/**
 * Hotel Search and Booking Tools
 * Implements searchHotels and bookHotel MCP tools
 */

import { getHotelsByCity, getHotelById, generateHotelPrice } from '../data/hotels.js';
import { generatePNR } from '../data/pnr.js';
import { storage } from '../session/storage.js';
import { logger } from '../utils/logger.js';
import { ValidationError, BookingError } from '../utils/errors.js';
import {
  validateRequired,
  validateString,
  validateNumber,
  validateFutureDate
} from '../validation/validators.js';

/**
 * Search for available hotels
 * @param {Object} params - Search parameters
 * @param {string} sessionId - Session identifier
 * @returns {Promise<Object>} Search results
 */
export async function searchHotels(params: any, sessionId: any) {
  try {
    // Validate required fields
    validateRequired(params.cityCode, 'cityCode');
    validateRequired(params.checkInDate, 'checkInDate');
    validateRequired(params.checkOutDate, 'checkOutDate');
    
    validateString(params.cityCode, 'cityCode', { minLength: 3, maxLength: 3 });
    validateFutureDate(params.checkInDate, 'checkInDate');
    validateFutureDate(params.checkOutDate, 'checkOutDate');
    
    if (params.guests) {
      validateNumber(params.guests, 'guests', { min: 1, max: 10 });
    }

    const cityCode = params.cityCode.toUpperCase();
    const checkInDate = new Date(params.checkInDate);
    const checkOutDate = new Date(params.checkOutDate);
    const guests = params.guests || 1;

    // Validate date range
    if (checkOutDate <= checkInDate) {
      throw new ValidationError('checkOutDate must be after checkInDate');
    }

    const checkInDateObj = new Date(checkInDate);
    const checkOutDateObj = new Date(checkOutDate);
    const nights = Math.ceil((checkOutDateObj.getTime() - checkInDateObj.getTime()) / (1000 * 60 * 60 * 24));
    
    if (nights < 1) {
      throw new ValidationError('Minimum stay is 1 night');
    }

    // Get hotels for city
    const cityHotels = getHotelsByCity(cityCode);
    
    if (cityHotels.length === 0) {
      return {
        cityCode,
        checkInDate: params.checkInDate,
        checkOutDate: params.checkOutDate,
        nights,
        results: [],
        message: `No hotels found for city code ${cityCode}`
      };
    }

    // Select 5-10 hotels and generate pricing
    const numResults = Math.min(cityHotels.length, Math.floor(Math.random() * 6) + 5);
    const selectedHotels = cityHotels
      .sort(() => Math.random() - 0.5)
      .slice(0, numResults);

    const results = selectedHotels.map(hotel => {
      const pricing = generateHotelPrice(hotel.basePrice, nights, params.checkInDate);
      
      return {
        hotelId: hotel.id,
        name: hotel.name,
        chain: hotel.chain,
        stars: hotel.stars,
        address: hotel.address,
        amenities: hotel.amenities,
        pricing: {
          pricePerNight: pricing.pricePerNight,
          nights: pricing.nights,
          totalPrice: pricing.totalPrice,
          currency: 'USD'
        },
        availability: 'available' // Mock: always available
      };
    });

    logger.info({ sessionId, cityCode, nights, resultCount: results.length }, 'Hotel search completed');

    return {
      cityCode,
      checkInDate: params.checkInDate,
      checkOutDate: params.checkOutDate,
      nights,
      guests,
      results
    };

  } catch (error) {
    logger.error({ error, sessionId }, 'Hotel search failed');
    throw error;
  }
}

/**
 * Book a hotel
 * @param {Object} params - Booking parameters
 * @param {string} sessionId - Session identifier
 * @returns {Promise<Object>} Booking confirmation
 */
export async function bookHotel(params: any, sessionId: any) {
  try {
    // Validate required fields
    validateRequired(params.hotelId, 'hotelId');
    validateRequired(params.checkInDate, 'checkInDate');
    validateRequired(params.checkOutDate, 'checkOutDate');
    validateRequired(params.guestName, 'guestName');
    validateRequired(params.guestEmail, 'guestEmail');
    
    const { hotelId, checkInDate, checkOutDate, guestName, guestEmail, guestPhone, pnr: existingPnr, roomType } = params;

    // Validate hotel exists
    const hotel = getHotelById(hotelId);
    if (!hotel) {
      throw new ValidationError(`Hotel not found: ${hotelId}`);
    }

