import fs from 'fs';
import path from 'path';
import sqlite3 from 'sqlite3';
import { open, Database } from 'sqlite';
import { config } from './config';

let db: Database<sqlite3.Database, sqlite3.Statement> | null = null;

export async function getDb(): Promise<Database<sqlite3.Database, sqlite3.Statement>> {
  if (db) return db;

  const dbDir = path.dirname(config.dbPath);
  if (!fs.existsSync(dbDir)) {
    fs.mkdirSync(dbDir, { recursive: true });
  }

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

  await initSchema();
  return db;
}

async function initSchema(): Promise<void> {
  const database = await getDb();

  await database.exec(`
    CREATE TABLE IF NOT EXISTS users (
      id TEXT PRIMARY KEY,
      username TEXT UNIQUE NOT NULL,
      password_hash TEXT NOT NULL,
      role TEXT NOT NULL DEFAULT 'admin',
      created_at TEXT NOT NULL
    );

    CREATE TABLE IF NOT EXISTS accounts (
      id TEXT PRIMARY KEY,
      name TEXT NOT NULL,
      access_key_id TEXT NOT NULL,
      access_key_secret TEXT NOT NULL,
      region TEXT NOT NULL,
      endpoint TEXT,
      is_active INTEGER NOT NULL DEFAULT 0,
      created_at TEXT NOT NULL,
      updated_at TEXT NOT NULL
    );

    CREATE INDEX IF NOT EXISTS idx_accounts_active ON accounts(is_active);

    CREATE TABLE IF NOT EXISTS operation_logs (
      id TEXT PRIMARY KEY,
      user_id TEXT,
      username TEXT,
      action TEXT NOT NULL,
      target_type TEXT NOT NULL,
      target_ids TEXT,
      details TEXT,
      created_at TEXT NOT NULL
    );

    CREATE INDEX IF NOT EXISTS idx_logs_created ON operation_logs(created_at);
    CREATE INDEX IF NOT EXISTS idx_logs_action ON operation_logs(action);
  `);
}