import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { getDatabase, saveDatabase } from './connection.js';

const __dirname = path.dirname(fileURLToPath(import.meta.url));

export function runMigrations(): void {
  const db = getDatabase();

  db.run(`
    CREATE TABLE IF NOT EXISTS _migrations (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      name TEXT NOT NULL UNIQUE,
      applied_at TEXT DEFAULT (datetime('now'))
    )
  `);

  const migrationsDir = path.join(__dirname, 'migrations');

  // In production (compiled), migrations may be alongside the compiled JS
  const altMigrationsDir = path.join(__dirname, '..', '..', '..', 'src', 'server', 'db', 'migrations');
  const dir = fs.existsSync(migrationsDir) ? migrationsDir : (fs.existsSync(altMigrationsDir) ? altMigrationsDir : null);

  if (!dir) {
    console.warn('No migrations directory found');
    return;
  }

  const files = fs.readdirSync(dir)
    .filter((f) => f.endsWith('.sql'))
    .sort();

  const appliedStmt = db.prepare('SELECT name FROM _migrations');
  const applied = new Set<string>();
  while (appliedStmt.step()) {
    applied.add(appliedStmt.getAsObject().name as string);
  }
  appliedStmt.free();

  for (const file of files) {
    if (applied.has(file)) continue;

    const sql = fs.readFileSync(path.join(dir, file), 'utf-8');
    db.run(sql);
    db.run('INSERT INTO _migrations (name) VALUES (?)', [file]);
    console.log(`Migration applied: ${file}`);
  }

  saveDatabase();
}