#!/usr/bin/env python3

# This file is part of Cockpit.
#
# Copyright (C) 2017 Red Hat, Inc.
#
# Cockpit is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Cockpit 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Cockpit; If not, see <http://www.gnu.org/licenses/>.

import argparse
import os
import shutil
import subprocess
import sys
from task import github

sys.dont_write_bytecode = True

# Check out the given ref and if necessary overlay the bots
# directory on top of it as expected on non-master branches

BOTS = os.path.dirname(__file__)
BASE = os.path.normpath(os.path.join(BOTS, ".."))
TARGET_DIR = os.path.join(BOTS, "make-checkout-workdir")

def main():
    parser = argparse.ArgumentParser(description="Fetch and checkout specific revision")
    parser.add_argument("-v", "--verbose", action="store_true", help="Verbose output")
    parser.add_argument("--base", nargs='?', help="Base branch that revision is for")
    parser.add_argument("--repo", nargs='?', help="Repository to check out")
    parser.add_argument("--bots-ref", help="bots/ ref to check out from cockpit, for non-default --repo")
    parser.add_argument("ref", help="The git ref to fetch")
    parser.add_argument("revision", nargs='?', help="Actual commit to check out, defaults to ref")

    opts = parser.parse_args()
    if not opts.revision:
        opts.revision = "FETCH_HEAD"

    api = github.GitHub(repo=opts.repo)

    def execute(*args, cwd=BASE, error_on_fail=True):
        output = None
        if opts.verbose:
            sys.stderr.write("+ " + " ".join(args) + "\n")
        try:
            output = subprocess.check_output(args, cwd=cwd, universal_newlines=True)
        except subprocess.CalledProcessError as ex:
            sys.exit(ex.returncode if error_on_fail else 0)
        finally:
            if opts.verbose and output:
                sys.stderr.write("> " + output + "\n")
        return output

    if os.path.exists(TARGET_DIR):
        shutil.rmtree(TARGET_DIR)

    cache = os.getenv('XDG_CACHE_HOME', ".")
    execute("git", "clone", "--reference-if-able", "{}/{}".format(cache, api.repo), "https://github.com/{}".format(api.repo), TARGET_DIR)
    execute("git", "fetch", "origin", opts.ref, cwd=TARGET_DIR, error_on_fail=False)
    execute("git", "checkout", "--detach", opts.revision, cwd=TARGET_DIR, error_on_fail=False)

    # get bots/
    if api.repo != "cockpit-project/cockpit" or (opts.base and opts.base != "master"):
        execute("git", "remote", "add", "bots_origin", "https://github.com/cockpit-project/cockpit", cwd=TARGET_DIR)
        execute("git", "fetch", "--depth=1", "bots_origin", opts.bots_ref or "master", cwd=TARGET_DIR)
        bots_ref = execute("git", "rev-parse", "FETCH_HEAD", cwd=TARGET_DIR).strip()
        execute("git", "checkout", "--force", bots_ref or "bots_origin/master", "--", "bots/", cwd=TARGET_DIR, error_on_fail=False)

if __name__ == '__main__':
    sys.exit(main())