, src='hg'):
        """
        Sends changes from the commit to the buildmaster.
        """
        logging.debug("addChange %s, %s", repr(remote), repr(changei))
        try:
            change = changei.next()
        except StopIteration:
            remote.broker.transport.loseConnection()
            return None

        logging.info("New revision: %s", change['revision'][:8])
        for key, value in change.iteritems():
            logging.debug("  %s: %s", key, value)

        change['src'] = src
        deferred = remote.callRemote('addChange', change)
        deferred.addCallback(self.addChange, remote, changei, src)
        return deferred

    def connected(self, remote, changes):
        """
        Responds to the connected event.
        """
        return self.addChange(None, remote, changes.__iter__())


def main():
    """
    The main event loop that starts the server and configures it.
    """
    usage = "usage: %prog [options]"
    parser = OptionParser(usage)
    parser.add_option(
        "-p", "--port",
        help="Port the HTTP server listens to for the Bitbucket Service Hook"
        " [default: %default]", default=4000, type=int, dest="port")
    parser.add_option(
        "-m", "--buildmaster",
        help="Buildbot Master host and port. ie: localhost:9989 [default:"
        + " %default]", default="localhost:9989", dest="buildmaster")
    parser.add_option(
        "-l", "--log",
        help="The absolute path, including filename, to save the log to"
        " [default: %default]",
        default=tempfile.gettempdir() + "/bitbucket_buildbot.log",
        dest="log")
    parser.add_option(
        "-L", "--level",
        help="The logging level: debug, info, warn, error, fatal [default:"
        " %default]", default='warn', dest="level")
    parser.add_option(
        "-g", "--bitbucket",
        help="The bitbucket serve [default: %default]",
        default='bitbucket.org',
        dest="bitbucket")
    parser.add_option(
        '-P', '--private',
        help='Use SSH to connect, for private repositories.',
        dest='private',
        default=False,
        action='store_true',
    )
    (options, _) = parser.parse_args()
    # Set up logging.
    levels = {
        'debug': logging.DEBUG,
        'info': logging.INFO,
        'warn': logging.WARNING,
        'error': logging.ERROR,
        'fatal': logging.FATAL,
    }
    filename = options.log
    log_format = "%(asctime)s - %(levelname)s - %(message)s"
    logging.basicConfig(filename=filename, format=log_format,
                        level=levels[options.level])
    # Start listener.
    bitbucket_bot = BitBucketBuildBot()
    bitbucket_bot.bitbucket = options.bitbucket
    bitbucket_bot.master = options.buildmaster
    bitbucket_bot.private = options.private
    site = server.Site(bitbucket_bot)
    reactor.listenTCP(options.port, site)
    reactor.run()


if __name__ == '__main__':
    main()
