# Copyright 2024 The Debusine Developers
# See the AUTHORS file at the top-level directory of this distribution
#
# This file is part of Debusine. It is subject to the license terms
# in the LICENSE file found in the top-level directory of this
# distribution. No part of Debusine, including this file, may be copied,
# modified, propagated, or distributed except according to the terms
# contained in the LICENSE file.

"""Server-side task to update a debian:suite-lintian collection."""

import copy
from collections import defaultdict
from typing import Any

from django.db.models import QuerySet

from debusine.artifacts.models import ArtifactCategory, CollectionCategory
from debusine.db.models import Artifact, CollectionItem, WorkRequest
from debusine.server.tasks.models import UpdateSuiteLintianCollectionData
from debusine.server.tasks.update_derived_collection import (
    UpdateDerivedCollection,
)
from debusine.tasks.models import EventReactions, LintianData


class UpdateSuiteLintianCollection(
    UpdateDerivedCollection[UpdateSuiteLintianCollectionData]
):
    """Task that updates a debian:suite-lintian collection from debian:suite."""

    TASK_VERSION = 1

    BASE_COLLECTION_CATEGORIES = (CollectionCategory.SUITE,)
    DERIVED_COLLECTION_CATEGORIES = (CollectionCategory.SUITE_LINTIAN,)

    def find_expected_derived_items(
        self, relevant_base_items: QuerySet[CollectionItem]
    ) -> dict[str, set[int]]:
        """
        Find the derived item names that should exist given these base items.

        The returned dictionary maps derived item names to sets of base item
        IDs.
        """
        # First, group the base items by source name, source version, and
        # architecture.
        derived_items_by_arch: dict[str, dict[str, set[int]]] = defaultdict(
            lambda: defaultdict(set)
        )
        for item in relevant_base_items:
            if item.category == ArtifactCategory.SOURCE_PACKAGE:
                source_name = item.data["package"]
                source_version = item.data["version"]
                architecture = "source"
            else:
                assert item.category == ArtifactCategory.BINARY_PACKAGE
                source_name = item.data["srcpkg_name"]
                source_version = item.data["srcpkg_version"]
                architecture = item.data["architecture"]
            derived_items_by_arch[f"{source_name}_{source_version}"][
                architecture
            ].add(item.id)

        # Use the grouped base items to decide which derived items we need.
        # We only need a separate `*_source` item if we have a source
        # package with no corresponding binary packages; otherwise, source
        # packages are base items for each per-architecture derived item.
        derived_items = defaultdict(set)
        for (
            source_name_version,
            item_ids_by_arch,
        ) in derived_items_by_arch.items():
            for architecture, item_ids in item_ids_by_arch.items():
                if architecture != "source":
                    derived_items[f"{source_name_version}_{architecture}"] = (
                        item_ids | item_ids_by_arch.get("source", set())
                    )
            if item_ids_by_arch.keys() == {"source"}:
                derived_items[f"{source_name_version}_source"] = (
                    item_ids_by_arch["source"]
                )

        return derived_items

    def make_child_work_request(
        self,
        base_item_ids: set[int],
        child_task_data: dict[str, Any] | None,
        force: bool,
    ) -> WorkRequest | None:
        """Make a work request to create a new derived item with this name."""
        assert self.work_request is not None
        assert self.workspace is not None

        task_data: dict[str, Any] = copy.deepcopy(child_task_data or {})

        base_artifacts_by_category = defaultdict(set)
        for artifact in Artifact.objects.filter(
            collection_items__id__in=base_item_ids
        ).only("id", "category"):
            base_artifacts_by_category[artifact.category].add(artifact.id)
        source_artifact_ids = sorted(
            base_artifacts_by_category.get(
                ArtifactCategory.SOURCE_PACKAGE, set()
            )
        )
        binary_artifacts_ids = sorted(
            base_artifacts_by_category.get(
                ArtifactCategory.BINARY_PACKAGE, set()
            )
        )
        if not source_artifact_ids and not binary_artifacts_ids:
            raise ValueError(
                f"Base items must include at least one "
                f"{ArtifactCategory.SOURCE_PACKAGE} or "
                f"{ArtifactCategory.BINARY_PACKAGE} artifact"
            )
        if len(source_artifact_ids) > 1:
            raise ValueError(
                f"Base items must include at most one "
                f"{ArtifactCategory.SOURCE_PACKAGE} artifact: "
                f"{source_artifact_ids}"
            )
        task_data.setdefault("input", {})
        if source_artifact_ids:
            task_data["input"]["source_artifact"] = source_artifact_ids[0]
        task_data["input"]["binary_artifacts"] = [
            artifact_id for artifact_id in binary_artifacts_ids
        ]

        params: dict[str, Any] = {
            "task_name": "lintian",
            "task_data": LintianData(**task_data).dict(exclude_unset=True),
            "workspace": self.workspace,
            "created_by": self.work_request.created_by,
            "parent": self.work_request,
            "event_reactions_json": EventReactions.parse_obj(
                {
                    "on_success": [
                        {
                            "action": "update-collection-with-artifacts",
                            "artifact_filters": {
                                "category": ArtifactCategory.LINTIAN
                            },
                            "collection": self.data.derived_collection,
                        }
                    ]
                }
            ).dict(exclude_unset=True),
        }
        if force or not WorkRequest.objects.filter(**params).exists():
            return WorkRequest.objects.create(**params)
        else:
            return None

    def get_label(self) -> str:
        """Return the task label."""
        return "sync derived lintian collection"
