# -*- coding: utf-8 -*-

# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.


from __future__ import absolute_import, print_function, unicode_literals

import jsone
import pipes
import yaml
import os
import slugid

from taskgraph.util.time import current_json_time
from taskgraph.util.hg import find_hg_revision_push_info


def run_decision_task(job, params, root):
    arguments = []
    if 'target-tasks-method' in job:
        arguments.append('--target-tasks-method={}'.format(job['target-tasks-method']))
    return [
        make_decision_task(
            params,
            symbol=job['treeherder-symbol'],
            arguments=arguments,
            root=root),
    ]


def make_decision_task(params, root, symbol, arguments=[], head_rev=None):
    """Generate a basic decision task, based on the root .taskcluster.yml"""
    with open(os.path.join(root, '.taskcluster.yml'), 'rb') as f:
        taskcluster_yml = yaml.safe_load(f)

    if not head_rev:
        head_rev = params['head_rev']
    push_info = find_hg_revision_push_info(
        params['repository_url'],
        params['head_rev'])

    slugids = {}

    def as_slugid(name):
        # https://github.com/taskcluster/json-e/issues/164
        name = name[0]
        if name not in slugids:
            slugids[name] = slugid.nice()
        return slugids[name]

    # provide a similar JSON-e context to what mozilla-taskcluster provides:
    # https://docs.taskcluster.net/reference/integrations/mozilla-taskcluster/docs/taskcluster-yml
    # but with a different tasks_for and an extra `cron` section
    context = {
        'tasks_for': 'cron',
        'repository': {
            'url': params['repository_url'],
            'project': params['project'],
            'level': params['level'],
        },
        'push': {
            'revision': params['head_rev'],
            # remainder are fake values, but the decision task expects them anyway
            'pushlog_id': push_info['pushid'],
            'pushdate': push_info['pushdate'],
            'owner': 'cron',
            'comment': '',
        },
        'cron': {
            'task_id': os.environ.get('TASK_ID', '<cron task id>'),
            'job_name': params['job_name'],
            'job_symbol': symbol,
            # args are shell-quoted since they are given to `bash -c`
            'quoted_args': ' '.join(pipes.quote(a) for a in arguments),
        },
        'now': current_json_time(),
        'as_slugid': as_slugid,
    }

    rendered = jsone.render(taskcluster_yml, context)
    if len(rendered['tasks']) != 1:
        raise Exception("Expected .taskcluster.yml to only produce one cron task")
    task = rendered['tasks'][0]

    task_id = task.pop('taskId')
    return (task_id, task)