const sqlite3 = require('sqlite3').verbose();
const { DB_PATH } = require('./config');
const fs = require('fs');
const path = require('path');

// Ensure the directory exists with proper permissions
const dbDir = path.dirname(DB_PATH);
if (!fs.existsSync(dbDir)) {
  try {
    fs.mkdirSync(dbDir, { recursive: true });
    console.log('Created database directory:', dbDir);
  } catch (err) {
    console.error('Failed to create database directory:', err.message);
  }
}

// Try to create the database file if it doesn't exist
try {
  fs.closeSync(fs.openSync(DB_PATH, 'a'));
  console.log('Database file is accessible:', DB_PATH);
} catch (err) {
  console.error('Failed to access database file:', err.message);
}

const db = new sqlite3.Database(DB_PATH, (err) => {
  if (err) {
    console.error('数据库连接失败:', err.message);
    console.error('数据库路径:', DB_PATH);
    console.error('当前工作目录:', process.cwd());
    process.exit(1);
  }
  console.log('已连接到 SQLite 数据库');
});

function initializeDatabase() {
  db.serialize(() => {
    db.run(`CREATE TABLE IF NOT EXISTS users (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      username TEXT UNIQUE NOT NULL,
      password_hash TEXT NOT NULL,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    )`);

    db.run(`CREATE TABLE IF NOT EXISTS calendar_marks (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      user_id INTEGER NOT NULL,
      date TEXT NOT NULL,
      status TEXT NOT NULL,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
      updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
      UNIQUE(user_id, date),
      FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
    )`);

    db.run(`CREATE INDEX IF NOT EXISTS idx_user_date ON calendar_marks(user_id, date)`);
  });
}

initializeDatabase();

function closeDatabase() {
  return new Promise((resolve) => {
    db.close((err) => {
      if (err) {
        console.error('关闭数据库失败:', err.message);
      } else {
        console.log('数据库连接已关闭');
      }
      resolve();
    });
  });
}

module.exports = {
  db,
  closeDatabase
};