feat: SEO backend output (2/4)

api/handlers/site/sitemapHandler.go

@@ -0,0 +1,87 @@
+package site
+
+import (
+	"RenewCMS/api/pkg/apperr"
+	validator "RenewCMS/api/pkg/validator"
+	"RenewCMS/internal/infrastructure/useCases"
+	"encoding/json"
+	"log"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+
+	"github.com/go-chi/chi/v5"
+)
+
+const (
+	defaultSitemapPage = 1
+	defaultSitemapSize = 100
+	totalCountHeader   = "X-Total-Count"
+)
+
+type SitemapHandler struct {
+	ListUseCase *useCases.ListSitemapUseCase
+}
+
+func NewSitemapHandler(list *useCases.ListSitemapUseCase) *SitemapHandler {
+	return &SitemapHandler{ListUseCase: list}
+}
+
+type sitemapQuery struct {
+	Page int `validate:"gte=1"`
+	Size int `validate:"oneof=25 50 100 500"`
+}
+
+type sitemapItem struct {
+	URL        string `json:"url"`
+	ModifiedAt string `json:"modified_at"`
+	Noindex    bool   `json:"noindex"`
+}
+
+func sitemapIntParam(values url.Values, name string, fallback int) (int, error) {
+	if !values.Has(name) {
+		return fallback, nil
+	}
+	return strconv.Atoi(values.Get(name))
+}
+
+func readSitemapQuery(values url.Values) (sitemapQuery, error) {
+	page, err := sitemapIntParam(values, "page", defaultSitemapPage)
+	if err != nil {
+		return sitemapQuery{}, err
+	}
+	size, err := sitemapIntParam(values, "size", defaultSitemapSize)
+	if err != nil {
+		return sitemapQuery{}, err
+	}
+	return sitemapQuery{Page: page, Size: size}, nil
+}
+
+func (h *SitemapHandler) Sitemap(w http.ResponseWriter, r *http.Request) {
+	query, err := readSitemapQuery(r.URL.Query())
+	if err != nil || validator.Validate.Struct(query) != nil {
+		http.Error(w, apperr.BodyErrorMessage, http.StatusBadRequest)
+		return
+	}
+
+	page, err := h.ListUseCase.List(chi.URLParam(r, "key"), query.Page, query.Size)
+	if err != nil {
+		writeSiteError(w, err)
+		return
+	}
+
+	items := make([]sitemapItem, 0, len(page.Entries))
+	for _, entry := range page.Entries {
+		items = append(items, sitemapItem{URL: entry.URL, ModifiedAt: entry.ModifiedAt.UTC().Format(time.RFC3339), Noindex: entry.Noindex})
+	}
+	body, err := json.Marshal(items)
+	if err != nil {
+		http.Error(w, "Failed to encode response", http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set(totalCountHeader, strconv.Itoa(page.Total))
+	if _, err := w.Write(body); err != nil {
+		log.Printf("Failed to write response: %v", err)
+	}
+}