import * as cheerio from 'cheerio';
import { FieldSource, PriceStatus, TripContext } from '../types';
import { parsePriceFromText } from './text-patterns';

/**
 * Try to extract price from HTML using various selectors
 */
function tryExtractPriceFromHtml(html: string, $: cheerio.CheerioAPI): number | null {
  // Try various price selectors that Airbnb might use
  const priceSelectors = [
    '[data-testid="price-amount"]',
    'span[class*="Price"]',
    'span[class*="price"]',
    '[itemprop="price"]',
    '._1y6k3r2',
    '._1dss1omb',
  ];
  
  for (const selector of priceSelectors) {
    const element = $(selector).first();
    if (element.length) {
      const text = element.text();
      const price = parsePriceFromText(text);
      if (price !== null) {
        return price;
      }
    }
  }
  
  // Fallback: search entire HTML for price patterns
  const priceFromHtml = parsePriceFromText(html);
  if (priceFromHtml !== null) {
    return priceFromHtml;
  }
  
  return null;
}

/**
 * Extract price with trip context awareness
 * 
 * CRITICAL: Price reliability depends on trip context
 * - With check-in/check-out: Price is for those specific dates
 * - Without trip context: Price may be a base/minimum price
 */
export function extractPrice(
  html: string,
  $: cheerio.CheerioAPI,
  tripContext: TripContext
): { nightly: FieldSource<number | null>; total: FieldSource<number | null>; status: PriceStatus } {
  
  // No trip context = unreliable price
  if (!tripContext.checkIn || !tripContext.checkOut) {
    const extracted = tryExtractPriceFromHtml(html, $);
    
    if (extracted !== null) {
      return {
        nightly: { value: extracted, source: 'text_pattern', confidence: 'low' },
        total: { value: null, source: 'text_pattern', confidence: 'low' },
        status: 'REQUIRES_TRIP_CONTEXT',
      };
    }
    
    return {
      nightly: { value: null, source: 'text_pattern', confidence: 'low' },
      total: { value: null, source: 'text_pattern', confidence: 'low' },
      status: 'UNKNOWN',
    };
  }
  
  // With trip context, try harder to extract
  const extracted = tryExtractPriceFromHtml(html, $);
  
  if (extracted !== null) {
    // Calculate nights for total price
    let total: number | null = null;
    try {
      const checkIn = new Date(tripContext.checkIn);
      const checkOut = new Date(tripContext.checkOut);
      const nights = Math.round((checkOut.getTime() - checkIn.getTime()) / (1000 * 60 * 60 * 24));
      if (nights > 0) {
        total = extracted * nights;
      }
    } catch {
      // Invalid dates, skip total calculation
    }
    
    return {
      nightly: { value: extracted, source: 'text_pattern', confidence: 'medium' },
      total: total !== null 
        ? { value: total, source: 'derived', confidence: 'medium' }
        : { value: null, source: 'text_pattern', confidence: 'low' },
      status: 'EXTRACTED',
    };
  }
  
  return {
    nightly: { value: null, source: 'text_pattern', confidence: 'low' },
    total: { value: null, source: 'text_pattern', confidence: 'low' },
    status: 'UNKNOWN',
  };
}