refactor: remove unused parameters and redundant errors

api/playback/allanime_client.go

@@ -464,8 +464,8 @@ func decryptTobeparsed(encoded string) ([]byte, error) {
 		}
 
 		if version == 1 {
-			plainText, err := tryDecryptCTR(block, iv, cipherText)
-			if err == nil && json.Valid(plainText) {
+			plainText := tryDecryptCTR(block, iv, cipherText)
+			if json.Valid(plainText) {
 				return plainText, nil
 			}
 		}
@@ -484,13 +484,13 @@ func decryptTobeparsed(encoded string) ([]byte, error) {
 	return nil, fmt.Errorf("decryption failed")
 }
 
-func tryDecryptCTR(block cipher.Block, iv []byte, cipherText []byte) ([]byte, error) {
+func tryDecryptCTR(block cipher.Block, iv []byte, cipherText []byte) []byte {
 	ctrIV := append([]byte{}, iv...)
 	ctrIV = append(ctrIV, 0x00, 0x00, 0x00, 0x02)
 	ctr := cipher.NewCTR(block, ctrIV)
 	plainText := make([]byte, len(cipherText))
 	ctr.XORKeyStream(plainText, cipherText)
-	return plainText, nil
+	return plainText
 }
 
 // Search queries AllAnime for shows matching the given search term.

api/playback/allanime_client_test.go

@@ -430,11 +430,7 @@ func TestTryDecryptCTR(t *testing.T) {
 		iv := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b}
 		cipherText := []byte("test plaintext  ")
 
-		plainText, err := tryDecryptCTR(block, iv, cipherText)
-		if err != nil {
-			t.Errorf("tryDecryptCTR error: %v", err)
-		}
-
+		plainText := tryDecryptCTR(block, iv, cipherText)
 		_ = plainText
 	})
 }

api/playback/provider_extractor.go

@@ -58,11 +58,11 @@ func (e *providerExtractor) ExtractVideoLinks(ctx context.Context, providerPath
 		return nil, fmt.Errorf("read provider response: %w", err)
 	}
 
-	return e.parseProviderResponse(ctx, string(body))
+	return e.parseProviderResponse(ctx, string(body)), nil
 }
 
 // parseProviderResponse extracts stream sources from provider JSON response.
-func (e *providerExtractor) parseProviderResponse(ctx context.Context, response string) ([]StreamSource, error) {
+func (e *providerExtractor) parseProviderResponse(ctx context.Context, response string) []StreamSource {
 	sources := make([]StreamSource, 0)
 	providerReferer := e.referer
 
@@ -146,7 +146,7 @@ func (e *providerExtractor) parseProviderResponse(ctx context.Context, response
 		}
 	}
 
-	return sources, nil
+	return sources
 }
 
 // parseM3U8 fetches a master playlist and extracts individual stream URLs with bandwidth-derived quality.

api/playback/service_proxy.go

@@ -47,7 +47,7 @@ func (s *Service) ProxyStream(ctx context.Context, targetURL string, referer str
 			continue
 		}
 
-		return s.handleProxyResponse(ctx, resp, targetURL, referer, rangeHeader)
+		return s.handleProxyResponse(ctx, resp, targetURL, referer)
 	}
 
 	return 0, nil, nil, nil, fmt.Errorf("upstream request failed after %d retries: %w", maxRetries+1, lastErr)
@@ -55,7 +55,7 @@ func (s *Service) ProxyStream(ctx context.Context, targetURL string, referer str
 
 // handleProxyResponse processes the upstream response.
 // rewrites m3u8 playlists to proxy through our backend.
-func (s *Service) handleProxyResponse(ctx context.Context, resp *http.Response, targetURL string, referer string, rangeHeader string) (int, http.Header, []byte, io.ReadCloser, error) {
+func (s *Service) handleProxyResponse(ctx context.Context, resp *http.Response, targetURL string, referer string) (int, http.Header, []byte, io.ReadCloser, error) {
 
 	// check if response is an m3u8 playlist that needs rewriting
 	if isM3U8(targetURL, resp.Header.Get("Content-Type")) {