import 'dart:async';
import 'dart:collection';
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';

abstract class ILinkExtractionService {
  Future<String?> extractVideoUrl(String pageUrl);
}

class LinkExtractionService implements ILinkExtractionService {

  @override
  Future<String?> extractVideoUrl(String pageUrl) async {
    // 1. Zaten direkt bir video linkiyse hemen döndür
    if (_isVideoUrl(pageUrl)) return pageUrl;

    // 2. hdfilmizle.so gibi bilinen siteleri özel olarak işle
    if (_isHdFilmIzle(pageUrl)) {
      debugPrint("EXTRACTION: Detected hdfilmizle.so — using specialized extractor");
      return _extractFromHdFilmIzle(pageUrl);
    }

    // 3. Genel amaçlı sniffer (diğer siteler için)
    return _extractGeneric(pageUrl);
  }

  // ============================================================
  //  hdfilmizle.so Özel Extractor
  // ============================================================

  bool _isHdFilmIzle(String url) {
    final lower = url.toLowerCase();
    return lower.contains('hdfilmizle.so') ||
        lower.contains('hdfilmizle.co') ||
        lower.contains('hdfilmizle.org') ||
        lower.contains('hdfilmizle.net');
  }

  /// hdfilmizle.so için 2 aşamalı extraction:
  /// Aşama 1: Ana sayfadan "parts" array'ini çıkar → iframe URL al
  /// Aşama 2: iframe (vidrame.pro) sayfasından EE.dd() ile m3u8 URL decode et
  Future<String?> _extractFromHdFilmIzle(String pageUrl) async {
    // AŞAMA 1: Ana sayfadan iframe URL'lerini çıkar
    debugPrint("EXTRACTION [PHASE 1]: Loading main page to extract iframe URLs...");
    final iframeUrl = await _extractIframeUrl(pageUrl);

    if (iframeUrl == null) {
      debugPrint("EXTRACTION [PHASE 1]: No iframe URL found, falling back to generic extractor");
      return _extractGeneric(pageUrl);
    }

    debugPrint("EXTRACTION [PHASE 1]: Found iframe URL: $iframeUrl");

    // AŞAMA 2: iframe sayfasından video URL'yi decode et
    debugPrint("EXTRACTION [PHASE 2]: Loading iframe to decode video URL...");
    final videoUrl = await _extractVideoFromIframe(iframeUrl);

    if (videoUrl != null) {
      debugPrint("EXTRACTION [PHASE 2]: SUCCESS! Video URL: $videoUrl");
      return videoUrl;
    }

    debugPrint("EXTRACTION [PHASE 2]: Failed, falling back to generic extractor");
    return _extractGeneric(pageUrl);
  }

  /// Aşama 1: hdfilmizle.so ana sayfasından "parts" JavaScript değişkenini parse eder
  /// ve ilk iframe URL'sini döndürür.
  Future<String?> _extractIframeUrl(String pageUrl) async {
    final completer = Completer<String?>();
    HeadlessInAppWebView? webView;
    Timer? timeout;

    void cleanup() {
      timeout?.cancel();
      webView?.dispose();
      webView = null;
    }

    timeout = Timer(const Duration(seconds: 12), () {
      if (!completer.isCompleted) {
        debugPrint("EXTRACTION [PHASE 1]: Timeout");
        cleanup();
        completer.complete(null);
      }
    });

    // JS: "parts" array'ini bul ve iframe src'lerini çıkar
    final extractScript = UserScript(
      source: '''
        (function() {
          if (window.__phase1Injected) return;
          window.__phase1Injected = true;

          // parts array'inden iframe URL çıkar
          window.__extractIframeUrls = function() {
            try {
              // 1. Sayfadaki tüm script taglarını tara
              var scripts = document.querySelectorAll('script');
              for (var i = 0; i < scripts.length; i++) {
                var text = scripts[i].textContent || scripts[i].innerText || '';
                
