package auth

import (
	"fmt"

	"github.com/aziis98/lupus-lite/database"
	"github.com/aziis98/lupus-lite/model"
	"github.com/aziis98/lupus-lite/util"
	"golang.org/x/crypto/bcrypt"
)

type memAuth struct {
	db database.Database

	sessions map[string]string
}

func (auth *memAuth) Register(username, password string) error {
	passwordBCrypt, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return err
	}

	return auth.db.CreateUser(model.User{
		Username:       username,
		PasswordBCrypt: passwordBCrypt,
	})
}

func (auth *memAuth) Login(username, password string) (string, error) {
	user, err := auth.db.GetUser(username)
	if err != nil {
		return "", err
	}

	if err := bcrypt.CompareHashAndPassword(user.PasswordBCrypt, []byte(password)); err != nil {
		return "", err
	}

	token := util.GenerateRandomString(16)
	auth.sessions[token] = username

	return token, nil
}

func (auth *memAuth) UserForSession(token string) (string, error) {
	username, ok := auth.sessions[token]
	if !ok {
		return "", fmt.Errorf(`invalid session token`)
	}

	return username, nil
}

func (auth *memAuth) GetUser(username string) (model.User, error) {
	return auth.db.GetUser(username)
}