// packages/backend/src/repositories/proxy.repository.ts
import { Database, Statement } from 'sqlite3';
// Import new async helpers and the instance getter
import { getDbInstance, runDb, getDb as getDbRow, allDb } from '../database/connection';

// Remove top-level db instance
// const db = getDb();

// 定义 Proxy 类型 (可以共享到 types 文件)
export interface ProxyData {
    id: number;
    name: string;
    type: 'SOCKS5' | 'HTTP';
    host: string;
    port: number;
    username?: string | null;
    auth_method: 'none' | 'password' | 'key';
    encrypted_password?: string | null;
    encrypted_private_key?: string | null;
    encrypted_passphrase?: string | null;
    created_at: number;
    updated_at: number;
}

// Define the expected row structure from the database if it matches ProxyData
type DbProxyRow = ProxyData;

/**
 * 根据名称、类型、主机和端口查找代理
 */
export const findProxyByNameTypeHostPort = async (name: string, type: string, host: string, port: number): Promise<{ id: number } | undefined> => {
    const sql = `SELECT id FROM proxies WHERE name = ? AND type = ? AND host = ? AND port = ?`;
    try {
        const db = await getDbInstance();
        const row = await getDbRow<{ id: number }>(db, sql, [name, type, host, port]);
        return row;
    } catch (err: any) {
        console.error(`Repository: 查找代理时出错 (name=${name}, type=${type}, host=${host}, port=${port}):`, err.message);
        throw new Error(`查找代理时出错: ${err.message}`);
    }
};

/**
 * 创建新代理
 */
export const createProxy = async (data: Omit<ProxyData, 'id' | 'created_at' | 'updated_at'>): Promise<number> => {
    const now = Math.floor(Date.now() / 1000);
    const sql = `INSERT INTO proxies (name, type, host, port, username, auth_method, encrypted_password, encrypted_private_key, encrypted_passphrase, created_at, updated_at)
             VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`;
    const params = [
        data.name, data.type, data.host, data.port,
        data.username || null,
        data.auth_method || 'none',
        data.encrypted_password || null,
        data.encrypted_private_key || null,
        data.encrypted_passphrase || null,
        now, now
    ];
    try {
        const db = await getDbInstance();
        const result = await runDb(db, sql, params);
        // Ensure lastID is valid before returning
        if (typeof result.lastID !== 'number' || result.lastID <= 0) {
             throw new Error('创建代理后未能获取有效的 lastID');
        }
        return result.lastID;
    } catch (err: any) {
        console.error('Repository: 创建代理时出错:', err.message);
        // Handle potential UNIQUE constraint errors if needed (e.g., on name)
        throw new Error(`创建代理时出错: ${err.message}`);
    }
};

/**
 * 获取所有代理
 */
export const findAllProxies = async (): Promise<ProxyData[]> => {
    const sql = `SELECT * FROM proxies ORDER BY name ASC`;
    try {
        const db = await getDbInstance();
        const rows = await allDb<DbProxyRow>(db, sql);
        return rows;
    } catch (err: any) {
        console.error('Repository: 查询代理列表时出错:', err.message);
        throw new Error('获取代理列表失败');
    }
};

/**
 * 根据 ID 获取单个代理
 */
export const findProxyById = async (id: number): Promise<ProxyData | null> => {
     const sql = `SELECT * FROM proxies WHERE id = ?`;
     try {
        const db = await getDbInstance();
        const row = await getDbRow<DbProxyRow>(db, sql, [id]);
        return row || null;
     } catch (err: any) {
        console.error(`Repository: 查询代理 ${id} 时出错:`, err.message);
        throw new Error('获取代理信息失败');
     }
 };


/**
 * 更新代理信息
 */
export const updateProxy = async (id: number, data: Partial<Omit<ProxyData, 'id' | 'created_at'>>): Promise<boolean> => {
    const fieldsToUpdate: { [key: string]: any } = { ...data };
    const params: any[] = [];

    // Remove fields that should not be updated directly
    delete fieldsToUpdate.id;
    delete fieldsToUpdate.created_at;
    // updated_at will be set explicitly

    fieldsToUpdate.updated_at = Math.floor(Date.now() / 1000);

    const setClauses = Object.keys(fieldsToUpdate).map(key => `${key} = ?`).join(', ');
    Object.values(fieldsToUpdate).forEach(value => params.push(value ?? null));

    if (!setClauses) {
        console.warn(`[Repository] updateProxy called for ID ${id} with no fields to update.`);
        return false; // Nothing to update
    }

    params.push(id); // Add the ID for the WHERE clause

    const sql = `UPDATE proxies SET ${setClauses} WHERE id = ?`;

    try {
        const db = await getDbInstance();
        const result = await runDb(db, sql, params);
        return result.changes > 0;
    } catch (err: any) {
        console.error(`Repository: 更新代理 ${id} 时出错:`, err.message);
        // Handle potential UNIQUE constraint errors if needed
        throw new Error('更新代理记录失败');
    }
};

/**
 * 删除代理
 */
export const deleteProxy = async (id: number): Promise<boolean> => {
    // Note: connections table proxy_id foreign key has ON DELETE SET NULL.
    const sql = `DELETE FROM proxies WHERE id = ?`;
    try {
        const db = await getDbInstance();
        const result = await runDb(db, sql, [id]);
        return result.changes > 0;
    } catch (err: any) {
        console.error(`Repository: 删除代理 ${id} 时出错:`, err.message);
        throw new Error('删除代理记录失败');
    }
};