# 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


# Define a collection of group_by functions
GROUP_BY_MAP = {}


def group_by(name):
    def wrapper(func):
        GROUP_BY_MAP[name] = func
        return func
    return wrapper



def group_tasks(config, tasks):
    group_by_fn = GROUP_BY_MAP[config['group-by']]

    groups = group_by_fn(config, tasks)

    for combinations in groups.itervalues():
        dependencies = [copy.deepcopy(t) for t in combinations]
        yield dependencies


@group_by('component')
def component_grouping(config, tasks):
    only_build_types = config.get("only-for-build-types")

    groups = {}
    for task in tasks:
        if task.kind not in config.get("kind-dependencies", []):
            continue

        component = task.attributes.get("component")
        if component == "all":
            continue

        build_type = task.attributes.get("build-type")

        # Skip only_ and build_types that don't match
        if only_build_types:
            if not build_type or build_type not in only_build_types:
                continue

        groups.setdefault((component, build_type), []).append(task)

    tasks_for_all_components = [
        task for task in tasks
        if task.attributes.get('component') == 'all'
        # We just want to depend on the task that waits on all chunks. This way
        # we have a single dependency for that kind
        and task.attributes.get("is_final_chunked_task", True)
    ]
    for (_, build_type), tasks in groups.iteritems():
        tasks.extend([
            task for task in tasks_for_all_components
            if task.attributes.get('build-type') == build_type
        ])

    return groups


@group_by('build-type')
def build_type_grouping(config, tasks):
    groups = {}
    only_build_types = config.get("only-for-build-types")
    for task in tasks:
        if task.kind not in config.get('kind-dependencies', []):
            continue

        # We just want to depend on the task that waits on all chunks. This way
        # we have a single dependency for that kind
        if not task.attributes.get("is_final_chunked_task", True):
            continue

        build_type = task.attributes.get('build-type')
        # Skip only_ and build_types that don't match
        if only_build_types:
            if not build_type or build_type not in only_build_types:
                continue

        groups.setdefault(build_type, []).append(task)

    return groups