                // "let parts" veya "var parts" değişkenini bul
                var partsMatch = text.match(/(?:let|var|const)\\s+parts\\s*=\\s*(\\[.*?\\]);/s);
                if (partsMatch) {
                  try {
                    var partsData = eval('(' + partsMatch[1] + ')');
                    var iframeUrls = [];
                    
                    for (var j = 0; j < partsData.length; j++) {
                      var part = partsData[j];
                      var data = part.data || part.html || '';
                      
                      // iframe src'yi çıkar
                      var iframeMatch = data.match(/src=["']([^"']+)["']/i);
                      if (iframeMatch) {
                        iframeUrls.push({
                          title: part.title || part.name || ('Part ' + j),
                          url: iframeMatch[1]
                        });
                      }
                    }
                    
                    if (iframeUrls.length > 0) {
                      window.flutter_inappwebview.callHandler('iframeUrlsFound', JSON.stringify(iframeUrls));
                      return;
                    }
                  } catch(e) {
                    console.log('PHASE1: Error parsing parts: ' + e);
                  }
                }
              }

              // 2. Fallback: Sayfadaki mevcut iframe'leri doğrudan kontrol et
              var iframes = document.querySelectorAll('iframe');
              var directUrls = [];
              for (var k = 0; k < iframes.length; k++) {
                var src = iframes[k].src || iframes[k].getAttribute('data-src') || '';
                if (src && src.indexOf('vidrame') > -1 || src.indexOf('vidmoly') > -1 || 
                    src.indexOf('closeload') > -1 || src.indexOf('rapidezvous') > -1 ||
                    src.indexOf('player') > -1) {
                  directUrls.push({ title: 'iframe-' + k, url: src });
                }
              }
              if (directUrls.length > 0) {
                window.flutter_inappwebview.callHandler('iframeUrlsFound', JSON.stringify(directUrls));
                return;
              }
              
              // 3. Fallback: data-url veya benzeri attribute'lerden
              var playerElements = document.querySelectorAll('[data-url], [data-src], [data-iframe]');
              var attrUrls = [];
              for (var m = 0; m < playerElements.length; m++) {
                var u = playerElements[m].getAttribute('data-url') || 
                        playerElements[m].getAttribute('data-src') || 
                        playerElements[m].getAttribute('data-iframe') || '';
                if (u && u.startsWith('http')) {
                  attrUrls.push({ title: 'data-' + m, url: u });
                }
              }
              if (attrUrls.length > 0) {
                window.flutter_inappwebview.callHandler('iframeUrlsFound', JSON.stringify(attrUrls));
              }
              
            } catch(e) {
              console.log('PHASE1: Top-level error: ' + e);
            }
          };
        })();
      ''',
      injectionTime: UserScriptInjectionTime.AT_DOCUMENT_START,
      forMainFrameOnly: true,
    );

    webView = HeadlessInAppWebView(
      initialUrlRequest: URLRequest(url: WebUri(pageUrl)),
      initialUserScripts: UnmodifiableListView<UserScript>([extractScript]),
      initialSettings: InAppWebViewSettings(
        javaScriptEnabled: true,
        mediaPlaybackRequiresUserGesture: true,
        mixedContentMode: MixedContentMode.MIXED_CONTENT_ALWAYS_ALLOW,
        supportMultipleWindows: false,
        javaScriptCanOpenWindowsAutomatically: false,
        userAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
      ),
      onWebViewCreated: (controller) {
        controller.addJavaScriptHandler(
          handlerName: 'iframeUrlsFound',
          callback: (args) {
            if (args.isNotEmpty && !completer.isCompleted) {
              try {
                final List<dynamic> urls = jsonDecode(args[0].toString());
                if (urls.isNotEmpty) {
                  final firstUrl = urls[0]['url']?.toString();
                  debugPrint("EXTRACTION [PHASE 1]: Found ${urls.length} iframe(s), first: $firstUrl");
                  cleanup();
                  completer.complete(firstUrl);
                }
              } catch (e) {
                debugPrint("EXTRACTION [PHASE 1]: JSON parse error: $e");
              }
            }
          },
        );
      },
      onReceivedServerTrustAuthRequest: (controller, challenge) async {
        return ServerTrustAuthResponse(action: ServerTrustAuthResponseAction.PROCEED);
      },
      onLoadStop: (controller, url) async {
        debugPrint("EXTRACTION [PHASE 1]: Page loaded: $url");
        
