feat: tag system

internal/web/handler.go

@@ -6,6 +6,7 @@ import (
 	"donniemarko/internal/service"
 	"html/template"
 	"net/http"
+	"net/url"
 	"strings"
 )
 
@@ -34,6 +35,10 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	// Handle individual notes
 	if strings.HasPrefix(path, "/notes/") {
+		if strings.Contains(path, "/tags") {
+			h.handleTags(w, r)
+			return
+		}
 		h.handleNotes(w, r)
 		return
 	}
@@ -160,3 +165,61 @@ func (h *Handler) handleNotes(w http.ResponseWriter, r *http.Request) {
 
 	h.templates.Render(w, "index", state)
 }
+
+func (h *Handler) handleTags(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	noteID, tag, isRemove := parseTagRoute(r.URL.Path)
+	if noteID == "" {
+		http.NotFound(w, r)
+		return
+	}
+
+	if isRemove {
+		if tag == "" {
+			http.Error(w, "Missing tag", http.StatusBadRequest)
+			return
+		}
+		if err := h.notesService.RemoveTag(noteID, tag); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	} else {
+		if err := r.ParseForm(); err != nil {
+			http.Error(w, "Invalid form", http.StatusBadRequest)
+			return
+		}
+		tag := r.FormValue("tag")
+		if tag == "" {
+			http.Error(w, "Missing tag", http.StatusBadRequest)
+			return
+		}
+		if err := h.notesService.AddTag(noteID, tag); err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+	}
+
+	http.Redirect(w, r, "/notes/"+noteID, http.StatusSeeOther)
+}
+
+func parseTagRoute(path string) (noteID string, tag string, isRemove bool) {
+	parts := strings.Split(strings.Trim(path, "/"), "/")
+	if len(parts) < 3 || parts[0] != "notes" || parts[2] != "tags" {
+		return "", "", false
+	}
+
+	noteID = parts[1]
+	if len(parts) >= 4 {
+		decoded, err := url.PathUnescape(parts[3])
+		if err != nil {
+			return noteID, "", true
+		}
+		return noteID, decoded, true
+	}
+
+	return noteID, "", false
+}