"""mark_asset_used_for_generation 深度补充单测.

补全边界场景：空 metadata、None metadata、last_used_at 格式、
review_status 已有值不覆盖、多次调用递增。
"""

from __future__ import annotations

from datetime import datetime, timezone

from worker_app.core.asset_usage import mark_asset_used_for_generation

from packages.domain import Asset, AssetStatus


def _asset() -> Asset:
    return Asset.create(
        project_id="project-1",
        library_id="library-1",
        name="video.mp4",
        storage_key="uploads/video.mp4",
        mime_type="video/mp4",
        file_size=1024,
        status=AssetStatus.READY,
    )


class TestMarkAssetUsedForGeneration:
    """mark_asset_used_for_generation 深度测试."""

    def test_first_use_sets_count_to_1(self):
        """首次使用，use_count 从 0 变 1."""
        asset = _asset()
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 1

    def test_increments_existing_count(self):
        """已有计数时递增."""
        asset = _asset()
        asset.metadata = {"generation_use_count": 5}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 6

    def test_zero_count_increments_to_1(self):
        """计数为 0 时递增到 1."""
        asset = _asset()
        asset.metadata = {"generation_use_count": 0}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 1

    def test_empty_metadata_still_works(self):
        """空 dict metadata 也能正常工作."""
        asset = _asset()
        asset.metadata = {}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 1
        assert asset.metadata["review_status"] == "pending_review"
        assert "last_used_at" in asset.metadata

    def test_none_metadata_field_defaults_to_0(self):
        """metadata 中 generation_use_count 为 None 时按 0 处理."""
        asset = _asset()
        asset.metadata = {"generation_use_count": None}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 1

    def test_string_count_gets_casted(self):
        """字符串类型的 use_count 通过 int() 转换."""
        asset = _asset()
        asset.metadata = {"generation_use_count": "3"}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 4

    def test_preserves_other_metadata_fields(self):
        """不覆盖 metadata 中的其他字段."""
        asset = _asset()
        asset.metadata = {
            "generation_use_count": 1,
            "custom_field": "value",
            "tags": ["a", "b"],
        }
        mark_asset_used_for_generation(asset)
        assert asset.metadata["custom_field"] == "value"
        assert asset.metadata["tags"] == ["a", "b"]
        assert asset.metadata["generation_use_count"] == 2

    def test_review_status_pending_when_not_set(self):
        """review_status 未设置时设为 pending_review."""
        asset = _asset()
        asset.metadata = {}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["review_status"] == "pending_review"

    def test_review_status_not_overwritten_if_present(self):
        """review_status 已有值时不覆盖."""
        asset = _asset()
        asset.metadata = {"review_status": "approved"}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["review_status"] == "approved"

    def test_review_status_empty_string_considered_falsy(self):
        """review_status 为空字符串时视为 falsy，设置为 pending_review."""
        asset = _asset()
        asset.metadata = {"review_status": ""}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["review_status"] == "pending_review"

    def test_last_used_at_is_iso_format(self):
        """last_used_at 是 ISO 格式时间字符串."""
        asset = _asset()
        mark_asset_used_for_generation(asset)
        ts = asset.metadata["last_used_at"]
        # 可以被解析为 ISO 格式
        parsed = datetime.fromisoformat(ts)
        assert parsed.tzinfo is not None  # 带时区

    def test_last_used_at_is_utc(self):
        """last_used_at 是 UTC 时间."""
        asset = _asset()
        before = datetime.now(timezone.utc)
        mark_asset_used_for_generation(asset)
        after = datetime.now(timezone.utc)
        ts = datetime.fromisoformat(asset.metadata["last_used_at"])
        assert before <= ts <= after

    def test_multiple_calls_increment_count(self):
        """多次调用持续递增."""
        asset = _asset()
        mark_asset_used_for_generation(asset)
        mark_asset_used_for_generation(asset)
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == 3

    def test_negative_count_still_increments(self):
        """负数计数（异常数据）也能递增."""
        asset = _asset()
        asset.metadata = {"generation_use_count": -5}
        mark_asset_used_for_generation(asset)
        assert asset.metadata["generation_use_count"] == -4