"""数据库连接管理 - 使用上下文管理器，避免全局单例连接泄漏"""
import os
import aiosqlite
from contextlib import asynccontextmanager
from typing import AsyncIterator
from core.config import settings
from core.log import logger


DB_PATH = os.path.join(settings.base_dir, settings.db_path)


def ensure_db_dir():
    db_dir = os.path.dirname(DB_PATH)
    if db_dir and not os.path.exists(db_dir):
        os.makedirs(db_dir, exist_ok=True)


async def init_db():
    """初始化数据库表结构（支持迁移）"""
    ensure_db_dir()
    async with aiosqlite.connect(DB_PATH) as db:
        await db.execute("PRAGMA journal_mode=WAL")
        await db.execute("PRAGMA synchronous=NORMAL")
        await db.execute("PRAGMA cache_size=-64000")
        await db.execute("PRAGMA temp_store=MEMORY")

        await db.execute("""
            CREATE TABLE IF NOT EXISTS proxies (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                ip TEXT NOT NULL,
                port INTEGER NOT NULL,
                protocol TEXT DEFAULT 'http',
                score INTEGER DEFAULT 10,
                response_time_ms REAL,
                last_check TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                UNIQUE(ip, port)
            )
        """)

        # 迁移：如果旧表缺少 response_time_ms 列，则添加
        try:
            await db.execute("SELECT response_time_ms FROM proxies LIMIT 1")
        except Exception:
            await db.execute("ALTER TABLE proxies ADD COLUMN response_time_ms REAL")
            logger.info("Migrated: added response_time_ms column")

        # 迁移：如果旧表缺少 created_at 列，则添加
        try:
            await db.execute("SELECT created_at FROM proxies LIMIT 1")
        except Exception:
            await db.execute("ALTER TABLE proxies ADD COLUMN created_at TIMESTAMP")
            await db.execute("UPDATE proxies SET created_at = CURRENT_TIMESTAMP WHERE created_at IS NULL")
            logger.info("Migrated: added created_at column")

        await db.execute("CREATE INDEX IF NOT EXISTS idx_score ON proxies(score)")
        await db.execute("CREATE INDEX IF NOT EXISTS idx_protocol ON proxies(protocol)")
        await db.execute("CREATE INDEX IF NOT EXISTS idx_last_check ON proxies(last_check)")
        await db.execute("CREATE INDEX IF NOT EXISTS idx_ip_port ON proxies(ip, port)")

        # 插件设置表
        await db.execute("""
            CREATE TABLE IF NOT EXISTS plugin_settings (
                plugin_id TEXT PRIMARY KEY,
                enabled INTEGER DEFAULT 1,
                config_json TEXT DEFAULT '{}',
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        """)

        # 迁移：为旧版 plugin_settings 表增加 config_json 列
        try:
            await db.execute("SELECT config_json FROM plugin_settings LIMIT 1")
        except Exception:
            await db.execute("ALTER TABLE plugin_settings ADD COLUMN config_json TEXT DEFAULT '{}'")
            logger.info("Migrated: added config_json column to plugin_settings")

        # 验证任务队列表
        await db.execute("""
            CREATE TABLE IF NOT EXISTS validation_tasks (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                ip TEXT NOT NULL,
                port INTEGER NOT NULL,
                protocol TEXT DEFAULT 'http',
                status TEXT DEFAULT 'pending',
                result TEXT,
                response_time_ms REAL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        """)
        await db.execute("CREATE INDEX IF NOT EXISTS idx_validation_status ON validation_tasks(status)")
        await db.execute("CREATE INDEX IF NOT EXISTS idx_validation_created ON validation_tasks(created_at)")

        # 系统设置表
        await db.execute("""
            CREATE TABLE IF NOT EXISTS settings (
                key TEXT PRIMARY KEY,
                value TEXT NOT NULL,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        """)

        await db.commit()
    logger.info("Database initialized")


@asynccontextmanager
async def get_db() -> AsyncIterator[aiosqlite.Connection]:
    """获取数据库连接的异步上下文管理器"""
    ensure_db_dir()
    db = await aiosqlite.connect(DB_PATH)
    try:
        await db.execute("PRAGMA journal_mode=WAL")
        await db.execute("PRAGMA synchronous=NORMAL")
        yield db
    finally:
        await db.close()