package twilio

import (
	"context"
	"kas/cps"
	"log"
	"net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		log.Printf("twilio receive hook: received %s request; only %s requests are supported",
			r.Method, http.MethodPost)
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	err := r.ParseForm()
	if err != nil {
		log.Printf("twilio receive hook: couldn't parse form contents: %s", err)
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	message, err := MessageFromValues(r.Form)
	if err != nil {
		log.Printf("twilio receive hook: received an invalid message: %s", err)
		http.Error(w, "invalid request", http.StatusBadRequest)
		return
	}

	if !config.NumberAuthorized(message.Source) {
		log.Printf("twilio receive hook: received message from unknown sender %v", message)
		http.Error(w, "not authorized", http.StatusUnauthorized)
		return
	}

	w.Write([]byte("accepted"))

	response, err := cps.Handle(context.Background(), message.Body)
	if err != nil {
		log.Printf("twilio receive hook: %s", err)
	}

	err = Send(message.Source, response.String())
	if err != nil {
		log.Printf("twilio receive hook: %s", err)
	}
}

func Start() error {
	http.AddRoute("/twilio", handler)
}