package web

import (
	"bytes"
	"errors"
	"net/http"

	"github.com/google/uuid"
	"github.com/gramanas/blogspace/internal/store"
)

// handleMedia serves an uploaded image. Ids are immutable, so clients may cache forever.
func (s *Server) handleMedia(w http.ResponseWriter, r *http.Request) {
	id, err := uuid.Parse(r.PathValue("id"))
	if err != nil {
		http.NotFound(w, r)
		return
	}
	etag := `"` + id.String() + `"`
	if r.Header.Get("If-None-Match") == etag {
		w.WriteHeader(http.StatusNotModified)
		return
	}
	img, err := s.st.ImageData(r.Context(), id)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			http.NotFound(w, r)
			return
		}
		s.serverError(w, err)
		return
	}
	w.Header().Set("Content-Type", img.ContentType)
	w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
	w.Header().Set("ETag", etag)
	w.Header().Set("X-Content-Type-Options", "nosniff")
	http.ServeContent(w, r, img.Filename, img.CreatedAt, bytes.NewReader(img.Data))
}