    // Validate dates
    validateFutureDate(checkInDate, 'checkInDate');
    validateFutureDate(checkOutDate, 'checkOutDate');
    
    const checkIn = new Date(checkInDate);
    const checkOut = new Date(checkOutDate);
    
    if (checkOut <= checkIn) {
      throw new ValidationError('checkOutDate must be after checkInDate');
    }

    const checkInDateObj = new Date(params.checkInDate);
    const checkOutDateObj = new Date(params.checkOutDate);
    const nights = Math.ceil((checkOutDateObj.getTime() - checkInDateObj.getTime()) / (1000 * 60 * 60 * 24));
    
    // Calculate pricing
    const pricing = generateHotelPrice(hotel.basePrice, nights, checkInDate);

    // Generate or use existing PNR
    const pnr = existingPnr || generatePNR();
    const client = storage.client;

    // Check if this is adding to existing booking
    let booking;
    if (existingPnr) {
      const existingKey = `gds:session:${sessionId}:booking:${existingPnr}`;
      const existingData = await client.get(existingKey);
      
      if (!existingData) {
        throw new BookingError(`Booking not found: ${existingPnr}`);
      }
      
      booking = JSON.parse(existingData);
      
      // Add hotel segment
      if (!booking.hotels) {
        booking.hotels = [];
      }
      
      booking.hotels.push({
        hotelId: hotel.id,
        name: hotel.name,
        chain: hotel.chain,
        stars: hotel.stars,
        address: hotel.address,
        checkInDate,
        checkOutDate,
        nights,
        roomType: roomType || 'Standard',
        guestName,
        guestEmail,
        guestPhone,
        pricing: {
          pricePerNight: pricing.pricePerNight,
          nights: pricing.nights,
          totalPrice: pricing.totalPrice,
          currency: 'USD'
        },
        status: 'confirmed',
        bookedAt: new Date().toISOString()
      });

      // Recalculate total price
      let totalPrice = 0;
      if (booking.flights) {
        totalPrice += booking.flights.reduce((sum, f) => sum + (f.pricing?.totalPrice || 0), 0);
      }
      if (booking.hotels) {
        totalPrice += booking.hotels.reduce((sum, h) => sum + (h.pricing?.totalPrice || 0), 0);
      }
      if (booking.cars) {
        totalPrice += booking.cars.reduce((sum, c) => sum + (c.pricing?.totalPrice || 0), 0);
      }
      
      booking.totalPrice = totalPrice;
      booking.updatedAt = new Date().toISOString();
      
    } else {
      // Create new hotel-only booking
      booking = {
        pnr,
        type: 'hotel',
        status: 'confirmed',
        hotels: [{
          hotelId: hotel.id,
          name: hotel.name,
          chain: hotel.chain,
          stars: hotel.stars,
          address: hotel.address,
          checkInDate,
          checkOutDate,
          nights,
          roomType: roomType || 'Standard',
          guestName,
          guestEmail,
          guestPhone,
          pricing: {
            pricePerNight: pricing.pricePerNight,
            nights: pricing.nights,
            totalPrice: pricing.totalPrice,
            currency: 'USD'
          },
          status: 'confirmed',
          bookedAt: new Date().toISOString()
        }],
        totalPrice: pricing.totalPrice,
        currency: 'USD',
        createdAt: new Date().toISOString(),
        sessionId
      };
    }

    // Store booking
    const bookingKey = `gds:session:${sessionId}:booking:${pnr}`;
    await client.set(bookingKey, JSON.stringify(booking), 'EX', 3600);

    // Update session bookings set
    await client.sadd(`gds:session:${sessionId}:bookings`, pnr);

    logger.info({ sessionId, pnr, hotelId, nights }, 'Hotel booking created');

    return {
      pnr,
      status: 'confirmed',
      hotel: {
        hotelId: hotel.id,
        name: hotel.name,
        chain: hotel.chain,
        stars: hotel.stars,
        checkInDate,
        checkOutDate,
        nights,
        roomType: roomType || 'Standard'
      },
      pricing: {
        pricePerNight: pricing.pricePerNight,
        nights: pricing.nights,
        totalPrice: pricing.totalPrice,
        currency: 'USD'
      },
      guestName,
      guestEmail,
      message: existingPnr 
        ? `Hotel added to existing booking ${pnr}` 
        : `Hotel booking confirmed with PNR ${pnr}`
    };

  } catch (error) {
    logger.error({ error, sessionId }, 'Hotel booking failed');
    throw error;
  }
}

export default { searchHotels, bookHotel };