/**
 * eBay Content Script
 * Wird auf eBay-Seiten ausgeführt und extrahiert Verkäufer-/Shop-Daten aus dem DOM
 */

// Message Listener für Parsing-Anfragen
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
  if (message.action === "PARSE_EBAY") {
    try {
      const parsedData = parseEbayPage();
      sendResponse({ ok: true, data: parsedData });
    } catch (error) {
      // Niemals unhandled throws - immer graceful response
      sendResponse({ 
        ok: true, 
        data: {
          sellerId: "",
          shopName: "",
          market: extractMarketFromHostname(),
          status: "unknown",
          stats: {}
        }
      });
    }
    return true; // async response
  }
});

/**
 * Extrahiert Marktplatz aus hostname
 * @returns {string} Market Code (z.B. "DE", "US", "UK")
 */
function extractMarketFromHostname() {
  try {
    const hostname = window.location.hostname.toLowerCase();
    
    // eBay Domain-Patterns
    if (hostname.includes('.de') || hostname.includes('ebay.de')) {
      return 'DE';
    }
    if (hostname.includes('.com') && !hostname.includes('.uk')) {
      return 'US';
    }
    if (hostname.includes('.uk') || hostname.includes('ebay.co.uk')) {
      return 'UK';
    }
    if (hostname.includes('.fr') || hostname.includes('ebay.fr')) {
      return 'FR';
    }
    if (hostname.includes('.it') || hostname.includes('ebay.it')) {
      return 'IT';
    }
    if (hostname.includes('.es') || hostname.includes('ebay.es')) {
      return 'ES';
    }
    if (hostname.includes('.nl') || hostname.includes('ebay.nl')) {
      return 'NL';
    }
    if (hostname.includes('.at') || hostname.includes('ebay.at')) {
      return 'AT';
    }
    if (hostname.includes('.ch') || hostname.includes('ebay.ch')) {
      return 'CH';
    }
    
    // Fallback: erster Teil der Domain nach "ebay."
    const match = hostname.match(/ebay\.([a-z]{2,3})/);
    if (match && match[1]) {
      return match[1].toUpperCase();
    }
    
    return 'US'; // Default
  } catch (e) {
    return 'US';
  }
}

/**
 * Extrahiert Seller ID aus URL oder DOM
 * @returns {string} Seller ID
 */
function extractSellerId() {
  try {
    // Methode 1: URL-Patterns
    const url = window.location.href;
    const urlLower = url.toLowerCase();
    
    // Pattern: /usr/username oder /str/storename
    const usrMatch = url.match(/\/usr\/([^\/\?]+)/i);
    if (usrMatch && usrMatch[1]) {
      return usrMatch[1].trim();
    }
    
    const strMatch = url.match(/\/str\/([^\/\?]+)/i);
    if (strMatch && strMatch[1]) {
      return strMatch[1].trim();
    }
    
    // Methode 2: DOM-Elemente suchen
    // Suche nach verschiedenen Selektoren, die Seller-ID enthalten könnten
    const possibleSelectors = [
      '[data-testid*="seller"]',
      '.seller-username',
      '.member-info-username',
      '[class*="seller-id"]',
      '[class*="username"]',
      '[id*="seller"]'
    ];
    
    for (const selector of possibleSelectors) {
      try {
        const element = document.querySelector(selector);
        if (element) {
          const text = element.textContent?.trim();
          if (text && text.length > 0 && text.length < 100) {
            return text;
          }
        }
      } catch (e) {
        // Continue to next selector
      }
    }
    
    // Methode 3: Meta-Tags
    try {
      const metaSeller = document.querySelector('meta[property*="seller"], meta[name*="seller"]');
      if (metaSeller && metaSeller.content) {
        return metaSeller.content.trim();
      }
    } catch (e) {
      // Continue
    }
    
    return ""; // Nicht gefunden
  } catch (e) {
    return "";
  }
}

/**
 * Extrahiert Shop Name aus DOM
 * @returns {string} Shop Name
 */
function extractShopName() {
  try {
    // Methode 1: Spezifische Selektoren versuchen
    const shopNameSelectors = [
      'h1.shop-name',
      '.store-name',
      '[data-testid="store-name"]',
      '.store-title',
      '[class*="shop-name"]',
      '[class*="store-title"]',
      'h1[class*="store"]',
      'h1[class*="shop"]'
    ];
    
    for (const selector of shopNameSelectors) {
      try {
        const element = document.querySelector(selector);
        if (element) {
          const text = element.textContent?.trim();
          if (text && text.length > 0) {
            return text;
          }
        }
      } catch (e) {
        // Continue to next selector
      }
    }
    
