const express = require('express');
const sqlite3 = require('sqlite3').verbose();
const path = require('path');

const app = express();
const PORT = 3000;

// 中间件
app.use(express.json());
app.use(express.static('public'));

// 数据库连接
const db = new sqlite3.Database('./tasks.db', (err) => {
  if (err) {
    console.error('❌ 数据库连接失败:', err.message);
    process.exit(1);
  }
  console.log('✅ 已连接到 SQLite 数据库');
});

// 初始化数据库表
db.serialize(() => {
  // 项目表
  db.run(`CREATE TABLE IF NOT EXISTS projects (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL,
    description TEXT,
    status TEXT DEFAULT 'active',
    created_by TEXT DEFAULT 'human',
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
  )`);
  
  // 任务表
  db.run(`CREATE TABLE IF NOT EXISTS tasks (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    project_id INTEGER NOT NULL,
    parent_id INTEGER,
    title TEXT NOT NULL,
    description TEXT,
    type TEXT DEFAULT 'development',
    priority TEXT DEFAULT 'normal',
    status TEXT DEFAULT 'initial',
    assigned_to TEXT,
    created_by TEXT DEFAULT 'human',
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (project_id) REFERENCES projects(id),
    FOREIGN KEY (parent_id) REFERENCES tasks(id)
  )`);
  
  // 智能体表
  db.run(`CREATE TABLE IF NOT EXISTS agents (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT UNIQUE NOT NULL,
    type TEXT,
    capabilities TEXT,
    status TEXT DEFAULT 'idle',
    current_task TEXT,
    completed_tasks INTEGER DEFAULT 0,
    last_heartbeat DATETIME DEFAULT CURRENT_TIMESTAMP
  )`);
  
  // 附件表
  db.run(`CREATE TABLE IF NOT EXISTS attachments (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    task_id INTEGER NOT NULL,
    filename TEXT NOT NULL,
    filepath TEXT NOT NULL,
    size INTEGER,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (task_id) REFERENCES tasks(id)
  )`);
  
  // 规约表 (支持全局和项目级别)
  db.run(`CREATE TABLE IF NOT EXISTS rules (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    project_id INTEGER,
    rule_no TEXT NOT NULL,
    rule_type TEXT NOT NULL,
    description TEXT NOT NULL,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (project_id) REFERENCES projects(id)
  )`);
  
  console.log('✅ 数据库表已初始化');
});

// ==================== API 路由 ====================

// 健康检查
app.get('/health', (req, res) => {
  res.json({ 
    status: 'ok',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
    memory: process.memoryUsage(),
    version: require('./package.json').version
  });
});

// 统计信息
app.get('/api/stats', (req, res) => {
  const stats = {};
  
  db.get('SELECT COUNT(*) as count FROM projects', (err, row) => {
    stats.projects = row ? row.count : 0;
    
    db.get('SELECT COUNT(*) as count FROM tasks', (err, row) => {
      stats.tasks = row ? row.count : 0;
      
      db.get('SELECT COUNT(*) as count FROM tasks WHERE status = "in_progress"', (err, row) => {
        stats.in_progress_tasks = row ? row.count : 0;
        
        db.get('SELECT COUNT(*) as count FROM tasks WHERE status = "completed"', (err, row) => {
          stats.completed_tasks = row ? row.count : 0;
          
          db.get('SELECT COUNT(*) as count FROM agents', (err, row) => {
            stats.total_agents = row ? row.count : 0;
            
            db.get('SELECT COUNT(*) as count FROM agents WHERE status = "busy"', (err, row) => {
              stats.active_agents = row ? row.count : 0;
              res.json(stats);
            });
          });
        });
      });
    });
  });
});

// 项目管理
app.get('/api/projects', (req, res) => {
  db.all('SELECT * FROM projects ORDER BY created_at DESC', (err, rows) => {
    if (err) return res.status(500).json({ error: err.message });
    res.json(rows || []);
  });
});

app.post('/api/projects', (req, res) => {
  const { name, description, created_by = 'human' } = req.body;
  
  db.run(
    'INSERT INTO projects (name, description, created_by) VALUES (?, ?, ?)',
    [name, description, created_by],
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      res.json({ id: this.lastID, name, description, created_by });
    }
  );
});

app.get('/api/projects/:id', (req, res) => {
  db.get('SELECT * FROM projects WHERE id = ?', [req.params.id], (err, row) => {
    if (err) return res.status(500).json({ error: err.message });
    if (!row) return res.status(404).json({ error: 'Project not found' });
    res.json(row);
  });
});

app.delete('/api/projects/:id', (req, res) => {
  // 先删除项目下的所有任务
  db.run('DELETE FROM tasks WHERE project_id = ?', [req.params.id], (err) => {
    if (err) return res.status(500).json({ error: err.message });
    
