#!/usr/bin/env python
# Copyright (c) 2011 OpenStack, LLC.
#
# 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 is designed to be called by a gerrit hook.  It searched new
# patchsets for strings like "blueprint FOO" or "bp FOO" and updates
# corresponding Launchpad blueprints with links back to the change.

import argparse
import ConfigParser
import os
import re
import StringIO
import subprocess

from launchpadlib import launchpad
from launchpadlib import uris
import MySQLdb

from jeepyb import projects as p


BASE_DIR = '/home/gerrit2/review_site'
GERRIT_CACHE_DIR = os.path.expanduser(
    os.environ.get('GERRIT_CACHE_DIR',
                   '~/.launchpadlib/cache'))
GERRIT_CREDENTIALS = os.path.expanduser(
    os.environ.get('GERRIT_CREDENTIALS',
                   '~/.launchpadlib/creds'))
GERRIT_CONFIG = os.environ.get('GERRIT_CONFIG',
                               '/home/gerrit2/review_site/etc/gerrit.config')
GERRIT_SECURE_CONFIG_DEFAULT = '/home/gerrit2/review_site/etc/secure.config'
GERRIT_SECURE_CONFIG = os.environ.get('GERRIT_SECURE_CONFIG',
                                      GERRIT_SECURE_CONFIG_DEFAULT)
SPEC_RE = re.compile(r'\b(blueprint|bp)\b[ \t]*[#:]?[ \t]*(\S+)', re.I)
BODY_RE = re.compile(r'^\s+.*$')


def get_broken_config(filename):
    """gerrit config ini files are broken and have leading tabs."""
    text = ""
    with open(filename, "r") as conf:
        for line in conf.readlines():
            text = "%s%s" % (text, line.lstrip())

    fp = StringIO.StringIO(text)
    c = ConfigParser.ConfigParser()
    c.readfp(fp)
    return c

GERRIT_CONFIG = get_broken_config(GERRIT_CONFIG)
SECURE_CONFIG = get_broken_config(GERRIT_SECURE_CONFIG)
DB_HOST = GERRIT_CONFIG.get("database", "hostname")
DB_USER = GERRIT_CONFIG.get("database", "username")
DB_PASS = SECURE_CONFIG.get("database", "password")
DB_DB = GERRIT_CONFIG.get("database", "database")


def update_spec(launchpad, project, name, subject, link, topic=None):
    if p.is_no_launchpad_blueprints(project):
        return

    project = p.project_to_group(project)
    spec = launchpad.projects[project].getSpecification(name=name)
    if not spec:
        return

    if spec.whiteboard:
        wb = spec.whiteboard.strip()
    else:
        wb = ''
    changed = False
    if topic:
        topiclink = '%s/#q,topic:%s,n,z' % (link[:link.find('/', 8)],
                                            topic)
        if topiclink not in wb:
            wb += "\n\n\nGerrit topic: %(link)s" % dict(link=topiclink)
            changed = True

    if link not in wb:
        wb += ("\n\n\nAddressed by: {link}\n"
               "    {subject}\n").format(subject=subject,
                                         link=link)
        changed = True

    if changed:
        spec.whiteboard = wb
        spec.lp_save()


def find_specs(launchpad, dbconn, args):
    git_dir_arg = '--git-dir={base_dir}/git/{project}.git'.format(
        base_dir=BASE_DIR,
        project=args.project)
    git_log = subprocess.Popen(['git', git_dir_arg, 'log', '--no-merges',
                                args.commit + '^1..' + args.commit],
                               stdout=subprocess.PIPE).communicate()[0]

    cur = dbconn.cursor()
    cur.execute("select subject, topic from changes where change_key=%s",
                args.change)
    subject, topic = cur.fetchone()
    specs = set([m.group(2) for m in SPEC_RE.finditer(git_log)])

    if topic:
        topicspec = topic.split('/')[-1]
        specs |= set([topicspec])

    for spec in specs:
        update_spec(launchpad, args.project, spec, subject,
                    args.change_url, topic)


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('hook')
    #common
    parser.add_argument('--change', default=None)
    parser.add_argument('--change-url', default=None)
    parser.add_argument('--project', default=None)
    parser.add_argument('--branch', default=None)
    parser.add_argument('--commit', default=None)
    parser.add_argument('--topic', default=None)
    #change-merged
    parser.add_argument('--submitter', default=None)
    # patchset-created
    parser.add_argument('--uploader', default=None)
    parser.add_argument('--patchset', default=None)
    parser.add_argument('--is-draft', default=None)

    args = parser.parse_args()

    lpconn = launchpad.Launchpad.login_with(
        'Gerrit User Sync', uris.LPNET_SERVICE_ROOT, GERRIT_CACHE_DIR,
        credentials_file=GERRIT_CREDENTIALS, version='devel')

    conn = MySQLdb.connect(
        host=DB_HOST, user=DB_USER, passwd=DB_PASS, db=DB_DB)

    find_specs(lpconn, conn, args)

if __name__ == "__main__":
    main()