package auth

import (
	"errors"
	"time"

	"git.tek.govt.hu/dowerx/szoe-pontok/config"
	"git.tek.govt.hu/dowerx/szoe-pontok/database"
	"git.tek.govt.hu/dowerx/szoe-pontok/model"
	"golang.org/x/crypto/bcrypt"
	"golang.org/x/exp/rand"
)

func generateToken(length int) string {
	validRunes := []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789")
	token := make([]rune, length)
	for i := range token {
		token[i] = validRunes[rand.Intn(len(validRunes))]
	}
	return string(token)
}

func Login(user model.User) (string, error) {
	db := database.GetDB()

	rows, err := db.NamedQuery(`select "password" from "user" where "neptun" = :neptun and "email" = :email`, user)

	if err != nil {
		return "", err
	}

	if !rows.Next() {
		return "", errors.New("no such user")
	}

	var hash string
	if err = rows.Scan(&hash); err != nil {
		return "", err
	}

	if bcrypt.CompareHashAndPassword([]byte(hash), []byte(user.Password)) != nil {
		return "", errors.New("wrong password")
	}

	token := generateToken(32)

	rdb, ctx := database.GetRDB()
	result := rdb.Set(ctx, token, user.Neptun, time.Duration(config.GetConfig().API.TokenLife)*time.Second)
	if result.Err() != nil {
		return "", result.Err()
	}

	return token, nil
}