#!/usr/bin/python3
#
# Copyright (C) 2018 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# File: make-version-file
# Purpose:
#   Creates version file in live-build chroot includes dir
#   that is included in the image and used by 'show version' command
#   and install/upgrade scripts.

import os
import datetime
import json
import uuid

import git

import defaults
import util

# Load the build config
util.check_build_config()
with open(defaults.BUILD_CONFIG, 'r') as f:
     build_config = json.load(f)

# Create a build timestamp
now = datetime.datetime.today()
build_timestamp = now.strftime("%Y%m%d%H%M")

# FIXME: use aware rather than naive object
build_date = now.strftime("%a %d %b %Y %H:%M UTC")

# Assign a (hopefully) unique identifier to the build (UUID)
build_uuid = str(uuid.uuid4())

# Initialize Git object from our repository
try:
    repo = git.Repo('.')

    # Retrieve the Git commit ID of the repository, 14 charaters will be sufficient
    build_git = repo.head.object.hexsha[:14]
    # If somone played around with the source tree and the build is "dirty", mark it
    if repo.is_dirty():
        build_git += "-dirty"

    # Retrieve git branch name
    git_branch = repo.active_branch.name
except Exception as e:
  print("Could not retrieve information from git: {0}".format(str(e)))
  build_git = ""
  git_branch = ""
  git_commit = ""

# Create a build version
if build_config['build_type'] == 'development':
    try:
        if not git_branch:
            raise ValueError("git branch could not be determined")

        # Load the branch to version mapping file
        with open('data/versions') as f:
            version_mapping = json.load(f)

        branch_version = version_mapping[git_branch]

        version = "{0}-rolling-{1}".format(branch_version, build_timestamp)
    except Exception as e:
        print("Could not build a version string specific to git branch, falling back to default: {0}".format(str(e)))
        version = "999.{0}".format(build_timestamp)
else:
    # Release build, use the version from ./configure arguments
    version = build_config['version']

if build_config['build_type'] == 'development':
    lts_build = False
else:
    lts_build = True

version_data = {
    'version': version,
    'built_by': build_config['build_by'],
    'built_on': build_date,
    'build_uuid': build_uuid,
    'build_git': build_git,
    'build_branch': git_branch,
    'release_train': build_config['release_train'],
    'lts_build': lts_build,
    'build_comment': build_config['build_comment']
}

os.makedirs(os.path.join(defaults.CHROOT_INCLUDES_DIR, 'usr/share/vyos'), exist_ok=True)
with open(os.path.join(defaults.CHROOT_INCLUDES_DIR, 'usr/share/vyos/version.json'), 'w') as f:
    json.dump(version_data, f)

# For backwards compatibility with 'add system image' script from older versions
# we need a file in the old format so that script can find out the version of the image
# for upgrade
os.makedirs(os.path.join(defaults.CHROOT_INCLUDES_DIR, 'opt/vyatta/etc/'), exist_ok=True)
with open(os.path.join(defaults.CHROOT_INCLUDES_DIR, 'opt/vyatta/etc/version'), 'w') as f:
    print("Version: {0}".format(version), file=f)

# Leaky abstraction: we want ISO file name include version number,
# but we probably don't want to  have a separate build step just for this,
# neither we want to use lengthy paths in makefiles
with open(os.path.join(defaults.BUILD_DIR, 'version'), 'w') as f:
    print(version, file=f)