audible: enforce English locale and fix redirects

Add English-locale enforcement and locale-redirect handling for the Audible integration. Adds Cookie 'lc-acbus=en_US' to Audible client headers and implements handleLocaleRedirect(...) in src/lib/integrations/audible.service.ts to detect non-English culture codes in response URLs, parse Audible's <adbl-toggle-chip> locale picker to obtain the canonical English URL and re-request it, with a fallback URL rewrite (strip culture code + language=en_US). Wire the correction into fetchWithRetry so responses redirected to locale-specific pages are corrected before use. Update documentation (documentation/integrations/audible.md) to describe the behavior and bump package version to 1.0.1.

src/lib/integrations/audible.service.ts

@@ -88,6 +88,7 @@ export class AudibleService {
           'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
           'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
           'Accept-Language': 'en-US,en;q=0.9',
+          'Cookie': 'lc-acbus=en_US', // Force English locale (prevents IP-based language redirect for non-US IPs)
         },
         params: {
           ipRedirectOverride: 'true', // Prevent IP-based region redirects
@@ -107,6 +108,7 @@ export class AudibleService {
           'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36',
           'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
           'Accept-Language': 'en-US,en;q=0.9',
+          'Cookie': 'lc-acbus=en_US', // Force English locale
         },
         params: {
           ipRedirectOverride: 'true',
@@ -116,6 +118,108 @@ export class AudibleService {
     }
   }
 
+  /**
+   * Detect and correct non-English locale pages from Audible.
+   *
+   * Audible uses IP geolocation to serve locale-specific pages by adding culture
+   * codes to URLs (e.g., /adblbestsellers → /es_US/charts/best for Spanish-speaking IPs).
+   * ipRedirectOverride only prevents region redirects (audible.com → audible.co.uk),
+   * NOT language/locale redirects within the same region.
+   *
+   * Strategy (data-driven):
+   * 1. Check response URL for any non-English culture code (xx_YY where xx != 'en')
+   * 2. Parse the page's locale picker (adbl-toggle-chip elements) to find the English URL
+   * 3. Re-request using Audible's own English URL (from the picker's data-value attribute)
+   * 4. Fallback: strip culture code from URL + add language=en_US param if no picker found
+   *
+   * Returns corrected response, or null if no correction needed.
+   */
+  private async handleLocaleRedirect(response: any): Promise<any | null> {
+    try {
+      // Extract final URL after all redirects (Node.js http internals)
+      const finalUrl: string = response.request?.res?.responseUrl ||
+                               response.request?._redirectable?._currentUrl || '';
+
+      if (!finalUrl) return null;
+
+      // Check for non-English culture code in URL path
+      // Culture codes: xx_YY (e.g., es_US, fr_CA, pt_BR, de_DE, ja_JP)
+      // Match in path segment: must follow a / and be followed by / or end-of-path or query string
+      const localeMatch = finalUrl.match(/\/([a-z]{2}_[A-Z]{2})(\/|$|\?)/);
+      if (!localeMatch || localeMatch[1].startsWith('en')) {
+        return null; // No culture code found, or already English
+      }
+
+      const detectedLocale = localeMatch[1];
+      logger.warn(`Detected non-English locale (${detectedLocale}) in Audible response URL: ${finalUrl}`);
+
+      // --- Primary strategy: parse the locale picker from the page HTML ---
+      // Audible pages include a locale picker with <adbl-toggle-chip> web components:
+      //   <adbl-toggle-chip data-locale="en_CA" data-value="/charts/best?language=en_CA">English</adbl-toggle-chip>
+      //   <adbl-toggle-chip data-locale="fr_CA" data-value="/fr_CA/charts/best?language=fr_CA">Français</adbl-toggle-chip>
+      // The English option's data-value gives us the exact correct English URL for this page.
+      const $ = cheerio.load(response.data);
+      const englishChip = $('adbl-toggle-chip[data-locale^="en"]').first();
+
+      if (englishChip.length > 0) {
+        const englishPath = englishChip.attr('data-value');
+        const englishLocale = englishChip.attr('data-locale');
+
+        if (englishPath) {
+          logger.info(`Found English option (${englishLocale}) in locale picker: ${englishPath}`);
+
+          // Re-request using the English URL from the picker
+          // data-value is a relative path (e.g., "/charts/best?language=en_CA")
+          // Client defaults add ipRedirectOverride=true automatically
+          const correctedResponse = await this.client.get(englishPath);
+
+          // Verify the correction actually resolved to English
+          const correctedUrl: string = correctedResponse.request?.res?.responseUrl ||
+                                       correctedResponse.request?._redirectable?._currentUrl || '';
+          if (correctedUrl) {
+            const verifyMatch = correctedUrl.match(/\/([a-z]{2}_[A-Z]{2})(\/|$|\?)/);
+            if (verifyMatch && !verifyMatch[1].startsWith('en')) {
+              logger.warn(`Locale correction incomplete — corrected URL still contains non-English locale (${verifyMatch[1]}): ${correctedUrl}`);
+            } else {
+              logger.info(`Locale correction successful (${detectedLocale} → ${englishLocale})`);
+            }
+          }
+
+          return correctedResponse;
+        }
+
+        logger.warn('English locale chip found but missing data-value attribute');
+      } else {
+        logger.warn('No locale picker found on page, attempting fallback URL rewrite');
+      }
+
+      // --- Fallback strategy: URL rewrite ---
+      // Strip the non-English culture code from the path and add language=en_US param.
+      // This mirrors the locale picker pattern: English URLs have no prefix + language param.
+      try {
+        const urlObj = new URL(finalUrl);
+        urlObj.pathname = urlObj.pathname.replace(`/${detectedLocale}`, '');
+        urlObj.searchParams.set('language', 'en_US');
+
+        // Build relative path (client will prepend baseURL)
+        const fallbackPath = urlObj.pathname + urlObj.search;
+        logger.info(`Fallback: re-requesting with URL rewrite: ${fallbackPath}`);
+
+        return await this.client.get(fallbackPath);
+      } catch (urlError) {
+        logger.warn('Fallback URL rewrite failed', {
+          error: urlError instanceof Error ? urlError.message : String(urlError),
+        });
+      }
+    } catch (error) {
+      logger.debug('Locale correction failed entirely, using original response', {
+        error: error instanceof Error ? error.message : String(error),
+      });
+    }
+
+    return null;
+  }
+
   /**
    * Fetch with retry logic and exponential backoff
    * Retries on network errors and rate limiting (503, 429)
@@ -129,7 +233,10 @@ export class AudibleService {
 
     for (let attempt = 0; attempt <= maxRetries; attempt++) {
       try {
-        return await this.client.get(url, config);
+        const response = await this.client.get(url, config);
+
+        // Check if redirected to non-English locale (e.g., /es_US/) and correct it
+        return await this.handleLocaleRedirect(response) || response;
       } catch (error: any) {
         lastError = error;
         const status = error.response?.status;