func iconHandler(w http.ResponseWriter, r *http.Request) {
url := r.FormValue("url")
if len(url) == 0 {
writeAPIError(w, 400, errors.New("need url parameter"), true)
return
}
size := r.FormValue("size")
if size == "" {
writeAPIError(w, 400, errors.New("need size parameter"), true)
return
}
minSize, err := strconv.Atoi(size)
if err != nil || minSize < 0 || minSize > 500 {
writeAPIError(w, 400, errors.New("bad size parameter"), true)
return
}
finder := besticon.IconFinder{}
formats := r.FormValue("formats")
if formats != "" {
finder.FormatsAllowed = strings.Split(r.FormValue("formats"), ",")
}
err, _ = finder.FetchIcons(url)
if err != nil {
writeAPIError(w, 404, err, true)
return
}
icon := finder.IconWithMinSize(minSize)
if icon != nil {
http.Redirect(w, r, icon.URL, 302)
return
}
fallbackIconURL := r.FormValue("fallback_icon_url")
if fallbackIconURL != "" {
http.Redirect(w, r, fallbackIconURL, 302)
return
}
iconColor := finder.MainColorForIcons()
letter := lettericon.MainLetterFromURL(url)
redirectPath := lettericon.IconPath(letter, size, iconColor)
http.Redirect(w, r, redirectPath, 302)
}
