feat: add Kemono parser with download info extraction and API handling

parsers/kemono/download.go

@@ -0,0 +1,36 @@
+package kemono
+
+import (
+	"net/url"
+	"strings"
+)
+
+type DownloadInfo struct {
+	ServiceName string
+	UserID      string
+	PostID      string
+}
+
+func extractDownloadInfoFromURL(u string) *DownloadInfo {
+	if !strings.HasPrefix(u, "http://") && !strings.HasPrefix(u, "https://") {
+		u = "https://" + u
+	}
+	url, err := url.Parse(u)
+	if err != nil {
+		return nil
+	}
+	parts := strings.Split(strings.Trim(url.Path, "/"), "/")
+	if len(parts) == 3 {
+		return &DownloadInfo{
+			ServiceName: parts[0],
+			UserID:      parts[2],
+		}
+	} else if len(parts) == 5 && parts[3] == "post" {
+		return &DownloadInfo{
+			ServiceName: parts[0],
+			UserID:      parts[2],
+			PostID:      parts[4],
+		}
+	}
+	return nil
+}