feat: added sorting and retrieving by author to chirps endpoint

main.go

@@ -289,8 +289,53 @@ func (s *server) HandleCreateUser(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
-func (s *server) HandleGetAllChirps(w http.ResponseWriter, r *http.Request) {
-	existingChirps, err := s.database.GetAllChirps(r.Context())
+const (
+	Ascending  = "asc"
+	Descending = "desc"
+)
+
+func (s *server) HandleGetChirps(w http.ResponseWriter, r *http.Request) {
+	authorId := r.URL.Query().Get("author_id")
+	sortDir := r.URL.Query().Get("sort")
+
+	hasAuthorId := strings.TrimSpace(authorId) != ""
+	hasSort := strings.TrimSpace(sortDir) != ""
+
+	validAuthorId, err := uuid.Parse(authorId)
+
+	if hasAuthorId && err != nil {
+		writeJsonResponse(w, http.StatusBadRequest, apiError{
+			Err: "Author id must be a valid uuid",
+		})
+		return
+	}
+
+	if hasSort && sortDir != Ascending && sortDir != Descending {
+		writeJsonResponse(w, http.StatusBadRequest, apiError{
+			Err: fmt.Sprintf("Sort direction must be either '%s' or '%s'", Ascending, Descending),
+		})
+		return
+	}
+
+	if !hasSort {
+		sortDir = "asc"
+	}
+
+	var existingChirps []database.Chirp
+
+	if hasAuthorId {
+		existingChirps, err = s.database.GetChirpsByAuthor(r.Context(), validAuthorId)
+	} else {
+		existingChirps, err = s.database.GetAllChirps(r.Context())
+	}
+
+	slices.SortFunc(existingChirps, func(a, b database.Chirp) int {
+		if sortDir == Descending {
+			return b.CreatedAt.Compare(a.CreatedAt)
+		}
+
+		return a.CreatedAt.Compare(b.CreatedAt)
+	})
 
 	if err != nil {
 		writeJsonResponse(w, http.StatusInternalServerError, apiError{
@@ -800,7 +845,7 @@ func main() {
 	mux.HandleFunc("PUT /api/users", server.HandleUpdateUser)
 	mux.HandleFunc("POST /api/polka/webhooks", server.HandleWebhooks)
 
-	mux.HandleFunc("GET /api/chirps", server.HandleGetAllChirps)
+	mux.HandleFunc("GET /api/chirps", server.HandleGetChirps)
 	mux.HandleFunc("GET /api/chirps/{id}", server.HandleGetChirp)
 	mux.HandleFunc("POST /api/chirps", server.HandleCreateChirp)
 	mux.HandleFunc("DELETE /api/chirps/{id}", server.HandleDeleteChirp)