#!/usr/bin/python

# Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
# for details. All rights reserved. Use of this source code is governed by a
# BSD-style license that can be found in the LICENSE file.

import json
import re
import sys

import bot
import bot_utils

utils = bot_utils.GetUtils()

VERSION_BUILDER = r'versionchecker'


def VersionConfig(name, is_buildbot):
    version_pattern = re.match(VERSION_BUILDER, name)
    if not version_pattern:
        return None
    # We don't really use this, but we create it anyway to use the standard
    # bot execution model.
    return bot.BuildInfo('none', 'none', 'release', 'linux')


def GetLatestVersionFromGCS(channel):
    namer = bot_utils.GCSNamer(channel=channel)
    gsutil = bot_utils.GSUtil()
    gcs_version_path = namer.version_filepath('latest')
    print 'Getting latest version from: %s' % gcs_version_path
    version_json = gsutil.cat(gcs_version_path)
    version_map = json.loads(version_json)
    return version_map['version']


def ValidateChannelVersion(latest_version, channel):
    repo_version = utils.ReadVersionFile()
    assert repo_version.channel == channel
    if channel == bot_utils.Channel.STABLE:
        assert int(repo_version.prerelease) == 0
        assert int(repo_version.prerelease_patch) == 0

    version_re = r'(\d+)\.(\d+)\.(\d+)(-dev\.(\d+)\.(\d+))?'

    latest_match = re.match(version_re, latest_version)
    latest_major = int(latest_match.group(1))
    latest_minor = int(latest_match.group(2))
    latest_patch = int(latest_match.group(3))
    # We don't use these on stable.
    latest_prerelease = int(latest_match.group(5) or 0)
    latest_prerelease_patch = int(latest_match.group(6) or 0)

    if latest_major < int(repo_version.major):
        return True
    if latest_minor < int(repo_version.minor):
        return True
    if latest_patch < int(repo_version.patch):
        return True
    if latest_prerelease < int(repo_version.prerelease):
        return True
    if latest_prerelease_patch < int(repo_version.prerelease_patch):
        return True
    return False


def VersionSteps(build_info):
    with bot.BuildStep('Version file sanity checking'):
        bot_name, _ = bot.GetBotName()
        channel = bot_utils.GetChannelFromName(bot_name)
        if channel == bot_utils.Channel.BLEEDING_EDGE:
            print 'No sanity checking on bleeding edge'
        else:
            assert (channel == bot_utils.Channel.STABLE or
                    channel == bot_utils.Channel.DEV or
                    channel == bot_utils.Channel.BETA)
            latest_version = GetLatestVersionFromGCS(channel)
            version = utils.GetVersion()
            print 'Latests version on GCS: %s' % latest_version
            print 'Version currently building: %s' % version
            if not ValidateChannelVersion(latest_version, channel):
                print "Validation failed"
                sys.exit(1)
            else:
                print 'Version file changed, sanity checks passed'


if __name__ == '__main__':
    # We pass in None for build_step to avoid building.
    bot.RunBot(VersionConfig, VersionSteps, build_step=None)