package main

import (
	"database/sql"
	"fmt"

	_ "github.com/mattn/go-sqlite3"
	"golang.org/x/crypto/bcrypt"
)

const (
	bcryptCost = 12
)

func Register(tx *sql.Tx, username, password string) error {
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcryptCost)
	if err != nil {
		return err
	}

	_, err = tx.Exec(
		`INSERT INTO users (username, password_bcrypt) VALUES(?, ?);`,
		username,
		hash,
	)

	return err
}

func Authenticate(tx *sql.Tx, username, password string) error {
	var hash []byte

	row := tx.QueryRow(
		`SELECT password_bcrypt from users WHERE username=?;`,
		username,
	)

	err := row.Scan(&hash)
	if err != nil {
		return fmt.Errorf("Failed to get password hash from database: %w", err)
	}

	return bcrypt.CompareHashAndPassword(hash, []byte(password))
}