/**
 * Destination Controller - Full CRUD for Tourism Spots (PostgreSQL)
 */
const { getPool } = require('../db');
const { eventBus, EVENTS } = require('../services/eventBus');

/**
 * List all destinations
 */
async function list(req, res) {
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  try {
    const { category, district, limit = 50, offset = 0 } = req.query;
    let query = 'SELECT * FROM destinations WHERE 1=1';
    const params = [];
    let paramCounter = 1;
    
    if (category) {
      query += ` AND category = $${paramCounter++}`;
      params.push(category);
    }
    if (district) {
      query += ` AND district = $${paramCounter++}`;
      params.push(district);
    }
    
    query += ` ORDER BY created_at DESC LIMIT $${paramCounter++} OFFSET $${paramCounter++}`;
    params.push(parseInt(limit), parseInt(offset));
    
    const result = await pool.query(query, params);
    res.json({ success: true, count: result.rows.length, data: result.rows });
  } catch (error) {
    console.error('[Dest List Error]', error.message);
    res.status(500).json({ error: 'Failed to fetch destinations' });
  }
}

/**
 * Create destination
 */
async function create(req, res) {
  const data = req.body;
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  try {
    const slug = data.name.toLowerCase().replace(/ /g, '-').replace(/[^\w-]+/g, '');
    
    const query = `
      INSERT INTO destinations (name, slug, description, category, district, latitude, longitude, highlights, media)
      VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)
      RETURNING id, name, slug
    `;
    
    const params = [
      data.name,
      slug,
      data.description,
      data.category,
      data.district || 'Jhargram',
      data.latitude,
      data.longitude,
      JSON.stringify(data.highlights || []),
      JSON.stringify(data.media || [])
    ];
    
    const result = await pool.query(query, params);
    const destination = result.rows[0];
    
    // Emit event for Yatra-X re-indexing
    eventBus.emit(EVENTS.DESTINATION_CREATED, { id: destination.id, slug: destination.slug });
    
    res.status(201).json({ success: true, data: destination });
  } catch (error) {
    console.error('[Dest Create Error]', error.message);
    res.status(500).json({ error: 'Failed to create destination' });
  }
}

/**
 * Update destination
 */
async function update(req, res) {
  const { id } = req.params;
  const data = req.body;
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  try {
    const updates = [];
    const params = [id];
    let paramCounter = 2;
    
    const allowedFields = ['name', 'description', 'category', 'district', 'latitude', 'longitude', 'highlights', 'media', 'is_active'];
    
    allowedFields.forEach(field => {
      if (data[field] !== undefined) {
        updates.push(`${field} = $${paramCounter++}`);
        params.push(typeof data[field] === 'object' ? JSON.stringify(data[field]) : data[field]);
      }
    });
    
    if (updates.length === 0) return res.status(400).json({ error: 'No fields to update' });
    
    updates.push('updated_at = NOW()');
    
    const query = `UPDATE destinations SET ${updates.join(', ')} WHERE id = $1`;
    await pool.query(query, params);
    
    // Emit event for Yatra-X re-indexing
    eventBus.emit(EVENTS.DESTINATION_UPDATED, { id });
    
    res.json({ success: true, message: 'Destination updated' });
  } catch (error) {
    console.error('[Dest Update Error]', error.message);
    res.status(500).json({ error: 'Failed to update destination' });
  }
}

/**
 * Delete destination
 */
async function remove(req, res) {
  const { id } = req.params;
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  try {
    await pool.query('DELETE FROM destinations WHERE id = $1', [id]);
    
    // Emit event for Yatra-X re-indexing
    eventBus.emit(EVENTS.DESTINATION_DELETED, { id });
    
    res.json({ success: true, message: 'Destination deleted' });
  } catch (error) {
    console.error('[Dest Delete Error]', error.message);
    res.status(500).json({ error: 'Failed to delete destination' });
  }
}

module.exports = { list, create, update, remove };