        // Sayfa yüklendikten sonra extraction fonksiyonunu çalıştır
        for (int i = 0; i < 5; i++) {
          if (completer.isCompleted) break;
          await Future.delayed(const Duration(milliseconds: 800));
          if (completer.isCompleted) break;

          try {
            await controller.evaluateJavascript(
              source: "if(window.__extractIframeUrls) window.__extractIframeUrls();",
            );
          } catch (e) {
            debugPrint("EXTRACTION [PHASE 1]: JS execution error: $e");
          }
        }
      },
    );

    await webView?.run();
    return completer.future;
  }

  /// Aşama 2: vidrame.pro iframe sayfasından video URL'yi decode eder.
  /// Sayfa JWPlayer kullanır ve video kaynağı EE.dd() fonksiyonu ile şifrelenir.
  /// Strateji: Sayfanın kendi JS'ini çalıştırarak decode edilmiş URL'yi alıyoruz.
  Future<String?> _extractVideoFromIframe(String iframeUrl) async {
    final completer = Completer<String?>();
    HeadlessInAppWebView? webView;
    Timer? timeout;

    void cleanup() {
      timeout?.cancel();
      webView?.dispose();
      webView = null;
    }

    void handleFoundUrl(String url) {
      if (!completer.isCompleted) {
        cleanup();
        completer.complete(url);
      }
    }

    timeout = Timer(const Duration(seconds: 15), () {
      if (!completer.isCompleted) {
        debugPrint("EXTRACTION [PHASE 2]: Timeout");
        cleanup();
        completer.complete(null);
      }
    });

    // JS: vidrame.pro sayfasından video URL'yi çıkar
    // EE.dd() fonksiyonu sayfada zaten tanımlı, biz sadece configs.sources[0].file değerini alıyoruz
    final decodeScript = UserScript(
      source: '''
        (function() {
          if (window.__phase2Injected) return;
          window.__phase2Injected = true;

          console.log("PHASE2: Injected into: " + window.location.href);

          // Yöntem 1: Network request'leri yakala (en güvenilir)
          function reportUrl(url) {
            if (url && (url.includes('.m3u8') || url.includes('.mp4'))) {
              console.log("PHASE2: Found video URL via intercept: " + url);
              window.flutter_inappwebview.callHandler('videoUrlFound', url);
            }
          }

          var oldOpen = XMLHttpRequest.prototype.open;
          XMLHttpRequest.prototype.open = function(method, url) {
            reportUrl(url);
            return oldOpen.apply(this, arguments);
          };

          var oldFetch = window.fetch;
          window.fetch = function() {
            var url = (arguments[0] instanceof Request) ? arguments[0].url : arguments[0];
            if (url) reportUrl(url.toString());
            return oldFetch.apply(this, arguments);
          };

          // Yöntem 2: JWPlayer configs'ten doğrudan çıkar
          window.__extractFromJwPlayer = function() {
            try {
              // jwplayer instance'ını kontrol et
              if (typeof jwplayer !== 'undefined') {
                var pl = jwplayer();
                if (pl && pl.getPlaylistItem) {
                  var item = pl.getPlaylistItem();
                  if (item && item.file) {
                    reportUrl(item.file);
                    return true;
                  }
                  if (item && item.sources) {
                    for (var i = 0; i < item.sources.length; i++) {
                      if (item.sources[i].file) {
                        reportUrl(item.sources[i].file);
                        return true;
                      }
                    }
                  }
                }
              }
            } catch(e) {
              console.log("PHASE2: JWPlayer check error: " + e);
            }

            try {
              // configs variable'ını doğrudan kontrol et
              if (typeof configs !== 'undefined' && configs.sources) {
                for (var j = 0; j < configs.sources.length; j++) {
                  if (configs.sources[j].file) {
                    reportUrl(configs.sources[j].file);
                    return true;
                  }
                }
              }
            } catch(e) {
              console.log("PHASE2: configs check error: " + e);
            }

