from dataclasses import dataclass
from pathlib import Path

import aiosqlite
from loguru import logger

from konabot.common.database import DatabaseManager
from konabot.common.path import DATA_PATH


PATH_THISFOLDER = Path(__file__).parent

SQL_CHECK_EXISTS = (PATH_THISFOLDER / "./check_migrate_version_exists.sql").read_text()
SQL_CREATE_TABLE = (PATH_THISFOLDER / "./create_migrate_version_table.sql").read_text()
SQL_GET_MIGRATE_VERSION = (PATH_THISFOLDER / "get_migrate_version.sql").read_text()
SQL_UPDATE_VERSION = (PATH_THISFOLDER / "./update_migrate_version.sql").read_text()

db = DatabaseManager(DATA_PATH / "perm.sqlite3")


@dataclass
class Migration:
    upgrade: str | Path
    downgrade: str | Path

    def get_upgrade_script(self) -> str:
        if isinstance(self.upgrade, Path):
            return self.upgrade.read_text()
        return self.upgrade

    def get_downgrade_script(self) -> str:
        if isinstance(self.downgrade, Path):
            return self.downgrade.read_text()
        return self.downgrade


migrations = [
    Migration(
        PATH_THISFOLDER / "./mu1_create_permsys_table.sql",
        PATH_THISFOLDER / "./md1_remove_permsys_table.sql",
    ),
]


TARGET_VERSION = len(migrations)


async def get_current_version(conn: aiosqlite.Connection) -> int:
    cursor = await conn.execute(SQL_CHECK_EXISTS)
    count = await cursor.fetchone()
    assert count is not None
    if count[0] < 1:
        logger.info("权限系统数据表不存在，现在创建表")
        await conn.executescript(SQL_CREATE_TABLE)
        await conn.commit()
        return 0
    cursor = await conn.execute(SQL_GET_MIGRATE_VERSION)
    row = await cursor.fetchone()
    if row is None:
        return 0
    return row[0]


async def execute_migration(
    conn: aiosqlite.Connection,
    version: int = TARGET_VERSION,
    migrations: list[Migration] = migrations,
):
    now_version = await get_current_version(conn)
    while now_version < version:
        migration = migrations[now_version]
        await conn.executescript(migration.get_upgrade_script())
        now_version += 1
        await conn.execute(SQL_UPDATE_VERSION, (now_version,))
        await conn.commit()
    while now_version > version:
        migration = migrations[now_version - 1]
        await conn.executescript(migration.get_downgrade_script())
        now_version -= 1
        await conn.execute(SQL_UPDATE_VERSION, (now_version,))
        await conn.commit()