import sqlite3 from 'sqlite3';
import { open, Database } from 'sqlite';

let db: Database | null = null;

export async function getDb() {
  if (db) return db;

  // Enable verbose mode for debugging
  sqlite3.verbose();

  const dbPath = process.env.DB_PATH || './dashboard.db';

  db = await open({
    filename: dbPath,
    driver: sqlite3.Database
  });

  await db.exec(`
    CREATE TABLE IF NOT EXISTS uptime_logs (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      service_name TEXT NOT NULL,
      url TEXT NOT NULL,
      status TEXT NOT NULL,
      latency INTEGER,
      timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
    );

    CREATE TABLE IF NOT EXISTS visitors (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      ip_hash TEXT,
      city TEXT,
      country TEXT,
      lat REAL,
      lon REAL,
      timestamp DATETIME DEFAULT CURRENT_TIMESTAMP
    );

    CREATE TABLE IF NOT EXISTS monitored_services (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT NOT NULL UNIQUE,
      url TEXT NOT NULL,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    );

    CREATE INDEX IF NOT EXISTS idx_uptime_logs_service_timestamp
      ON uptime_logs(service_name, timestamp);

    CREATE TABLE IF NOT EXISTS rss_feeds (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT NOT NULL,
      url TEXT NOT NULL UNIQUE,
      last_fetched DATETIME,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    );

    CREATE TABLE IF NOT EXISTS rss_items (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      feed_id INTEGER NOT NULL,
      title TEXT NOT NULL,
      link TEXT NOT NULL UNIQUE,
      pub_date DATETIME,
      creator TEXT,
      snippet TEXT,
      read INTEGER DEFAULT 0,
      bookmarked INTEGER DEFAULT 0,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    );

    CREATE INDEX IF NOT EXISTS idx_rss_items_feed ON rss_items(feed_id);
    CREATE INDEX IF NOT EXISTS idx_rss_items_pubdate ON rss_items(pub_date DESC);
  `);

  // Seed default HN feed if rss_feeds is empty
  const feedCount = await db.get('SELECT COUNT(*) as cnt FROM rss_feeds');
  if (feedCount?.cnt === 0) {
    await db.run(
      'INSERT INTO rss_feeds (name, url) VALUES (?, ?)',
      'Hacker News', 'https://news.ycombinator.com/rss'
    );
  }

  return db;
}