package webapi

import (
	"errors"
	"fmt"
	"log"
	"net"
	"net/http"
	"net/url"

	"gitea.nehmer.net/torben/dyndns/service"
)

func init() {
	router.HandleFunc("/update", handleUpdate)
}

func handleUpdate(w http.ResponseWriter, r *http.Request) {
	err := r.ParseForm()
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	ur, err := createUpdateRequestFromForm(r.Form)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	uc, err := service.LoadConfigForUser(ur.UserName, ur.Password)
	if err != nil {
		if _, ok := err.(*service.UnauthorizedError); ok {
			http.Error(w, err.Error(), http.StatusUnauthorized)
		} else {
			http.Error(w, err.Error(), http.StatusInternalServerError)
		}
		log.Printf("Authorization failed: %v", err)
		return
	}

	ur.Config = uc

	// Start DEBUG Output
	log.Println("Final request")
	log.Println(ur.PrettyPrint())
	for _, other := range uc.Others {
		log.Printf("Other %s, IID %v, merged: %v",
			other.Hostname, other.V6IID, other.ConvertIIDToAddress(ur.IPv6Net))
	}

	log.Println("WebAPI Config:")
	log.Println(C.PrettyPrint())
	log.Println("Service Config:")
	log.Println(service.C.PrettyPrint())
	// End DEBUG Output

	if err := ur.Process(); err != nil {
		log.Printf("failed to process UpdateRequest: %v", err)
		http.Error(w, err.Error(), http.StatusInternalServerError)
	}

	w.Header().Set("Content-Type", "text/plain")
	fmt.Fprintln(w, "OK")
}

func createUpdateRequestFromForm(form url.Values) (*service.UpdateRequest, error) {
	ur := &service.UpdateRequest{}

	if form.Get("IPv4") != "" {
		if ur.IPv4 = net.ParseIP(form.Get("IPv4")); ur.IPv4 == nil {
			return nil, errors.New("could not parse IPv4 address")
		}
	}

	if form.Get("IPv6") != "" {
		if ur.IPv6 = net.ParseIP(form.Get("IPv6")); ur.IPv6 == nil {
			return nil, errors.New("could not parse IPv6 address")
		}
	}

	ur.UserName = form.Get("UserName")
	if ur.UserName == "" {
		return nil, errors.New("a UserName must be specified")
	}

	ur.Password = form.Get("Password")
	if ur.Password == "" {
		return nil, errors.New("a Password must be specified")
	}

	if ip6net := form.Get("IPv6Net"); ip6net != "" {
		_, ipnet, err := net.ParseCIDR(ip6net)
		if err != nil {
			return nil, errors.New("could not parse IPv6Net")
		}
		ur.IPv6Net = ipnet
	}

	return ur, nil
}