    // 然后删除项目
    db.run('DELETE FROM projects WHERE id = ?', [req.params.id], function(err) {
      if (err) return res.status(500).json({ error: err.message });
      if (this.changes === 0) return res.status(404).json({ error: 'Project not found' });
      res.json({ success: true });
    });
  });
});

// 任务管理
app.get('/api/tasks', (req, res) => {
  const { project_id } = req.query;
  let query = 'SELECT t.*, (SELECT COUNT(*) FROM tasks WHERE parent_id = t.id) as subtask_count, (SELECT COUNT(*) FROM attachments WHERE task_id = t.id) as attachment_count FROM tasks t';
  let params = [];
  
  if (project_id) {
    query += ' WHERE t.project_id = ?';
    params.push(project_id);
  }
  
  query += ' ORDER BY t.created_at DESC';
  
  db.all(query, params, (err, rows) => {
    if (err) return res.status(500).json({ error: err.message });
    res.json(rows || []);
  });
});

app.post('/api/tasks', (req, res) => {
  const { project_id, parent_id, title, description, type = 'development', priority = 'normal', status = 'initial', assigned_to, created_by = 'human' } = req.body;
  
  db.run(
    'INSERT INTO tasks (project_id, parent_id, title, description, type, priority, status, assigned_to, created_by) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)',
    [project_id, parent_id || null, title, description, type, priority, status, assigned_to || null, created_by],
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      res.json({ id: this.lastID, project_id, title, type, priority, status });
    }
  );
});

app.get('/api/tasks/:id', (req, res) => {
  db.get('SELECT * FROM tasks WHERE id = ?', [req.params.id], (err, task) => {
    if (err) return res.status(500).json({ error: err.message });
    if (!task) return res.status(404).json({ error: 'Task not found' });
    
    // 获取附件
    db.all('SELECT * FROM attachments WHERE task_id = ?', [req.params.id], (err, attachments) => {
      task.attachments = attachments || [];
      
      // 获取子任务
      db.all('SELECT * FROM tasks WHERE parent_id = ?', [req.params.id], (err, subtasks) => {
        task.subtasks = subtasks || [];
        res.json(task);
      });
    });
  });
});

app.put('/api/tasks/:id', (req, res) => {
  const updates = [];
  const values = [];
  
  ['status', 'type', 'priority', 'assigned_to', 'title', 'description'].forEach(field => {
    if (req.body[field] !== undefined) {
      updates.push(`${field} = ?`);
      values.push(req.body[field]);
    }
  });
  
  if (updates.length === 0) {
    return res.status(400).json({ error: 'No fields to update' });
  }
  
  values.push(req.params.id);
  
  db.run(
    `UPDATE tasks SET ${updates.join(', ')} WHERE id = ?`,
    values,
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      if (this.changes === 0) return res.status(404).json({ error: 'Task not found' });
      res.json({ success: true });
    }
  );
});

app.delete('/api/tasks/:id', (req, res) => {
  db.run('DELETE FROM tasks WHERE id = ?', [req.params.id], function(err) {
    if (err) return res.status(500).json({ error: err.message });
    res.json({ success: true });
  });
});

// 智能体管理
app.get('/api/agents', (req, res) => {
  db.all('SELECT * FROM agents ORDER BY name', (err, rows) => {
    if (err) return res.status(500).json({ error: err.message });
    res.json(rows || []);
  });
});

app.post('/api/agents', (req, res) => {
  const { name, type, capabilities } = req.body;
  
  db.run(
    'INSERT INTO agents (name, type, capabilities) VALUES (?, ?, ?)',
    [name, type, JSON.stringify(capabilities)],
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      res.json({ id: this.lastID, name, type, capabilities });
    }
  );
});

// 规约管理 (支持多条目)
// 获取全局规约列表
app.get('/api/rules/global', (req, res) => {
  db.all('SELECT * FROM rules WHERE project_id IS NULL ORDER BY rule_no', (err, rows) => {
    if (err) return res.status(500).json({ error: err.message });
    res.json(rows || []);
  });
});

