func redirectHandler(db database.DB) http.Handler {
handler := func(w http.ResponseWriter, r *http.Request) {
if r.Method != "GET" {
http.Error(w, "GET only", http.StatusMethodNotAllowed)
return
}
shorturl := r.URL.Path[len(redirectPath):]
if shorturl == "" { // display usage
usage, err := ioutil.ReadFile("usage.html")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
writeLogErr(w, usage)
return
}
url, err := db.Decode(shorturl)
if err, ok := err.(database.ErrNotFound); ok {
http.Error(w, err.Error(), http.StatusNotFound)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
http.Redirect(w, r, string(url), 301)
}
return http.HandlerFunc(handler)
}
func decodeHandler(db database.DB) http.Handler {
handler := func(w http.ResponseWriter, r *http.Request) {
if r.Method != "GET" {
http.Error(w, "use GET to decode urls", http.StatusMethodNotAllowed)
return
}
shorturl := r.URL.Path[len(decodePath):]
url, err := db.Decode(shorturl)
if err, ok := err.(database.ErrNotFound); ok {
http.Error(w, err.Error(), http.StatusNotFound)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
writeLogErr(w, []byte(url))
}
return http.HandlerFunc(handler)
}