            try {
              // EE.dd decode fonksiyonunu doğrudan dene
              if (typeof EE !== 'undefined' && EE.dd) {
                // Sayfadaki tüm scriptleri tara ve EE.dd(...) çağrılarını bul
                var scripts = document.querySelectorAll('script');
                for (var k = 0; k < scripts.length; k++) {
                  var text = scripts[k].textContent || '';
                  var matches = text.match(/EE\\.dd\\(["']([^"']+)["']\\)/g);
                  if (matches) {
                    for (var m = 0; m < matches.length; m++) {
                      var encoded = matches[m].match(/EE\\.dd\\(["']([^"']+)["']\\)/);
                      if (encoded && encoded[1]) {
                        try {
                          var decoded = EE.dd(encoded[1]);
                          if (decoded) reportUrl(decoded);
                        } catch(e2) {}
                      }
                    }
                  }
                }
              }
            } catch(e) {
              console.log("PHASE2: EE.dd scan error: " + e);
            }

            try {
              // HTML içinde doğrudan m3u8/mp4 regex tara
              var html = document.documentElement.innerHTML;
              var match = html.match(/https?:\\/\\/[^"'\\s<>]+\\.(m3u8|mp4)[^"'\\s<>]*/i);
              if (match) {
                reportUrl(match[0]);
                return true;
              }
            } catch(e) {}

            try {
              // Video elementlerini kontrol et
              document.querySelectorAll('video').forEach(function(v) {
                if (v.src && v.src.length > 5) reportUrl(v.src);
                v.querySelectorAll('source').forEach(function(s) {
                  if (s.src) reportUrl(s.src);
                });
              });
            } catch(e) {}

            return false;
          };
        })();
      ''',
      injectionTime: UserScriptInjectionTime.AT_DOCUMENT_START,
      forMainFrameOnly: false,
    );

    webView = HeadlessInAppWebView(
      initialUrlRequest: URLRequest(url: WebUri(iframeUrl)),
      initialUserScripts: UnmodifiableListView<UserScript>([decodeScript]),
      initialSettings: InAppWebViewSettings(
        javaScriptEnabled: true,
        mediaPlaybackRequiresUserGesture: false,
        mixedContentMode: MixedContentMode.MIXED_CONTENT_ALWAYS_ALLOW,
        supportMultipleWindows: false,
        javaScriptCanOpenWindowsAutomatically: false,
        useShouldInterceptRequest: true,
        userAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
      ),
      onWebViewCreated: (controller) {
        controller.addJavaScriptHandler(
          handlerName: 'videoUrlFound',
          callback: (args) {
            if (args.isNotEmpty) {
              handleFoundUrl(args[0].toString());
            }
          },
        );
      },
      onReceivedServerTrustAuthRequest: (controller, challenge) async {
        return ServerTrustAuthResponse(action: ServerTrustAuthResponseAction.PROCEED);
      },
      shouldInterceptRequest: (controller, request) async {
        final url = request.url.toString();
        if (_isVideoUrl(url)) {
          handleFoundUrl(url);
        }
        return null;
      },
      onLoadStop: (controller, url) async {
        debugPrint("EXTRACTION [PHASE 2]: iframe loaded: $url");

        // JWPlayer'ın yüklenmesini bekle ve video URL'yi çıkar
        for (int i = 0; i < 10; i++) {
          if (completer.isCompleted) break;
          await Future.delayed(const Duration(seconds: 1));
          if (completer.isCompleted) break;

          try {
            await controller.evaluateJavascript(
              source: "if(window.__extractFromJwPlayer) window.__extractFromJwPlayer();",
            );
          } catch (e) {
            debugPrint("EXTRACTION [PHASE 2]: JS execution error: $e");
          }
        }
      },
    );

    await webView?.run();
    return completer.future;
  }

  // ============================================================
  //  Dart tarafında EE.dd() decode (fallback olarak)
  // ============================================================

