#  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/.

import logging
import os
import sys

from redo import retry
from taskgraph.decision import (
    _determine_more_accurate_base_ref,
    _determine_more_accurate_base_rev,
    _get_env_prefix,
)
from taskgraph.taskgraph import TaskGraph
from taskgraph.util.taskcluster import get_artifact
from taskgraph.util.vcs import get_repository

from gecko_taskgraph.util.backstop import is_backstop
from gecko_taskgraph.util.partials import populate_release_history
from gecko_taskgraph.util.taskgraph import (
    find_decision_task,
    find_existing_tasks_from_previous_kinds,
)

from . import COMM
from comm_taskgraph.parameters import get_defaults

logger = logging.getLogger(__name__)

BALROG_PRODUCT = "Thunderbird"

# Backstop defaults
BACKSTOP_TIME_INTERVAL = 60 * 22  # minutes
INTEGRATION_PROJECTS = {"comm-central"}

PER_PROJECT_PARAMETERS = {
    "ash": {
        "target_tasks_method": "ash_tasks",
    },
    "jamun": {
        "target_tasks_method": "nightly_desktop",
        "release_type": "nightly",
    },
    "try-comm-central": {
        "enable_always_target": True,
        "target_tasks_method": "try_cc_tasks",
    },
    "comm-central": {
        "target_tasks_method": "comm_central_tasks",
        "release_type": "nightly",
    },
    "comm-beta": {
        "target_tasks_method": "mozilla_beta_tasks",
        "release_type": "beta",
    },
    "comm-esr115": {
        "target_tasks_method": "mozilla_esr115_tasks",
        "release_type": "release",
    },
}

CRON_OPTIONS = {
    "nightly_desktop": {
        "existing_tasks": lambda parameters, graph_config: get_existing_tasks(
            parameters, graph_config
        ),
        "release_history": lambda parameters, graph_config: populate_release_history(
            BALROG_PRODUCT, parameters["project"]
        ),
    }
}


def get_decision_parameters(graph_config, parameters):
    logger.info("{}.get_decision_parameters called".format(__name__))

    # Apply default values for all Thunderbird CI projects
    parameters.update(get_defaults(graph_config.vcs_root))

    # If the target method is nightly, we should build partials. This means
    # knowing what has been released previously.
    # An empty release_history is fine, it just means no partials will be built
    project = parameters["project"]

    if project in PER_PROJECT_PARAMETERS:
        # Upstream will set target_tasks_method to "default" when nothing is set
        if parameters["target_tasks_method"] == "default":
            del parameters["target_tasks_method"]

        # If running from .cron.yml, do not overwrite existing parameters
        update_parameters = [
            (_k, _v)
            for _k, _v in PER_PROJECT_PARAMETERS[project].items()
            if _k not in parameters or not parameters[_k]
        ]
        parameters.update(update_parameters)
        logger.info("project parameters set for project {} from {}.".format(project, __file__))
    else:
        # Projects without a target_tasks_method should not exist for Thunderbird CI
        raise Exception("No target_tasks_method is defined for project {}.".format(project))

    del parameters["backstop"]
    parameters["backstop"] = is_backstop(
        parameters,
        trust_domain="comm",
        time_interval=BACKSTOP_TIME_INTERVAL,
        integration_projects=INTEGRATION_PROJECTS,
    )
    for n in (
        "COMM_BASE_REPOSITORY",
        "COMM_BASE_REV",
        "COMM_HEAD_REPOSITORY",
        "COMM_HEAD_REV",
        "COMM_HEAD_REF",
    ):
        val = os.environ.get(n, "")
        parameters[n.lower()] = val

    repo_path = COMM
    repo = get_repository(repo_path)
    logger.info("Determining comm_base_ref...")
    parameters["comm_base_ref"] = _determine_more_accurate_base_ref(
        repo,
        candidate_base_ref="",
        head_ref=parameters.get("comm_head_ref"),
        base_rev=parameters.get("comm_base_rev"),
    )
    logger.info("Determining comm_base_rev...")
    parameters["comm_base_rev"] = _determine_more_accurate_base_rev(
        repo,
        base_ref=parameters["comm_base_ref"],
        candidate_base_rev=parameters.get("comm_base_rev"),
        head_rev=parameters.get("comm_head_rev"),
        env_prefix=_get_env_prefix(graph_config),
    )

    parameters.setdefault("release_history", dict())
    if parameters.get("tasks_for", "") == "cron":
        for key, _callable in CRON_OPTIONS.get(parameters["target_tasks_method"], {}).items():
            result = _callable(parameters, graph_config)
            parameters[key] = result


def get_existing_tasks(parameters, graph_config):
    """
    Find the decision task corresponding to the on-push graph, and return
    a mapping of labels to task-ids from it.
    """
    try:
        decision_task = retry(
            find_decision_task,
            args=(parameters, graph_config),
            attempts=4,
            sleeptime=5 * 60,
        )
    except Exception:
        logger.exception("Didn't find existing push task.")
        sys.exit(1)

    _, task_graph = TaskGraph.from_json(get_artifact(decision_task, "public/full-task-graph.json"))
    return find_existing_tasks_from_previous_kinds(task_graph, [decision_task], [])