import * as readline from 'readline';
import chalk from 'chalk';
import type { Agent } from '../core/agent.js';

export class TerminalUI {
  private agent: Agent;
  private rl: readline.Interface;
  private isClosed = false;

  constructor(agent: Agent) {
    this.agent = agent;
    this.rl = readline.createInterface({
      input: process.stdin,
      output: process.stdout,
      terminal: true,
    });

    // 监听关闭事件
    this.rl.on('close', () => {
      this.isClosed = true;
    });
  }

  // 显示欢迎信息
  private showWelcome(): void {
    console.log(chalk.cyan('\n╔════════════════════════════════════════╗'));
    console.log(chalk.cyan('║') + chalk.bold.white('     🤖 AI Terminal Assistant          ') + chalk.cyan('║'));
    console.log(chalk.cyan('║') + chalk.gray('     Powered by DeepSeek / Claude      ') + chalk.cyan('║'));
    console.log(chalk.cyan('╚════════════════════════════════════════╝\n'));
    console.log(chalk.gray('输入你的问题，或使用以下命令：'));
    console.log(chalk.yellow('  /help') + chalk.gray('  - 显示帮助'));
    console.log(chalk.yellow('  /clear') + chalk.gray(' - 清空对话历史'));
    console.log(chalk.yellow('  /exit') + chalk.gray('  - 退出程序'));
    console.log('');
  }

  // 处理特殊命令
  private handleCommand(input: string): boolean {
    const command = input.toLowerCase().trim();

    switch (command) {
      case '/help':
        console.log(chalk.cyan('\n📖 帮助信息：'));
        console.log(chalk.white('  这是一个 AI 编程助手，可以帮你：'));
        console.log(chalk.gray('  • 读写文件'));
        console.log(chalk.gray('  • 执行 bash 命令'));
        console.log(chalk.gray('  • 搜索代码'));
        console.log(chalk.gray('  • 回答编程问题'));
        console.log('');
        return true;

      case '/clear':
        // clearHistory 现在是异步的
        void this.agent.clearHistory();
        console.log(chalk.green('✓ 对话历史已清空\n'));
        return true;

      case '/exit':
      case '/quit':
        console.log(chalk.cyan('\n👋 再见！\n'));
        this.close();
        process.exit(0);

      default:
        return false;
    }
  }

  // 提问并获取用户输入
  private prompt(): Promise<string> {
    return new Promise((resolve, reject) => {
      if (this.isClosed) {
        reject(new Error('readline closed'));
        return;
      }

      this.rl.question(chalk.green('You > '), (answer) => {
        resolve(answer ?? '');
      });
    });
  }

  // 主循环
  async start(): Promise<void> {
    this.showWelcome();

    while (!this.isClosed) {
      try {
        const input = await this.prompt();

        // 跳过空输入
        if (!input.trim()) {
          continue;
        }

        // 处理命令
        if (input.startsWith('/')) {
          if (this.handleCommand(input)) {
            continue;
          }
        }

        // 发送给 AI
        process.stdout.write(chalk.gray('思考中...'));

        try {
          let isFirstChunk = true;

          await this.agent.chat(input, (text) => {
            if (isFirstChunk) {
              // 清除 "思考中..." 并显示 AI 前缀
              process.stdout.write('\r' + ' '.repeat(20) + '\r');
              process.stdout.write(chalk.blue('AI > '));
              isFirstChunk = false;
            }

            // 处理工具调用的输出
            if (text.startsWith('\n[调用工具:')) {
              process.stdout.write(chalk.yellow(text));
            } else if (text.startsWith('[结果:') || text.startsWith('[错误:')) {
              process.stdout.write(chalk.gray(text));
            } else {
              process.stdout.write(text);
            }
          });

          console.log('\n');
        } catch (error) {
          // 清除 "思考中..."
          process.stdout.write('\r' + ' '.repeat(20) + '\r');
          console.log(
            chalk.red(
              `❌ 错误: ${error instanceof Error ? error.message : String(error)}\n`
            )
          );
        }
      } catch {
        // readline 关闭，退出循环
        break;
      }
    }

    console.log(chalk.cyan('\n👋 再见！\n'));
  }

  // 关闭
  close(): void {
    if (!this.isClosed) {
      this.isClosed = true;
      this.rl.close();
    }
  }
}