from dataclasses import dataclass
import math
from pathlib import Path

import aiosqlite

from konabot.common.pager import PagerQuery, PagerResult

from .entity import PermEntity


def s(p: str):
    """读取 SQL 文件内容。

    Args:
        p: SQL 文件名（相对于当前文件所在目录的 sql/ 子目录）。

    Returns:
        SQL 文件的内容字符串。
    """
    return (Path(__file__).parent / "./sql/" / p).read_text()


@dataclass
class PermRepo:
    """权限实体存储库，负责与数据库交互管理权限实体。

    Attributes:
        conn: aiosqlite 数据库连接对象。
    """

    conn: aiosqlite.Connection

    async def create_entity(self, entity: PermEntity) -> int:
        """创建新的权限实体并返回其 ID。

        Args:
            entity: 要创建的权限实体对象。

        Returns:
            新创建实体的数据库 ID。

        Raises:
            AssertionError: 如果创建后无法获取实体 ID。
        """
        try:
            await self.conn.execute(
                s("create_entity.sql"),
                (entity.platform, entity.entity_type, entity.external_id),
            )
            await self.conn.commit()
        except Exception:
            await self.conn.rollback()
            raise
        eid = await self._get_entity_id_or_none(entity)
        assert eid is not None
        return eid

    async def _get_entity_id_or_none(self, entity: PermEntity) -> int | None:
        """查询实体 ID，如果不存在则返回 None。

        Args:
            entity: 要查询的权限实体对象。

        Returns:
            实体 ID，如果不存在则返回 None。
        """
        res = await self.conn.execute(
            s("get_entity_id.sql"),
            (entity.platform, entity.entity_type, entity.external_id),
        )
        row = await res.fetchone()
        if row is None:
            return None
        return row[0]

    async def get_entity_id(self, entity: PermEntity) -> int:
        """获取实体 ID，如果不存在则自动创建。

        Args:
            entity: 权限实体对象。

        Returns:
            实体的数据库 ID。
        """
        eid = await self._get_entity_id_or_none(entity)
        if eid is None:
            return await self.create_entity(entity)
        return eid

    async def get_perm_info(self, entity: PermEntity, config_key: str) -> bool | None:
        """获取实体的权限配置信息。

        Args:
            entity: 权限实体对象。
            config_key: 配置项的键名。

        Returns:
            配置值（True/False），如果不存在则返回 None。
        """
        eid = await self.get_entity_id(entity)
        res = await self.conn.execute(
            s("get_perm_info.sql"),
            (eid, config_key),
        )
        row = await res.fetchone()
        if row is None:
            return None
        return bool(row[0])

    async def update_perm_info(
        self, entity: PermEntity, config_key: str, value: bool | None
    ):
        """更新实体的权限配置信息。

        Args:
            entity: 权限实体对象。
            config_key: 配置项的键名。
            value: 要设置的配置值（True/False/None）。
        """
        eid = await self.get_entity_id(entity)
        try:
            await self.conn.execute(s("update_perm_info.sql"), (eid, config_key, value))
            await self.conn.commit()
        except Exception:
            await self.conn.rollback()
            raise

    async def get_entity_id_batch(
        self, entities: list[PermEntity]
    ) -> dict[PermEntity, int]:
        """批量获取 Entity 的 entity_id

        Args:
            entities: PermEntity 列表

        Returns:
            字典，键为 PermEntity，值为对应的 ID
        """

        # for entity in entities:
        #     await self.conn.execute(
        #         s("create_entity.sql"),
        #         (entity.platform, entity.entity_type, entity.external_id),
        #     )
        try:
            await self.conn.executemany(
                s("create_entity.sql"),
                [(e.platform, e.entity_type, e.external_id) for e in entities],
            )
            await self.conn.commit()
        except Exception:
            await self.conn.rollback()
            raise
        val_placeholders = ", ".join(["(?, ?, ?)"] * len(entities))
        params = []
        for e in entities:
            params.extend([e.platform, e.entity_type, e.external_id])
        cursor = await self.conn.execute(
            f"""
                SELECT id, platform, entity_type, external_id
                FROM perm_entity
                WHERE (platform, entity_type, external_id) IN (VALUES {val_placeholders});
            """,
            params,
        )
        rows = await cursor.fetchall()
        return {PermEntity(row[1], row[2], row[3]): row[0] for row in rows}

    async def get_perm_info_batch(
        self, entities: list[PermEntity], config_keys: list[str]
    ) -> dict[tuple[PermEntity, str], bool]:
        """批量获取权限信息

        Args:
            entities: PermEntity 列表
            config_keys: 查询的键列表

        Returns:
            字典，键是 PermEntity 和 config_key 的元组，值是布尔，过滤掉所有空值
        """
        entity_ids = {
            v: k for k, v in (await self.get_entity_id_batch(entities)).items()
        }
        placeholders1 = ", ".join("?" * len(entity_ids))
        placeholders2 = ", ".join("?" * len(config_keys))
        sql = f"""
            SELECT entity_id, config_key, value
            FROM perm_info
            WHERE entity_id IN ({placeholders1})
              AND config_key IN ({placeholders2})
              AND value IS NOT NULL;
        """

        params = tuple(entity_ids.keys()) + tuple(config_keys)
        cursor = await self.conn.execute(sql, params)
        rows = await cursor.fetchall()

        return {(entity_ids[row[0]], row[1]): bool(row[2]) for row in rows}

    async def list_perm_info_batch(
        self, entities: list[PermEntity], pager: PagerQuery
    ) -> PagerResult[tuple[PermEntity, str, bool]]:
        """批量获取某个实体的权限信息

        Args:
            entities: PermEntity 列表
            pager: PagerQuery 对象，即分页要求

        Returns:
            字典，键是 PermEntity，值是权限条目和布尔的元组，过滤掉所有空值
        """
        entity_to_id = await self.get_entity_id_batch(entities)
        id_to_entity = {v: k for k, v in entity_to_id.items()}
        ordered_ids = [entity_to_id[e] for e in entities if e in entity_to_id]

        placeholders = ", ".join("?" * len(ordered_ids))
        order_by_cases = " ".join([f"WHEN ? THEN {i}" for i in range(len(ordered_ids))])

        pagecount_sql = f"SELECT COUNT(*) FROM perm_info WHERE entity_id IN ({placeholders}) AND value IS NOT NULL;"
        count_cursor = await self.conn.execute(pagecount_sql, tuple(ordered_ids))
        total_count = (await count_cursor.fetchone() or (0,))[0]

        sql = f"""
            SELECT entity_id, config_key, value
            FROM perm_info
            WHERE entity_id IN ({placeholders})
              AND value IS NOT NULL
            ORDER BY
                (CASE entity_id {order_by_cases} END) ASC,
                config_key ASC
            LIMIT ?
            OFFSET ?;
        """

        params = (
            tuple(ordered_ids)
            + tuple(ordered_ids)
            + (
                pager.page_size,
                (pager.page_index - 1) * pager.page_size,
            )
        )
        cursor = await self.conn.execute(sql, params)
        rows = await cursor.fetchall()

        # return {entity_ids[row[0]]: (row[1], bool(row[2])) for row in rows}
        return PagerResult(
            data=[(id_to_entity[row[0]], row[1], row[2]) for row in rows],
            success=True,
            message="",
            page_count=math.ceil(total_count / pager.page_size),
            query=pager,
        )