"""物料目录的 MongoDB 存储：每个组件一条记录，目录版本放在元数据记录中，
多个物料共用的字段分组单独存放，每个分组一条记录"""

from loguru import logger
from pymongo.asynchronous.database import AsyncDatabase

from app.resources.component import set_catalog_cache
from app.schemas.component_resource import ComponentCatalog

# 元数据记录的 _id，组件记录的 _id 为组件 key
META_ID = "__catalog__"


class MongoMaterialRepository:
    def __init__(self, db: AsyncDatabase, prefix: str = ""):
        # 集合名前缀用于测试隔离
        self._materials = db.get_collection(f"{prefix}materials")
        self._field_groups = db.get_collection(f"{prefix}material_field_groups")

    async def load_all(self) -> ComponentCatalog | None:
        # 没有元数据记录视为尚未导入，由调用方决定回退方式
        meta = await self._materials.find_one({"_id": META_ID})
        if meta is None:
            return None
        documents = await self._materials.find({"_id": {"$ne": META_ID}}).to_list()
        groups = await self._field_groups.find({}).to_list()
        return ComponentCatalog.model_validate(
            {
                "version": meta["version"],
                "components": _ordered(documents),
                "field_groups": _ordered(groups),
            }
        )

    async def replace_all(self, catalog: ComponentCatalog) -> None:
        # 整体替换目录，供导入脚本使用；order 保持源文件中的顺序
        for collection, items in (
            (self._materials, catalog.components),
            (self._field_groups, catalog.field_groups),
        ):
            await collection.delete_many({})
            if items:
                await collection.insert_many(_documents(items))
        await self._materials.insert_one({"_id": META_ID, "version": catalog.version})


def _documents(items) -> list[dict]:
    # 记录 _id 为物料或分组的 key
    return [
        {**item.model_dump(mode="json", by_alias=True), "_id": item.key, "order": index}
        for index, item in enumerate(items)
    ]


def _ordered(documents: list[dict]) -> list[dict]:
    return [
        {key: value for key, value in item.items() if key not in ("_id", "order")}
        for item in sorted(documents, key=lambda item: item.get("order", 0))
    ]


async def warm_material_cache(db: AsyncDatabase | None) -> ComponentCatalog | None:
    """启动时把物料目录从 MongoDB 载入进程缓存；未启用或尚未导入时目录为空，不回退读文件"""
    catalog = await MongoMaterialRepository(db).load_all() if db is not None else None
    if catalog is None:
        logger.error(
            "物料目录未载入：{}，新增、更换组件等需要物料的修改将无法执行",
            "未配置 MONGODB_URI" if db is None else "materials 集合尚未导入",
        )
    else:
        logger.info("已从 MongoDB 加载物料 {} 个", len(catalog.components))
    set_catalog_cache(catalog)
    return catalog