#!/bin/env python3
# Copyright 2013 OpenStack Foundation
# Copyright 2015 Hewlett-Packard Development Company, L.P.
# Copyright 2016 Red Hat
#
# 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 requests
import argparse
import os
import time


dump_file = "/var/lib/zuul/zuul-queues-dump.sh"


def get_tenants(args):
    req = requests.get("%s/tenants" % args.url)
    tenants = req.json()
    status = {}
    for tenant in tenants:
        req = requests.get("%s/tenant/%s/status" % (args.url, tenant["name"]))
        status[tenant["name"]] = req.json()
    if os.path.isfile(args.dump_file):
        os.rename(args.dump_file, "%s.orig" % args.dump_file)
    return (tenants, status)


def retry_get_tenants(args):
    count, max_count = 0, 5
    while True:
        try:
            return get_tenants(args)
        except Exception as e:
            if count > max_count:
                raise e
            count += 1
            print("Request fails (%s), retrying %d/%d" %
                  (str(e), count, max_count))
            time.sleep(count * 2)


def dump(args):
    (tenants, status) = retry_get_tenants(args)
    of = open(args.dump_file, "w")
    of.write("#/bin/sh\nset -ex\n")
    for tenant in tenants:
        for pipeline in status[tenant["name"]].get('pipelines', []):
            for queue in pipeline['change_queues']:
                for head in queue['heads']:
                    for change in head:
                        if (not change['live'] or
                                not change.get('id') or
                                ',' not in change['id']):
                            continue
                        cid, cps = change['id'].split(',')
                        cmd = (
                            "zuul-client enqueue --tenant %s "
                            "--pipeline %s --project %s --change %s,%s" % (
                                tenant["name"],
                                pipeline['name'],
                                change['project_canonical'],
                                cid, cps)
                        )
                        if ";" in cmd or "|" in cmd:
                            raise RuntimeError("Forbidden char in [%s]" % cmd)
                        print(cmd)
                        of.write("%s\n" % cmd)
    of.write(
        "curl %s/info 2>&1 | grep 'capabilities' > /dev/null\n" % args.url)
    of.write("echo SUCCESS: zuul queues restored\n")
    of.close()
    os.chmod(args.dump_file, 0o755)


def load(args):
    if not os.path.isfile(args.dump_file):
        print("%s: no such file, please dump first" % args.dump_file)
    if os.stat(args.dump_file).st_mtime + 172800 < time.time():
        if not args.force:
            raise RuntimeError("%s is too old, use --force to use it" %
                               args.dump_file)
    os.system(dump_file)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument('--force', action="store_const", const=True)
    parser.add_argument('--url', default="{{ .ZuulWebURL }}/api")
    parser.add_argument('--dump_file', default=dump_file)
    parser.add_argument('action', choices=("dump", "load"))
    args = parser.parse_args()
    if args.action == "dump":
        dump(args)
    else:
        load(args)