// 获取项目规约列表
app.get('/api/rules/project/:projectId', (req, res) => {
  db.all('SELECT * FROM rules WHERE project_id = ? ORDER BY rule_no', [req.params.projectId], (err, rows) => {
    if (err) return res.status(500).json({ error: err.message });
    res.json(rows || []);
  });
});

// 获取单个规约
app.get('/api/rules/:id', (req, res) => {
  db.get('SELECT * FROM rules WHERE id = ?', [req.params.id], (err, row) => {
    if (err) return res.status(500).json({ error: err.message });
    if (!row) return res.status(404).json({ error: 'Rule not found' });
    res.json(row);
  });
});

// 创建规约
app.post('/api/rules', (req, res) => {
  const { project_id, rule_no, rule_type, description } = req.body;
  
  db.run(
    'INSERT INTO rules (project_id, rule_no, rule_type, description) VALUES (?, ?, ?, ?)',
    [project_id || null, rule_no, rule_type, description],
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      res.json({ id: this.lastID, project_id, rule_no, rule_type, description });
    }
  );
});

// 更新规约
app.put('/api/rules/:id', (req, res) => {
  const { rule_no, rule_type, description } = req.body;
  const updates = [];
  const values = [];
  
  if (rule_no !== undefined) { updates.push('rule_no = ?'); values.push(rule_no); }
  if (rule_type !== undefined) { updates.push('rule_type = ?'); values.push(rule_type); }
  if (description !== undefined) { updates.push('description = ?'); values.push(description); }
  updates.push('updated_at = CURRENT_TIMESTAMP');
  
  if (values.length === 0) {
    return res.status(400).json({ error: 'No fields to update' });
  }
  
  values.push(req.params.id);
  
  db.run(
    `UPDATE rules SET ${updates.join(', ')} WHERE id = ?`,
    values,
    function(err) {
      if (err) return res.status(500).json({ error: err.message });
      res.json({ success: true });
    }
  );
});

// 删除规约
app.delete('/api/rules/:id', (req, res) => {
  db.run('DELETE FROM rules WHERE id = ?', [req.params.id], function(err) {
    if (err) return res.status(500).json({ error: err.message });
    res.json({ success: true });
  });
});


// 错误处理中间件（必须在所有路由之后）
app.use((err, req, res, next) => {
  console.error('❌ API错误:', err.stack);
  res.status(500).json({ 
    error: err.message || '服务器内部错误',
    timestamp: new Date().toISOString()
  });
});

// 启动服务器
const server = app.listen(PORT, () => {
  console.log(`🚀 多智能体任务管理系统已启动`);
  console.log(`   本地访问: http://localhost:${PORT}`);
  console.log(`   远程访问: http://10.0.6.5:${PORT}`);
});

// 监听端口错误
server.on('error', (err) => {
  if (err.code === 'EADDRINUSE') {
    console.error(`❌ 端口 ${PORT} 已被占用`);
    console.error(`   请先停止占用端口的进程: lsof -ti:${PORT} | xargs kill -9`);
    process.exit(1);
  } else {
    console.error('❌ 服务器启动失败:', err);
    process.exit(1);
  }
});

// 全局异常捕获
process.on('uncaughtException', (err) => {
  console.error('❌ 未捕获异常:', err);
  console.error('   堆栈:', err.stack);
  // 不退出进程，继续运行
});

process.on('unhandledRejection', (reason, promise) => {
  console.error('❌ 未处理的Promise拒绝:', reason);
  console.error('   Promise:', promise);
  // 不退出进程，继续运行
});

// 优雅关闭
process.on('SIGINT', () => {
  console.log('\n⏸️  收到关闭信号，准备关闭服务器...');
  server.close(() => {
    console.log('📡 HTTP服务器已关闭');
    db.close((err) => {
      if (err) {
        console.error('❌ 数据库关闭失败:', err);
        process.exit(1);
      }
      console.log('💾 数据库连接已关闭');
      console.log('👋 服务器已完全关闭');
      process.exit(0);
    });
  });
  
  // 强制超时退出（10秒）
  setTimeout(() => {
    console.error('⚠️  强制退出（超时）');
    process.exit(1);
  }, 10000);
});