#!/usr/bin/env python
# Copyright 2012 OpenStack Foundation
#
# 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 ConfigParser
import datetime
import re
import sys
import threading
import traceback
import cPickle as pickle
import os

from genshi.template import TemplateLoader
from launchpadlib.launchpad import Launchpad
from launchpadlib.uris import LPNET_SERVICE_ROOT
import daemon

CLOSED_STATUSES = ['Fix Released', 'Invalid', 'Fix Committed']

try:
    import daemon.pidlockfile
    pid_file_module = daemon.pidlockfile
except:
    # as of python-daemon 1.6 it doesn't bundle pidlockfile anymore
    # instead it depends on lockfile-0.9.1
    import daemon.pidfile
    pid_file_module = daemon.pidfile


class Hit(object):
    def __init__(self, project, change):
        self.project = project
        self.change = change
        self.ts = datetime.datetime.utcnow()

class Bug(object):
    def __init__(self, number):
        self.number = number
        self.hits = []
        self.projects = []
        self.changes = []
        self.last_seen = None
        self.first_seen = None
        self.update()

    def update(self):
        launchpad = Launchpad.login_anonymously('recheckwatch',
                                                'production')
        lpitem = launchpad.bugs[self.number]
        self.title = lpitem.title
        self.status = map(lambda x: x.status,
                          lpitem.bug_tasks)

    def is_closed(self):
        closed = True
        for status in self.status:
            if status not in CLOSED_STATUSES:
                closed = False
        return closed

    def addHit(self, hit):
        self.hits.append(hit)
        if not self.first_seen:
            self.first_seen = hit.ts
        if hit.project not in self.projects:
            self.projects.append(hit.project)
        if hit.change not in self.changes:
            self.changes.append(hit.change)
        self.last_seen = hit.ts

class Scoreboard(threading.Thread):
    def __init__(self, config):
        threading.Thread.__init__(self)
        self.scores = {}

        server = config.get('gerrit', 'host')
        username = config.get('gerrit', 'user')
        port = config.getint('gerrit', 'port')
        keyfile = config.get('gerrit', 'key', None)

        self.pickle_dir = config.get('recheckwatch', 'pickle_dir')
        self.pickle_file = os.path.join(self.pickle_dir, 'scoreboard.pickle')
        self.template_dir = config.get('recheckwatch', 'template_dir')
        self.output_file = config.get('recheckwatch', 'output_file')
        self.age = config.getint('recheckwatch', 'age')
        self.regex = re.compile(config.get('recheckwatch', 'regex'))

        if os.path.exists(self.pickle_file):
            out = open(self.pickle_file, 'rb')
            self.scores = pickle.load(out)
            out.close()

        # Import here because it needs to happen after daemonization
        import gerritlib.gerrit
        self.gerrit = gerritlib.gerrit.Gerrit(server, username, port, keyfile)
        self.update()

    def _read(self, data):
        if data.get('type', '') != 'comment-added':
            return
        comment = data.get('comment', '')
        m = self.regex.match(comment.strip())
        if not m:
            return
        change_record = data.get('change', {})
        change = change_record.get('number')
        project = change_record.get('project')
        bugno = int(m.group('bugno'))
        hit = Hit(project, change)
        bug = self.scores.get(bugno)
        if not bug:
            bug = Bug(bugno)
        bug.addHit(hit)
        self.scores[bugno] = bug
        self.update()

    def update(self):
        # Remove bugs that haven't been seen in ages
        to_remove = []
        now = datetime.datetime.utcnow()
        for bugno, bug in self.scores.items():
            if bug.last_seen < now-datetime.timedelta(days=self.age):
                to_remove.append(bugno)
        for bugno in to_remove:
            del self.scores[bugno]

        def impact(bug):
            """Golf rules for bugs, smaller the more urgent."""
            age = (now - bug.last_seen).total_seconds()

            if bug.is_closed():
                age = age + (5.0 * 86400.0)

            return age

        # Get the bugs reverse sorted by impact
        bugs = self.scores.values()
        # freshen to get lp bug status
        for bug in bugs:
            bug.update()
        bugs.sort(lambda a,b: cmp(impact(a), impact(b)))

        loader = TemplateLoader([self.template_dir], auto_reload=True)
        tmpl = loader.load('scoreboard.html')
        out = open(self.output_file, 'w')
        out.write(tmpl.generate(bugs = bugs).render('html', doctype='html'))

        out = open(self.pickle_file, 'wb')
        pickle.dump(self.scores, out, -1)
        out.close()

    def run(self):
        self.gerrit.startWatching()
        while True:
            event = self.gerrit.getEvent()
            try:
                self._read(event)
            except:
                traceback.print_exc()

def _main(daemonize=True):
    config = ConfigParser.ConfigParser()
    config.read(sys.argv[1])

    s = Scoreboard(config)
    if daemonize:
        s.start()

def main():
    if len(sys.argv) < 2:
        print "Usage: %s CONFIGFILE" % sys.argv[0]
        sys.exit(1)

    if '-n' in sys.argv:
        _main(daemonize=False)
    elif '-d' in sys.argv:
        _main()
    else:
        pid = pid_file_module.TimeoutPIDLockFile(
            "/var/run/recheckwatch/recheckwatch.pid", 10)
        with daemon.DaemonContext(pidfile=pid):
            _main()

if __name__ == "__main__":
    main()