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

async function runMigrations() {
  try {
    await query(`
            CREATE TABLE IF NOT EXISTS schema_migrations (
                id SERIAL PRIMARY KEY,
                filename VARCHAR(255) UNIQUE NOT NULL,
                applied_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            )
        `);
    await query(`
            CREATE INDEX IF NOT EXISTS idx_schema_migrations_filename
            ON schema_migrations(filename)
        `);

    // Get all migration files
    const migrationsDir = path.join(__dirname, 'migrations');

    if (!fs.existsSync(migrationsDir)) {
      return;
    }

    const files = fs
      .readdirSync(migrationsDir)
      .filter((f) => f.endsWith('.sql'))
      .sort(); // Run in alphabetical order (001_, 002_, etc.)

    if (files.length === 0) {
      return;
    }

    let appliedCount = 0;
    let skippedCount = 0;

    // Process each migration file
    for (const file of files) {
      // Check if migration has already been applied
      const checkResult = await query('SELECT * FROM schema_migrations WHERE filename = $1', [
        file,
      ]);

      if (checkResult.rows.length > 0) {
        skippedCount++;
        continue;
      }

      // Apply new migration
      try {
        const filePath = path.join(migrationsDir, file);
        const sql = fs.readFileSync(filePath, 'utf8');

        // Execute migration SQL
        await query(sql);

        // Record migration as applied
        await query('INSERT INTO schema_migrations (filename) VALUES ($1)', [file]);
        appliedCount++;
      } catch (error) {
        console.error(`  ❌ ${file} - FAILED`);
        console.error(`     Error: ${error.message}`);
        throw error; // Stop on first error
      }
    }
  } catch (error) {
    console.error('\n' + '='.repeat(50));
    console.error('❌ Migration failed!');
    console.error('='.repeat(50));
    console.error(error);
    console.error('\n⚠️  Server startup aborted due to migration failure\n');
    throw error; // Re-throw to prevent server from starting
  }
}

module.exports = { runMigrations };