package main

import (
	"fmt"
	"log"
	"net/http"
	"time"

	"golang.org/x/crypto/bcrypt"
)

func getUserAndToken(tokenBody string) (User, Token, error) {
	var t Token
	var u User

	err := db.Where("body = ?", tokenBody).First(&t).Error
	if err != nil {
		return User{}, Token{}, fmt.Errorf("error when fetching token: %w", err)
	}

	err = db.Where("id = ?", t.UserID).First(&u).Error
	if err != nil {
		return User{}, Token{}, fmt.Errorf("error when fetching user: %w", err)
	}

	return u, t, nil
}

func logoutUser(w http.ResponseWriter, r *http.Request) {
	cookie, err := r.Cookie("wasmcloud-token")
	if err != nil {
		http.Redirect(w, r, "/login", http.StatusSeeOther)
		return
	}

	u, t, err := getUserAndToken(cookie.Value)
	if err != nil {
		http.Error(w, "unknown authentication token", http.StatusBadRequest)
		return
	}

	err = db.Delete(&t).Error
	if err != nil {
		log.Printf("can't delete token %d for %s: %v", t.ID, u.Username, err)
		http.Error(w, "internal server error, please contact support", http.StatusInternalServerError)
		return
	}

	http.SetCookie(w, &http.Cookie{Name: "wasmcloud-token", MaxAge: -1, Expires: time.Now().Add(-500 * time.Hour)})
	log.Printf("logout for %s", u.Username)
	http.Redirect(w, r, "/login", http.StatusSeeOther)
}

func loginUser(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		showLoginForm(w, r)
		return
	}

	r.ParseMultipartForm(1024)
	defer r.Body.Close()

	for _, val := range []string{"username", "password"} {
		if r.FormValue(val) == "" {
			http.Error(w, "missing form data "+val, http.StatusBadRequest)
			return
		}
	}

	uname := r.FormValue("username")
	pw := r.FormValue("password")

	var u User
	err := db.Where("username = ?", uname).First(&u).Error
	if err != nil {
		log.Printf("can't lookup user %s: %v", uname, err)
		http.Error(w, "unknown user/password", http.StatusBadRequest)
		return
	}

	err = bcrypt.CompareHashAndPassword(u.CryptedPassword, []byte(pw))
	if err != nil {
		log.Printf("wrong password for %s: %v", uname, err)
		http.Error(w, "unknown user/password", http.StatusBadRequest)
		return
	}

	t, err := makeToken(u)
	if err != nil {
		log.Printf("can't make token: %v", err)
		http.Error(w, "internal server error, contact support", http.StatusInternalServerError)
		return
	}

	log.Printf("login for %s", u.Username)
	http.SetCookie(w, t.ToCookie())
	http.Redirect(w, r, "/control/", http.StatusSeeOther)
}

func registerUser(w http.ResponseWriter, r *http.Request) {
	if r.Method == "GET" {
		showRegisterForm(w, r)
		return
	}

	r.ParseMultipartForm(1024)
	defer r.Body.Close()

	for _, val := range []string{"username", "password", "email"} {
		if r.FormValue(val) == "" {
			http.Error(w, "missing form data "+val, http.StatusBadRequest)
			return
		}
	}

	cryptPW, err := bcrypt.GenerateFromPassword([]byte(r.FormValue("password")), bcrypt.DefaultCost)
	if err != nil {
		panic(err)
	}

	u := User{
		Username:        r.FormValue("username"),
		CryptedPassword: cryptPW,
		Email:           r.FormValue("email"),
	}

	err = db.Save(&u).Error
	if err != nil {
		log.Printf("can't save user: %v", err)
		http.Error(w, "can't save new user", http.StatusInternalServerError)
		return
	}

	tok, err := makeToken(u)
	if err != nil {
		log.Printf("can't make token: %v", err)
		http.Error(w, "internal server error, contact support", http.StatusInternalServerError)
		return
	}

	log.Printf("created user %s", u.Username)
	http.SetCookie(w, tok.ToCookie())
	http.Redirect(w, r, "/control/", http.StatusSeeOther)
}