const fs = require('fs');
const path = require('path');
const { query, closePool, dbReady } = require('./db');

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

async function runMigrations() {
  try {
    // Wait for schema to be initialized before running migrations
    await dbReady;

    // Create migrations tracking table if it doesn't exist
    await query(`
            CREATE TABLE IF NOT EXISTS schema_migrations (
                id SERIAL PRIMARY KEY,
                filename VARCHAR(255) NOT NULL UNIQUE,
                applied_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
            )
        `);

    // Get list of already applied migrations
    const applied = await query('SELECT filename FROM schema_migrations ORDER BY filename');
    const appliedSet = new Set(applied.rows.map((r) => r.filename));

    // Read all .sql files from migrations directory, sorted alphabetically
    const files = fs
      .readdirSync(MIGRATIONS_DIR)
      .filter((f) => f.endsWith('.sql'))
      .sort();

    let migrationsRun = 0;

    for (const file of files) {
      if (appliedSet.has(file)) {
        continue;
      }
      const filePath = path.join(MIGRATIONS_DIR, file);
      const sql = fs.readFileSync(filePath, 'utf8');

      // Execute the entire migration as a single statement block
      await query(sql);

      // Record the migration
      await query('INSERT INTO schema_migrations (filename) VALUES ($1)', [file]);
      migrationsRun++;
    }

    if (migrationsRun === 0) {
    } else {
    }
  } catch (error) {
    console.error('Migration error:', error.message);
    throw error;
  }
}

// Run if executed directly
if (require.main === module) {
  runMigrations()
    .then(() => closePool())
    .then(() => process.exit(0))
    .catch(() => {
      closePool().then(() => process.exit(1));
    });
}

module.exports = { runMigrations };