package web

import (
	"errors"
	"io/fs"
	"net/http"

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

// handleMedia serves an uploaded file. Ids are immutable, so clients may cache
// forever (a renamed file keeps its old download name in caches; acceptable).
// What may render inline is decided by servedAs, see filetype.go.
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
	}
	f, err := blogStore(r).FileMeta(r.Context(), id)
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			http.NotFound(w, r)
			return
		}
		s.serverError(w, err)
		return
	}
	ctype, disposition := servedAs(f.ContentType, r.URL.Query().Has("download"))
	w.Header().Set("Content-Type", ctype)
	w.Header().Set("Content-Disposition", contentDisposition(disposition, f.Filename))
	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, f.Filename, f.CreatedAt, blogStore(r).FileReader(r.Context(), f))
}

// handleFavicon answers the browsers that ask for /favicon.ico regardless of
// the <link rel="icon"> tags: the blog's own icon if it set one, else the
// Blogspace default. Without this the request would render the 404 page.
func (s *Server) handleFavicon(w http.ResponseWriter, r *http.Request) {
	if icon := ParseTheme(currentBlog(r).ThemeJSON).Favicon; icon != "" {
		http.Redirect(w, r, "/media/"+icon, http.StatusFound)
		return
	}
	data, err := fs.ReadFile(s.tpl.AssetsFS(), "favicon.png")
	if err != nil {
		s.serverError(w, err)
		return
	}
	w.Header().Set("Content-Type", "image/png")
	if !s.cfg.Dev {
		w.Header().Set("Cache-Control", "public, max-age=3600")
	}
	w.Write(data)
}