/**
 * 管理员数据迁移脚本 - Node.js
 * Feature: database-migration, Property 2: 数据记录数一致性
 * Validates: Requirements 10.1
 * 
 * 源表: MySQL admin (3 条记录)
 * 目标表: SQL Server admins
 * 
 * 注意: 管理日志表(admin_login_logs, admin_operation_logs)仅保留结构，不迁移数据
 */

const mysql = require('mysql2/promise');
const sql = require('mssql');

// MySQL 配置
const mysqlConfig = {
    host: '192.168.195.16',
    port: 1887,
    user: 'root',
    password: 'Dbt@com@123',
    database: 'youdas',
    charset: 'utf8mb4'
};

// SQL Server 配置
const sqlServerConfig = {
    server: '192.168.195.15',
    port: 1433,
    user: 'sa',
    password: 'Dbt@com@123',
    database: 'honey_box',
    options: {
        encrypt: false,
        trustServerCertificate: true
    }
};

// Unix时间戳转换为 SQL Server DATETIME2 格式
function unixToDatetime(timestamp) {
    if (!timestamp || timestamp === 0) {
        return null;
    }
    const date = new Date(timestamp * 1000);
    return date.toISOString().slice(0, 23).replace('T', ' ');
}

// 转义SQL字符串
function escapeString(str) {
    if (str === null || str === undefined) return 'NULL';
    return "N'" + String(str).replace(/'/g, "''") + "'";
}

// 格式化日期时间
function formatDatetime(dt) {
    if (!dt) return 'NULL';
    return "'" + dt + "'";
}

// 获取已迁移的管理员ID列表
async function getMigratedIds(pool) {
    const result = await pool.request().query('SELECT id FROM admins');
    return new Set(result.recordset.map(r => r.id));
}

// 插入单条管理员数据
async function insertAdmin(pool, admin) {
    const createdAt = unixToDatetime(admin.addtime) || new Date().toISOString().slice(0, 23).replace('T', ' ');
    const updatedAt = unixToDatetime(admin.update_time) || createdAt;
    const getTime = unixToDatetime(admin.get_time) || createdAt;
    
    const sqlStatement = `
SET IDENTITY_INSERT admins ON;
INSERT INTO admins (
    id, username, nickname, password, qid, status, get_time,
    random, token, admin_id, created_at, updated_at
) VALUES (
    ${admin.id}, 
    ${escapeString(admin.username)}, 
    ${escapeString(admin.nickname)}, 
    ${escapeString(admin.password)}, 
    ${admin.qid || 'NULL'}, 
    ${admin.status || 0}, 
    ${formatDatetime(getTime)},
    ${escapeString(admin.random)}, 
    ${escapeString(admin.token)}, 
    ${admin.admin_id || 0}, 
    ${formatDatetime(createdAt)}, 
    ${formatDatetime(updatedAt)}
);
SET IDENTITY_INSERT admins OFF;`;
    
    await pool.request().batch(sqlStatement);
}

async function main() {
    console.log('========================================');
    console.log('管理员数据迁移脚本 - Node.js');
    console.log('========================================\n');
    
    let mysqlConn = null;
    let sqlPool = null;
    
    try {
        // 连接 MySQL
        console.log('正在连接 MySQL...');
        mysqlConn = await mysql.createConnection(mysqlConfig);
        console.log('MySQL 连接成功\n');
        
        // 连接 SQL Server
        console.log('正在连接 SQL Server...');
        sqlPool = await sql.connect(sqlServerConfig);
        console.log('SQL Server 连接成功\n');
        
        // 获取已迁移的ID
        console.log('正在获取已迁移的管理员ID...');
        const migratedIds = await getMigratedIds(sqlPool);
        console.log(`已迁移管理员数: ${migratedIds.size}\n`);
        
        // 从 MySQL 获取所有管理员数据
        console.log('正在从 MySQL 读取管理员数据...');
        const [rows] = await mysqlConn.execute(`
            SELECT id, username, nickname, password, qid, status, get_time,
                   random, token, admin_id, addtime, update_time
            FROM admin
            ORDER BY id
        `);
        console.log(`MySQL 管理员总数: ${rows.length}\n`);
        
        // 过滤出未迁移的管理员
        const adminsToMigrate = rows.filter(admin => !migratedIds.has(admin.id));
        console.log(`待迁移管理员数: ${adminsToMigrate.length}\n`);
        
        if (adminsToMigrate.length === 0) {
            console.log('所有管理员数据已迁移完成！');
        } else {
            // 逐条迁移（数据量小，无需批量）
            let totalInserted = 0;
            
            for (const admin of adminsToMigrate) {
                try {
                    await insertAdmin(sqlPool, admin);
                    totalInserted++;
                    console.log(`已迁移管理员: ${admin.id} - ${admin.username}`);
                } catch (err) {
                    console.error(`插入管理员 ${admin.id} 失败:`, err.message);
                }
            }
            
            console.log(`\n迁移完成！共插入 ${totalInserted} 条记录`);
        }
        
        // 验证迁移结果
        console.log('\n========================================');
        console.log('迁移结果验证');
        console.log('========================================');
        
        const [mysqlCount] = await mysqlConn.execute('SELECT COUNT(*) as count FROM admin');
        const sqlResult = await sqlPool.request().query('SELECT COUNT(*) as count FROM admins');
        
        console.log(`MySQL admin 表记录数: ${mysqlCount[0].count}`);
        console.log(`SQL Server admins 表记录数: ${sqlResult.recordset[0].count}`);
        
        if (mysqlCount[0].count === sqlResult.recordset[0].count) {
            console.log('\n✅ 数据迁移完成，记录数一致！');
        } else {
            console.log(`\n⚠️ 记录数不一致，差异: ${mysqlCount[0].count - sqlResult.recordset[0].count}`);
        }
        
        // 显示迁移后的数据
        console.log('\n========================================');
        console.log('迁移后的管理员数据');
        console.log('========================================');
        
        const adminsResult = await sqlPool.request().query('SELECT id, username, nickname, status FROM admins ORDER BY id');
        for (const admin of adminsResult.recordset) {
            console.log(`ID: ${admin.id}, 用户名: ${admin.username}, 昵称: ${admin.nickname}, 状态: ${admin.status}`);
        }
        
    } catch (err) {
        console.error('迁移过程中发生错误:', err);
        process.exit(1);
    } finally {
        // 关闭连接
        if (mysqlConn) await mysqlConn.end();
        if (sqlPool) await sqlPool.close();
    }
}

main();