package static

import (
	"io"
	"net/http"
	"strings"

	"haixun-backend/internal/library/storage"
)

func PublicAssetHandler(reader storage.ObjectReader) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if reader == nil {
			http.Error(w, "asset storage is not configured", http.StatusServiceUnavailable)
			return
		}
		key := strings.TrimSpace(r.URL.Query().Get("key"))
		if key == "" {
			http.Error(w, "missing asset key", http.StatusBadRequest)
			return
		}
		if !storage.IsPublicAssetKey(key) {
			http.Error(w, "asset not found", http.StatusNotFound)
			return
		}

		if strings.HasPrefix(key, storage.EphemeralKeyPrefix) {
			data, contentType, ok := storage.DefaultEphemeralAssetStore().Get(key)
			if !ok {
				http.Error(w, "asset not found", http.StatusNotFound)
				return
			}
			w.Header().Set("Content-Type", contentType)
			w.Header().Set("Cache-Control", "no-store")
			_, _ = w.Write(data)
			return
		}

		body, contentType, err := reader.GetObject(r.Context(), key)
		if err != nil {
			http.Error(w, "asset not found", http.StatusNotFound)
			return
		}
		defer body.Close()

		w.Header().Set("Content-Type", contentType)
		w.Header().Set("Cache-Control", "public, max-age=3600")
		_, _ = io.Copy(w, body)
	}
}