package handlers

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/base64"
	"encoding/json"
	"golias/models"
	"golias/utils"
	"html/template"
	"log/slog"
	"net/http"
	"strings"
	"time"
)

func abortWithError(w http.ResponseWriter, msg string) {
	tmpl := template.Must(template.ParseGlob("components/*.html"))
	tmpl.ExecuteTemplate(w, "error", msg)
}

func HandleFrontLogin(w http.ResponseWriter, r *http.Request) {
	r.ParseForm()
	username := r.PostFormValue("username")
	if username == "" {
		msg := "username not provided"
		slog.Error(msg)
		abortWithError(w, msg)
		return
	}
	// make sure username does not exists
	cleanName := utils.RemoveSpacesFromStr(username)
	// TODO: create user in db
	// login user
	cookie, err := makeCookie(cleanName, r.RemoteAddr)
	if err != nil {
		slog.Error("failed to login", "error", err)
		abortWithError(w, err.Error())
		return
	}
	http.SetCookie(w, cookie)
	tmpl, err := template.ParseGlob("components/*.html")
	if err != nil {
		abortWithError(w, err.Error())
		return
	}
	tmpl.ExecuteTemplate(w, "main", nil)
}

func makeCookie(username string, remote string) (*http.Cookie, error) {
	// secret
	// Create a new random session token
	// sessionToken := xid.New().String()
	sessionToken := "token"
	expiresAt := time.Now().Add(time.Duration(cfg.SessionLifetime) * time.Second)
	// Set the token in the session map, along with the session information
	session := &models.Session{
		Username: username,
		Expiry:   expiresAt,
	}
	cookieName := "session_token"
	// hmac to protect cookies
	hm := hmac.New(sha256.New, []byte(cfg.CookieSecret))
	hm.Write([]byte(cookieName))
	hm.Write([]byte(sessionToken))
	signature := hm.Sum(nil)
	// b64 enc to avoid non-ascii
	cookieValue := base64.URLEncoding.EncodeToString([]byte(
		string(signature) + sessionToken))
	cookie := &http.Cookie{
		Name:     cookieName,
		Value:    cookieValue,
		Secure:   true,
		HttpOnly: true,
		SameSite: http.SameSiteNoneMode,
		Domain:   cfg.ServerConfig.Host,
	}
	slog.Info("check remote addr for cookie set",
		"remote", remote, "session", session)
	if strings.Contains(remote, "192.168.0") {
		// no idea what is going on
		// cookie.Domain = "192.168.0.15"
		cookie.Domain = "home.host"
		slog.Info("changing cookie domain", "domain", cookie.Domain)
	}
	// set ctx?
	// set user in session
	if err := cacheSetSession(sessionToken, session); err != nil {
		return nil, err
	}
	return cookie, nil
}

func cacheGetSession(key string) (*models.Session, error) {
	userSessionB, err := memcache.Get(key)
	if err != nil {
		return nil, err
	}
	var us *models.Session
	if err := json.Unmarshal(userSessionB, &us); err != nil {
		return nil, err
	}
	return us, nil
}

func cacheSetSession(key string, session *models.Session) error {
	sesb, err := json.Marshal(session)
	if err != nil {
		return err
	}
	memcache.Set(key, sesb)
	// expire in 10 min
	memcache.Expire(key, 10*60)
	return nil
}