  /// vidrame.pro'nun EE.dd() şifre çözme algoritması:
  /// 1. URL-safe base64 → standart base64 dönüştür
  /// 2. Base64 decode
  /// 3. ROT13 uygula
  /// 4. String reverse
  static String? decodEEdd(String encoded) {
    try {
      // URL-safe base64 → standart base64
      String s = encoded.replaceAll('-', '+').replaceAll('_', '/');
      while (s.length % 4 != 0) {
        s += '=';
      }

      // Base64 decode
      final decoded = utf8.decode(base64Decode(s));

      // ROT13
      final rot13 = _rot13(decoded);

      // String reverse
      return rot13.split('').reversed.join('');
    } catch (e) {
      debugPrint("decodEEdd error: $e");
      return null;
    }
  }

  /// ROT13 dönüşümü (harfler ve rakamlar dahil, vidrame'nin özel versiyonu)
  static String _rot13(String input) {
    final buffer = StringBuffer();
    for (int i = 0; i < input.length; i++) {
      final c = input.codeUnitAt(i);

      if (c >= 65 && c <= 90) {
        // A-Z
        buffer.writeCharCode(((c - 65 + 13) % 26) + 65);
      } else if (c >= 97 && c <= 122) {
        // a-z
        buffer.writeCharCode(((c - 97 + 13) % 26) + 97);
      } else if (c >= 48 && c <= 57) {
        // 0-9
        buffer.writeCharCode(((c - 48 + 13) % 10) + 48);
      } else {
        buffer.writeCharCode(c);
      }
    }
    return buffer.toString();
  }

  // ============================================================
  //  Genel Amaçlı Sniffer (Fallback)
  // ============================================================

  Future<String?> _extractGeneric(String pageUrl) async {
    final completer = Completer<String?>();
    Timer? timeoutTimer;
    HeadlessInAppWebView? headlessWebView;

    void cleanup() {
      timeoutTimer?.cancel();
      headlessWebView?.dispose();
      headlessWebView = null;
    }

    void handleFoundUrl(String url) {
      if (!completer.isCompleted) {
        debugPrint("EXTRACTION: SUCCESS! Found: $url");
        cleanup();
        completer.complete(url);
      }
    }

    // Zaman aşımı (15 saniye)
    timeoutTimer = Timer(const Duration(seconds: 15), () {
      if (!completer.isCompleted) {
        debugPrint("EXTRACTION: Timeout - no video URL found");
        cleanup();
        completer.complete(null);
      }
    });

    // UserScript: JS Kodunu Iframe'ler dahil tüm sayfalara DOM yüklenmeden ENJEKTE EDİYORUZ
    final snifferScript = UserScript(
      source: '''
        (function() {
          if (window.snifferInjected) return;
          window.snifferInjected = true;

          console.log("SNIFFER: Injected into frame: " + window.location.href);

          function reportUrl(url) {
            if (url && (url.includes('.m3u8') || url.includes('.mp4'))) {
              window.flutter_inappwebview.callHandler('foundVideoUrl', url);
            }
          }

          // 1. Override XMLHttpRequest
          var oldOpen = XMLHttpRequest.prototype.open;
          XMLHttpRequest.prototype.open = function(method, url) {
            reportUrl(url);
            return oldOpen.apply(this, arguments);
          };

          // 2. Override Fetch
          var oldFetch = window.fetch;
          window.fetch = function() {
            var url = (arguments[0] instanceof Request) ? arguments[0].url : arguments[0];
            if (url) reportUrl(url.toString());
            return oldFetch.apply(this, arguments);
          };

          // 3. Oynatma Butonlarına Tıklama (Tüm iframe'lerde çalışacak)
          window.clickPlayButtons = function() {
            var selectors = [
              '.play-that-video', '.play-button', '.vjs-big-play-button', 
              '[aria-label="Play"]', '.ytp-large-play-button', '.play-icon', 
              '#play', '.player-play', '.jw-display-icon-container',
              'div[class*="play"]', 'button[class*="play"]', 'svg[class*="play"]'
            ];
            
            selectors.forEach(function(sel) {
              try {
                document.querySelectorAll(sel).forEach(function(el) {
                  if (el.offsetWidth > 0 || el.offsetHeight > 0) {
                    el.click();
                  }
                });
              } catch(e) {}
            });

