require('dotenv').config();
const fs = require('fs').promises;
const path = require('path');
const connectDB = require('../config/database');
const Travel = require('../models/travel');
const mongoose = require('mongoose');

/**
 * Migration: travel
 * Migrate Travel data từ travel.json
 * Created: 2025-12-13
 */
async function migrate() {
  try {
    // Kết nối database
    await connectDB();
    console.log('Starting migration: travel...');
    
    // Đọc file travel.json
    const travelJsonPath = path.join(__dirname, '../data/travel.json');
    console.log('Reading JSON file from:', travelJsonPath);
    
    const travelData = JSON.parse(await fs.readFile(travelJsonPath, 'utf8'));
    console.log('Travel data loaded successfully');
    console.log('Data structure keys:', Object.keys(travelData));
    
    // Thực hiện migration
    await migrateTravelData(travelData);
    
    console.log('Travel migration completed successfully!');
    
    await mongoose.disconnect();
    process.exit(0);
  } catch (error) {
    console.error('Migration error:', error);
    process.exit(1);
  }
}

/**
 * Custom migration logic cho travel data
 */
async function migrateTravelData(travelData) {
  try {
    console.log('Starting custom migration logic...');
    
    // 1. Kiểm tra dữ liệu cũ
    const existingTravel = await Travel.findOne({});
    if (existingTravel) {
      console.log(`Found existing travel document: ${existingTravel._id}`);
      console.log('Deleting existing travel data...');
      await Travel.deleteMany({});
      console.log('Cleared existing travel data');
    }
    
    // 2. Chuyển đổi locations thành blog content blocks
    const contentBlocks = [];
    
    // If travelData already has posts (blog format), use the first post
    if (Array.isArray(travelData.posts) && travelData.posts.length > 0) {
      const firstPost = travelData.posts[0];
      if (firstPost.content && Array.isArray(firstPost.content.blocks)) {
        contentBlocks.push(...firstPost.content.blocks);
      }
    } else {
      // Thêm general description (legacy format)
      if (travelData.general) {
        contentBlocks.push({
          type: 'paragraph',
          data: {
            text: travelData.general.description
          }
        });
        
        // Thêm additional info như conclusion
        if (travelData.general.additionalInfo) {
          contentBlocks.push({
            type: 'conclusion',
            data: {
              text: travelData.general.additionalInfo,
              callToAction: {
                text: '',
                link: ''
              }
            }
          });
        }
      }
      
      // Chuyển đổi từng location thành blog blocks
      if (travelData.locations && Array.isArray(travelData.locations)) {
        travelData.locations.forEach(location => {
          // Header cho location
          contentBlocks.push({
            type: 'header',
            data: {
              text: location.title,
              level: 2
            }
          });

          // Address information
          const addressItems = [];
          if (location.address) {
            if (location.address.name) {
              addressItems.push(`Name: ${location.address.name}`);
            }
            if (location.address.line2) {
              addressItems.push(location.address.line2);
            }
            if (location.address.street) {
              addressItems.push(`Street: ${location.address.street}`);
            }
            if (location.address.postalCode && location.address.city) {
              const country = location.address.country ? `, ${location.address.country}` : '';
              addressItems.push(`Location: ${location.address.postalCode} ${location.address.city}${country}`);
            }
            if (location.address.googleMapsUrl) {
              addressItems.push(`Google Maps: <a href="${location.address.googleMapsUrl}" target="_blank">View on Map</a>`);
            }
          }
          
          if (addressItems.length > 0) {
            contentBlocks.push({
              type: 'list',
              data: {
                style: 'unordered',
                items: addressItems
              }
            });
          }
          
          // Address note as conclusion
          if (location.address?.note) {
            contentBlocks.push({
              type: 'conclusion',
              data: {
                text: location.address.note,
                callToAction: {
                  text: '',
                  link: ''
                }
              }
            });
          }
          
          // Contact information
          const contactItems = [];
          if (location.contact) {
            if (location.contact.email) {
              contactItems.push(`Email: ${location.contact.email}`);
            }
            if (location.contact.phone) {
              contactItems.push(`Phone: ${location.contact.phone}`);
            }
          }
          
          if (contactItems.length > 0) {
            contentBlocks.push({
              type: 'paragraph',
              data: {
                text: 'Contact Information:'
              }
            });
            contentBlocks.push({
              type: 'list',
              data: {
                style: 'unordered',
                items: contactItems
              }
            });
          }
          
          // Schedule information
          const scheduleItems = [];
          if (location.schedule) {
            if (location.schedule.arrival) {
              scheduleItems.push(`Arrival: ${location.schedule.arrival}`);
            }
            if (location.schedule.departure) {
              scheduleItems.push(`Departure: ${location.schedule.departure}`);
            }
          }
          
          if (scheduleItems.length > 0) {
            contentBlocks.push({
              type: 'paragraph',
              data: {
                text: 'Schedule:'
              }
            });
            contentBlocks.push({
              type: 'list',
              data: {
                style: 'unordered',
                items: scheduleItems
              }
            });
          }
        });
      }
    }
    
    // 3. Tạo document mới cho travel
    const travelDocument = new Travel({
      hero: {
        title: travelData.hero?.title || 'Travel Information',
        backgroundImage: travelData.hero?.backgroundImage || ''
      },
      
      page: {
        title: travelData.page?.title || travelData.general?.title || 'Go and Grow Camp Travel Information',
        description: travelData.page?.description || travelData.general?.description || '',
        year: travelData.page?.year || travelData.pageYear || undefined,
        metadata: {
          title: 'Travel Guide - Go and Grow Camp',
          description: 'Everything you need to know about traveling to our camps'
        }
      },
      
      content: {
        blocks: contentBlocks
      },
      
      enableScrollspy: true,
      lastUpdated: new Date()
    });
    
    // 4. Lưu vào database
    await travelDocument.save();
    console.log('Travel document saved successfully');
    
    // 5. Log thông tin
    console.log(`Created travel document with ID: ${travelDocument._id}`);
    console.log(`Hero title: ${travelDocument.hero.title}`);
    console.log(`Page title: ${travelDocument.page.title}`);
    console.log(`Content blocks count: ${travelDocument.content.blocks.length}`);
    console.log(`Converted ${travelData.locations?.length || 0} locations to blog blocks`);
    
  } catch (error) {
    console.error('Error in migrateTravelData:', error);
    throw error;
  }
}

/**
 * Hàm backup data trước khi migration
 */
async function backupExistingData() {
  try {
    console.log('Creating backup of existing travel data...');
    const existingTravel = await Travel.find({});
    
    if (existingTravel.length > 0) {
      const backupPath = path.join(__dirname, '../backups/travel-backup-' + Date.now() + '.json');
      
      // Tạo thư mục backup nếu chưa có
      await fs.mkdir(path.dirname(backupPath), { recursive: true });
      
      await fs.writeFile(backupPath, JSON.stringify(existingTravel, null, 2));
      console.log(`Backup created at: ${backupPath}`);
    }
  } catch (error) {
    console.error('Backup error:', error);
  }
}

// Chạy migration nếu được gọi trực tiếp
if (require.main === module) {
  migrate();
}

module.exports = { migrate, migrateTravelData };