#!/usr/bin/env node

/**
 * Import Translations Script
 *
 * Imports translations from a JSON export file into the database
 * Used to deploy translations from dev to production
 *
 * Usage:
 *   node scripts/import-translations.js <input-file>
 *
 * Options:
 *   --dry-run    Preview import without making changes
 *   --force      Overwrite existing translations
 */

require('dotenv').config();
const mongoose = require('mongoose');
const fs = require('fs');

const Document = require('../src/models/Document.model');

// Parse arguments
const args = process.argv.slice(2);
const options = {
  dryRun: args.includes('--dry-run'),
  force: args.includes('--force'),
  inputFile: args.find(arg => !arg.startsWith('--'))
};

if (!options.inputFile) {
  console.error('❌ ERROR: Input file required');
  console.error('Usage: node scripts/import-translations.js <input-file> [--dry-run] [--force]');
  process.exit(1);
}

async function main() {
  console.log('═══════════════════════════════════════════════════════════');
  console.log('  IMPORT TRANSLATIONS');
  console.log('═══════════════════════════════════════════════════════════\n');

  if (options.dryRun) {
    console.log('🔍 DRY-RUN MODE - No changes will be made\n');
  }

  // Load import file
  console.log(`📁 Loading ${options.inputFile}...`);
  if (!fs.existsSync(options.inputFile)) {
    console.error(`❌ ERROR: File not found: ${options.inputFile}`);
    process.exit(1);
  }

  const importData = JSON.parse(fs.readFileSync(options.inputFile, 'utf8'));
  console.log(`✓ Loaded export from ${importData.exported_at}`);
  console.log(`✓ Source: ${importData.source_database}`);
  console.log(`✓ Documents: ${importData.documents.length}`);
  console.log(`✓ Translations: ${importData.total_translations}\n`);

  // Connect to MongoDB
  console.log('📡 Connecting to MongoDB...');
  await mongoose.connect(process.env.MONGODB_URI || 'mongodb://localhost:27017/tractatus_dev', {
    serverSelectionTimeoutMS: 5000
  });
  console.log(`✓ Connected to ${process.env.MONGODB_URI || 'mongodb://localhost:27017/tractatus_dev'}\n`);

  // Import each document
  const stats = {
    total: importData.documents.length,
    imported: 0,
    skipped: 0,
    failed: 0,
    errors: []
  };

  console.log('📚 Importing translations...\n');

  for (const docData of importData.documents) {
    try {
      // Find document by slug (more reliable than _id across environments)
      const doc = await Document.findBySlug(docData.slug);

      if (!doc) {
        console.log(`  ⚠ ${docData.slug}: Document not found, skipping`);
        stats.skipped++;
        continue;
      }

      // Check if translations already exist
      const hasExisting = doc.translations && Object.keys(doc.translations).length > 0;

      if (hasExisting && !options.force) {
        console.log(`  ⏭ ${docData.slug}: Already has translations (use --force to overwrite)`);
        stats.skipped++;
        continue;
      }

      if (options.dryRun) {
        const langCount = Object.keys(docData.translations).length;
        console.log(`  🔍 ${docData.slug}: Would import ${langCount} translation(s) ${hasExisting ? '(overwrite)' : '(new)'}`);
        stats.imported++;
        continue;
      }

      // Import translations
      await Document.update(doc._id.toString(), {
        translations: docData.translations
      });

      const langCount = Object.keys(docData.translations).length;
      console.log(`  ✓ ${docData.slug}: Imported ${langCount} translation(s)`);
      stats.imported++;

    } catch (error) {
      console.error(`  ✗ ${docData.slug}: ${error.message}`);
      stats.failed++;
      stats.errors.push({
        slug: docData.slug,
        error: error.message
      });
    }
  }

  // Summary
  console.log('\n═══════════════════════════════════════════════════════════');
  console.log('  IMPORT SUMMARY');
  console.log('═══════════════════════════════════════════════════════════\n');

  if (options.dryRun) {
    console.log('  Dry run complete - no changes were made\n');
  }

  console.log(`  Total documents: ${stats.total}`);
  console.log(`  Imported: ${stats.imported}`);
  console.log(`  Skipped: ${stats.skipped}`);
  console.log(`  Failed: ${stats.failed}\n`);

  if (stats.errors.length > 0) {
    console.log('  Errors:');
    stats.errors.forEach(err => {
      console.log(`    - ${err.slug}: ${err.error}`);
    });
    console.log('');
  }

  await mongoose.disconnect();
  console.log('✓ Database disconnected\n');

  process.exit(stats.failed > 0 ? 1 : 0);
}

// Run
main().catch(err => {
  console.error('\n❌ Fatal error:', err.message);
  console.error(err.stack);
  process.exit(1);
});