    // Methode 2: document.title parsen
    try {
      const title = document.title || "";
      // Versuche Muster wie "Shop Name | eBay" zu extrahieren
      const titleMatch = title.match(/^(.+?)\s*[\|\-]\s*eBay/i);
      if (titleMatch && titleMatch[1]) {
        return titleMatch[1].trim();
      }
      // Wenn Titel einfach genug ist, verwende ihn direkt
      if (title && title.length < 100 && !title.toLowerCase().includes('ebay')) {
        return title.trim();
      }
    } catch (e) {
      // Continue
    }
    
    // Methode 3: h1 Tag als Fallback
    try {
      const h1 = document.querySelector('h1');
      if (h1) {
        const text = h1.textContent?.trim();
        if (text && text.length > 0 && text.length < 200) {
          return text;
        }
      }
    } catch (e) {
      // Continue
    }
    
    return ""; // Nicht gefunden
  } catch (e) {
    return "";
  }
}

/**
 * Extrahiert Stats aus DOM (Feedback Score, Positive Rate, etc.)
 * @returns {object} Stats Objekt
 */
function extractStats() {
  const stats = {};
  
  try {
    const pageText = document.body?.textContent || "";
    
    // Feedback Score
    try {
      const feedbackScorePatterns = [
        /feedback\s*score[:\s]+(\d+)/i,
        /(?:score|bewertung)[:\s]+(\d+)/i,
        /(\d+)\s*feedback/i
      ];
      
      for (const pattern of feedbackScorePatterns) {
        const match = pageText.match(pattern);
        if (match && match[1]) {
          const score = parseInt(match[1], 10);
          if (!isNaN(score) && score >= 0) {
            stats.feedbackScore = score;
            break;
          }
        }
      }
    } catch (e) {
      // Continue
    }
    
    // Positive Rate (%)
    try {
      const positiveRatePatterns = [
        /positive[:\s]+(\d+\.?\d*)\s*%/i,
        /(\d+\.?\d*)\s*%\s*positive/i,
        /(?:rate|quote)[:\s]+(\d+\.?\d*)\s*%/i
      ];
      
      for (const pattern of positiveRatePatterns) {
        const match = pageText.match(pattern);
        if (match && match[1]) {
          const rate = parseFloat(match[1]);
          if (!isNaN(rate) && rate >= 0 && rate <= 100) {
            stats.positiveRate = rate;
            break;
          }
        }
      }
    } catch (e) {
      // Continue
    }
    
    // Feedback Count
    try {
      const feedbackCountPatterns = [
        /(\d+)\s*(?:bewertungen|ratings|feedbacks?)/i,
        /(?:count|anzahl)[:\s]+(\d+)/i
      ];
      
      for (const pattern of feedbackCountPatterns) {
        const match = pageText.match(pattern);
        if (match && match[1]) {
          const count = parseInt(match[1], 10);
          if (!isNaN(count) && count >= 0) {
            stats.feedbackCount = count;
            break;
          }
        }
      }
    } catch (e) {
      // Continue
    }
    
    // Items for Sale
    try {
      const itemsPatterns = [
        /items?\s*(?:for\s*)?sale[:\s]+(\d+)/i,
        /(\d+)\s*artikel/i,
        /(\d+)\s*(?:items?|artikel)\s*(?:for\s*)?sale/i
      ];
      
      for (const pattern of itemsPatterns) {
        const match = pageText.match(pattern);
        if (match && match[1]) {
          const items = parseInt(match[1], 10);
          if (!isNaN(items) && items >= 0) {
            stats.itemsForSale = items;
            break;
          }
        }
      }
    } catch (e) {
      // Continue
    }
    
    // Member Since
    try {
      const memberSincePatterns = [
        /member\s*since[:\s]+(\d{1,2}[\/\-\.]\d{1,2}[\/\-\.]\d{2,4})/i,
        /mitglied\s*seit[:\s]+(\d{1,2}[\/\-\.]\d{1,2}[\/\-\.]\d{2,4})/i,
        /(?:since|seit)[:\s]+(\d{4})/i
      ];
      
      for (const pattern of memberSincePatterns) {
        const match = pageText.match(pattern);
        if (match && match[1]) {
          stats.memberSince = match[1].trim();
          break;
        }
      }
    } catch (e) {
      // Continue
    }
    
  } catch (e) {
    // Return empty stats object
  }
  
  return stats;
}

/**
 * Haupt-Parsing-Funktion
 * @returns {object} Parsed eBay Account Data
 */
function parseEbayPage() {
  try {
    const sellerId = extractSellerId();
    const shopName = extractShopName();
    const market = extractMarketFromHostname();
    const stats = extractStats();
    
    // Status bestimmen: "active" wenn wir mindestens Shop Name oder Seller ID haben
    const status = (sellerId || shopName) ? "active" : "unknown";
    
    return {
      sellerId: sellerId || "",
      shopName: shopName || "",
      market: market,
      status: status,
      stats: stats
    };
  } catch (error) {
    // Graceful fallback
    return {
      sellerId: "",
      shopName: "",
      market: extractMarketFromHostname(),
      status: "unknown",
      stats: {}
    };
  }
}