# 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 copy


def loader(kind, path, config, params, loaded_tasks):
    """
    Load tasks based on the jobs dependant kinds.

    The `only-for-build-platforms` kind configuration, if specified, will limit
    the build platforms for which a job will be created. Alternatively there is
    'not-for-build-platforms' kind configuration which will be consulted only after
    'only-for-build-platforms' is checked (if present), and omit any jobs where the
    build platform matches.

    Optional `only-for-attributes` kind configuration, if specified, will limit
    the jobs chosen to ones which have the specified attribute, with the specified
    value.

    Optional `job-template` kind configuration value, if specified, will be used to
    pass configuration down to the specified transforms used.
    """
    only_platforms = config.get('only-for-build-platforms')
    not_platforms = config.get('not-for-build-platforms')
    only_attributes = config.get('only-for-attributes')
    job_template = config.get('job-template')

    for task in loaded_tasks:
        if task.kind not in config.get('kind-dependencies', []):
            continue

        if only_platforms or not_platforms:
            build_platform = task.attributes.get('build_platform')
            build_type = task.attributes.get('build_type')
            if not build_platform or not build_type:
                continue
            platform = "{}/{}".format(build_platform, build_type)
            if only_platforms and platform not in only_platforms:
                continue
            elif not_platforms and platform in not_platforms:
                continue

        if only_attributes:
            config_attrs = set(only_attributes)
            if config_attrs - set(task.attributes):
                # make sure all attributes exist
                continue

        job = {'dependent-task': task}
        if job_template:
            job.update(copy.deepcopy(job_template))

        yield job
