use host matching instead of regex (desc)

why? using regex on every single message the bot receives, even simple patterns, can be very harmful for your cpu lol

ext/util.go

@@ -3,65 +3,102 @@ package ext
 import (
 	"fmt"
 	"govd/models"
+	"net/url"
+	"strings"
+	"sync"
 )
 
-var maxRedirects = 5
+var (
+	maxRedirects = 5
 
-func CtxByURL(url string) (*models.DownloadContext, error) {
-	var redirectCount int
+	extractorsByHost map[string][]*models.Extractor
+	extractorMapOnce sync.Once
+)
 
-	currentURL := url
-
-	for redirectCount <= maxRedirects {
+func initExtractorMap() {
+	extractorMapOnce.Do(func() {
+		extractorsByHost = make(map[string][]*models.Extractor)
 		for _, extractor := range List {
-			matches := extractor.URLPattern.FindStringSubmatch(currentURL)
-			if matches == nil {
-				continue
-			}
-
-			groupNames := extractor.URLPattern.SubexpNames()
-			if len(matches) == 0 {
-				continue
-			}
-
-			groups := make(map[string]string)
-			for i, name := range groupNames {
-				if name != "" {
-					groups[name] = matches[i]
+			if len(extractor.Host) > 0 {
+				for _, domain := range extractor.Host {
+					extractorsByHost[domain] = append(extractorsByHost[domain], extractor)
 				}
 			}
-			groups["match"] = matches[0]
-
-			ctx := &models.DownloadContext{
-				MatchedContentID:  groups["id"],
-				MatchedContentURL: groups["match"],
-				MatchedGroups:     groups,
-				Extractor:         extractor,
-			}
-
-			if !extractor.IsRedirect {
-				return ctx, nil
-			}
-
-			response, err := extractor.Run(ctx)
-			if err != nil {
-				return nil, err
-			}
-			if response.URL == "" {
-				return nil, fmt.Errorf("no URL found in response")
-			}
-
-			currentURL = response.URL
-			redirectCount++
-
-			break
 		}
+	})
+}
+
+func CtxByURL(urlStr string) (*models.DownloadContext, error) {
+	initExtractorMap()
+
+	var redirectCount int
+	currentURL := urlStr
+
+	for redirectCount <= maxRedirects {
+		parsedURL, err := url.Parse(currentURL)
+		if err != nil {
+			return nil, fmt.Errorf("invalid URL: %v", err)
+		}
+
+		host := strings.TrimPrefix(parsedURL.Host, "www.")
+
+		extractors := extractorsByHost[host]
+		if len(extractors) == 0 {
+			return nil, nil
+		}
+
+		var extractor *models.Extractor
+		var matches []string
+		var groups map[string]string
+
+		for _, ext := range extractors {
+			matches = ext.URLPattern.FindStringSubmatch(currentURL)
+			if matches != nil {
+				extractor = ext
+				groupNames := ext.URLPattern.SubexpNames()
+				groups = make(map[string]string)
+				for i, name := range groupNames {
+					if name != "" && i < len(matches) {
+						groups[name] = matches[i]
+					}
+				}
+				groups["match"] = matches[0]
+				break
+			}
+		}
+
+		if extractor == nil || matches == nil {
+			return nil, nil
+		}
+
+		ctx := &models.DownloadContext{
+			MatchedContentID:  groups["id"],
+			MatchedContentURL: groups["match"],
+			MatchedGroups:     groups,
+			Extractor:         extractor,
+		}
+
+		if !extractor.IsRedirect {
+			return ctx, nil
+		}
+
+		response, err := extractor.Run(ctx)
+		if err != nil {
+			return nil, err
+		}
+		if response.URL == "" {
+			return nil, fmt.Errorf("no URL found in response")
+		}
+
+		currentURL = response.URL
+		redirectCount++
 
 		if redirectCount > maxRedirects {
 			return nil, fmt.Errorf("exceeded maximum number of redirects (%d)", maxRedirects)
 		}
 	}
-	return nil, nil
+
+	return nil, fmt.Errorf("failed to extract from URL: %s", urlStr)
 }
 
 func ByCodeName(codeName string) *models.Extractor {