package gziphttp

import (
	"fmt"
	"net/http"
	"path"
	"strings"
)

func SetContentTypeIfMedia(w http.ResponseWriter, r *http.Request) {
	ext := strings.ToLower(path.Ext(r.URL.Path))
	if i := strings.LastIndex(ext, "."); i != -1 {
		ext = ext[i:]
	}
	k := "Content-Type"
	v := ""
	switch ext {
	case ".mp4":
		v = "video/mp4"
	case ".mkv":
		v = "video/x-matroska"
	case ".mp3":
		v = "audio/mpeg3"
	case ".epub", ".mobi":
		k = "Content-Disposition"
		v = "attachment"
	case ".jpg", ".jpeg":
		v = "image/jpeg"
	case ".md":
		v = "text/markdown"
		v = "text/html"
	case ".gif":
		v = "image/gif"
	case ".png":
		v = "image/png"
	case ".ico":
		v = "image/x-icon"
	case ".svg":
		v = "image/svg+xml"
	case ".css":
		v = "text/css"
	case ".js":
		v = "text/javascript"
	case ".json":
		v = "application/json"
	case ".html", ".htm":
		v = "text/html"
	case ".pdf":
		w.Header().Set("Content-Disposition", fmt.Sprintf("inline; filename=%q", path.Base(r.URL.Path)))
		v = "application/pdf"
	case ".webm":
		v = "video/webm"
	case ".weba":
		v = "audio/webm"
	case ".webp":
		v = "image/webp"
	case ".zip":
		v = "application/zip"
	case ".7z":
		v = "application/x-7z-compressed"
	case ".tar":
		v = "application/x-tar"
	case ".m4b":
		v = "application/octet-stream"
	case ".xml", ".rss", ".feed", ".rdf":
		v = "application/rss+xml"
	default:
		return
	}
	w.Header().Set(k, v)
}