package controller

import (
	"crypto/rand"
	"encoding/base64"
	"errors"

	"git.tek.govt.hu/dowerx/chat/server/dao"
	"git.tek.govt.hu/dowerx/chat/server/model"
	"golang.org/x/crypto/bcrypt"
)

type AuthController struct {
	userDAO    dao.IUserDAO
	sessionDAO dao.ISessionDAO
}

const (
	MIN_USERNAME_LENGTH int = 3
	MIN_PASSWORD_LENGTH int = 6
	HASH_COST           int = bcrypt.DefaultCost
	TOKEN_LENGTH        int = 32
)

func (c *AuthController) init() error {
	userDAO, err := dao.MakeUserDAO()
	c.userDAO = userDAO
	if err != nil {
		return err
	}

	sessionDao, err := dao.MakeSessionDAO()
	c.sessionDAO = sessionDao
	if err != nil {
		return err
	}

	return nil
}

func (c AuthController) Register(username string, password string, repeatPassword string) error {
	if len(username) < MIN_USERNAME_LENGTH {
		return errors.New("username too short")
	}
	if len(password) < MIN_PASSWORD_LENGTH {
		return errors.New("password too short")
	}

	if password != repeatPassword {
		return errors.New("passwords don't match")
	}

	hash, err := bcrypt.GenerateFromPassword([]byte(password), HASH_COST)

	if err != nil {
		return err
	}

	return c.userDAO.Create(model.User{
		Username:     username,
		PasswordHash: string(hash),
	})
}

func generateToken(length int) (string, error) {
	b := make([]byte, length)
	_, err := rand.Read(b)
	if err != nil {
		return "", err
	}

	return base64.URLEncoding.EncodeToString(b), nil
}

func (c AuthController) Login(username string, password string) (string, bool, error) {
	user, err := c.userDAO.Read(model.User{Username: username})
	if err != nil {
		return "", false, err
	}

	if err := bcrypt.CompareHashAndPassword([]byte(user.PasswordHash), []byte(password)); err != nil {
		return "", false, errors.New("wrong password")
	}

	token, err := generateToken(TOKEN_LENGTH)
	if err != nil {
		return "", false, err
	}

	err = c.sessionDAO.Set(token, user.ID)
	if err != nil {
		return "", false, err
	}

	return token, true, nil
}

func (c AuthController) Logout(token string) error {
	return c.sessionDAO.Delete(token)
}