/**
 * Delete all or specific Context records from database
 * WARNING: This will permanently delete data!
 */

const { sequelize } = require('./config/database');
const { Context } = require('./models');

// ============================================
// CONFIGURATION
// ============================================

const DELETE_MODE = 'all'; // Options: 'all', 'vocabulary_only', 'by_type'

// For 'by_type' mode - specify which type to delete
const TYPE_TO_DELETE = 'vocabulary'; // e.g., 'vocabulary', 'grammar', etc.

// For safety confirmation
const CONFIRM_DELETE = true; // Set to true to actually delete

// ============================================
// MAIN FUNCTIONS
// ============================================

async function deleteAllContext() {
  console.log('🗑️  Deleting ALL context records...');
  
  const count = await Context.count();
  console.log(`📊 Found ${count} records to delete`);
  
  if (!CONFIRM_DELETE) {
    console.log('⚠️  CONFIRM_DELETE is false. Set it to true to proceed.');
    return 0;
  }

  const result = await Context.destroy({
    where: {},
    truncate: true
  });

  console.log(`✅ Deleted all context records`);
  return count;
}

async function deleteVocabularyOnly() {
  console.log('🗑️  Deleting vocabulary context records only...');
  
  const count = await Context.count({
    where: { type: 'vocabulary' }
  });
  console.log(`📊 Found ${count} vocabulary records to delete`);
  
  if (!CONFIRM_DELETE) {
    console.log('⚠️  CONFIRM_DELETE is false. Set it to true to proceed.');
    return 0;
  }

  const result = await Context.destroy({
    where: { type: 'vocabulary' }
  });

  console.log(`✅ Deleted ${result} vocabulary records`);
  return result;
}

async function deleteByType(type) {
  console.log(`🗑️  Deleting context records with type: ${type}...`);
  
  const count = await Context.count({
    where: { type: type }
  });
  console.log(`📊 Found ${count} records to delete`);
  
  if (!CONFIRM_DELETE) {
    console.log('⚠️  CONFIRM_DELETE is false. Set it to true to proceed.');
    return 0;
  }

  const result = await Context.destroy({
    where: { type: type }
  });

  console.log(`✅ Deleted ${result} records with type '${type}'`);
  return result;
}

async function showStats() {
  console.log('\n📊 Current Context Statistics:');
  
  const total = await Context.count();
  console.log(`Total records: ${total}`);
  
  // Count by type
  const types = await sequelize.query(
    'SELECT type, COUNT(*) as count FROM context GROUP BY type',
    { type: sequelize.QueryTypes.SELECT }
  );
  
  console.log('\nBy Type:');
  types.forEach(t => {
    console.log(`  - ${t.type}: ${t.count}`);
  });
  
  return total;
}

// ============================================
// MAIN EXECUTION
// ============================================

async function main() {
  try {
    console.log('🔄 Starting Context deletion script...\n');
    
    await sequelize.authenticate();
    console.log('✅ Database connection OK\n');

    // Show current stats
    await showStats();
    console.log('\n---\n');

    let result = 0;

    switch (DELETE_MODE) {
      case 'all':
        result = await deleteAllContext();
        break;
      
      case 'vocabulary_only':
        result = await deleteVocabularyOnly();
        break;
      
      case 'by_type':
        result = await deleteByType(TYPE_TO_DELETE);
        break;
      
      default:
        console.log('❌ Invalid DELETE_MODE');
    }

    console.log('\n---\n');
    
    // Show stats after deletion
    await showStats();

    console.log('\n✅ Operation complete!');
    console.log(`📊 Records deleted: ${result}`);
    
    process.exit(0);
  } catch (error) {
    console.error('❌ Error during deletion:', error.message);
    console.error(error.stack);
    process.exit(1);
  }
}

// Safety check
if (!CONFIRM_DELETE) {
  console.log('\n⚠️  WARNING: CONFIRM_DELETE is set to false');
  console.log('This is a DRY RUN. No data will be deleted.');
  console.log('Set CONFIRM_DELETE = true to actually delete data.\n');
}

// Run the script
main();