            // Video etiketlerini direkt kontrol et
            document.querySelectorAll('video').forEach(function(v) {
              if (v.src && v.src.length > 5) reportUrl(v.src);
              v.querySelectorAll('source').forEach(function(s) {
                 if (s.src) reportUrl(s.src);
              });
            });
          };

          // HTML içindeki linkleri Regex ile tara
          var scanInterval = setInterval(function() {
            var html = document.documentElement.innerHTML;
            var match = html.match(/https?:\\/\\/[^"'\\s<>]+\\.(m3u8|mp4)[^"'\\s<>]*/i);
            if (match) reportUrl(match[0]);
          }, 1500);

        })();
      ''',
      injectionTime: UserScriptInjectionTime.AT_DOCUMENT_START, // Sayfa açılmadan hemen önce
      forMainFrameOnly: false, // ÇOK ÖNEMLİ: Iframe'lerin içine girmesi için false olmalı!
    );

    headlessWebView = HeadlessInAppWebView(
      initialUrlRequest: URLRequest(url: WebUri(pageUrl)),
      initialUserScripts: UnmodifiableListView<UserScript>([snifferScript]),
      initialSettings: InAppWebViewSettings(
        javaScriptEnabled: true,
        isInspectable: true,
        mediaPlaybackRequiresUserGesture: false, // ÇOK ÖNEMLİ: Videoların tıklanmadan yüklenmesine izin ver
        mixedContentMode: MixedContentMode.MIXED_CONTENT_ALWAYS_ALLOW,
        supportMultipleWindows: false,
        javaScriptCanOpenWindowsAutomatically: false,
        useShouldInterceptRequest: true,
        userAgent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
      ),
      onWebViewCreated: (controller) {
        // JS'den gelen sinyali dinle
        controller.addJavaScriptHandler(handlerName: 'foundVideoUrl', callback: (args) {
          if (args.isNotEmpty) {
            handleFoundUrl(args[0].toString());
          }
        });
      },
      onReceivedServerTrustAuthRequest: (controller, challenge) async {
        return ServerTrustAuthResponse(action: ServerTrustAuthResponseAction.PROCEED);
      },
      shouldInterceptRequest: (controller, request) async {
        final url = request.url.toString();
        if (_isVideoUrl(url)) {
          handleFoundUrl(url);
        }
        return null;
      },
      onLoadStop: (controller, url) async {
        debugPrint("EXTRACTION: Page loaded: $url");
        
        // JS yüklenmiş mi diye kontrol et ve butonlara tıkla
        for (int i = 0; i < 8; i++) {
          if (completer.isCompleted) break;
          await Future.delayed(const Duration(seconds: 1));
          if (completer.isCompleted) break;
          
          try {
            // WebView kapanmışsa hata fırlatmasını engellemek için try-catch
            await controller.evaluateJavascript(source: "if(window.clickPlayButtons) window.clickPlayButtons();");
          } catch (e) {
            debugPrint("WebView disposed before javascript execution.");
          }
        }
      },
    );

    await headlessWebView?.run();
    return completer.future;
  }

  // ============================================================
  //  Yardımcı Fonksiyonlar
  // ============================================================

  bool _isVideoUrl(String url) {
    final lower = url.toLowerCase();
    if (lower.startsWith('data:') || lower.length < 10) return false;
    
    // Analitik veya reklam linklerini es geç
    if (lower.contains('google.com') || lower.contains('gstatic.com') || lower.contains('analytics')) return false;

    return lower.contains('.m3u8') ||
        lower.contains('.mp4') ||
        lower.contains('.mkv') ||
        lower.contains('/hls/') ||
        lower.contains('master.m3u8') ||
        lower.contains('index.m3u8') ||
        lower.contains('playlist.m3u8');
  }
}