package db

import (
	"context"
	"database/sql"
	_ "embed"
	"time"

	_ "github.com/go-sql-driver/mysql"
	"golang.org/x/crypto/bcrypt"
)

//go:embed setup.sql
var setupSql string

const DB_NAME = "s3Browser"

type mysqlDB struct {
	dbConn *sql.DB
}

func NewDB(dataSourceName string) (DB, error) {
	db, err := sql.Open("mysql", dataSourceName)

	if err != nil {
		return nil, err
	}

	db.SetConnMaxLifetime(time.Minute * 3)
	db.SetMaxOpenConns(10)
	db.SetMaxIdleConns(10)

	return &mysqlDB{
		dbConn: db,
	}, nil
}

func (d *mysqlDB) Setup() error {
	tx, err := d.dbConn.Begin()
	if err != nil {
		return err
	}

	_, err = tx.Exec(setupSql)
	if err != nil {
		tx.Rollback()
		return err
	}

	err = tx.Commit()
	if err != nil {
		return err
	}

	return nil
}

func (d *mysqlDB) CheckLogin(ctx context.Context, username, password string) (bool, error) {
	rows, err := d.dbConn.QueryContext(ctx, "SELECT password FROM user WHERE username = ?", username)
	if err != nil {
		return false, err
	}

	if !rows.Next() {
		return false, nil
	}

	var passwordHash []byte
	err = rows.Scan(&passwordHash)
	if err != nil {
		return false, err
	}

	if bcrypt.CompareHashAndPassword(passwordHash, []byte(password)) != nil {
		return false, nil
	}

	return true, nil
}

func (d *mysqlDB) AddUser(ctx context.Context, username, password string) error {
	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return err
	}

	_, err = d.dbConn.ExecContext(ctx, "INSERT INTO user (username,password) VALUES (?,?)", username, hash)

	if err != nil {
		return err
	}

	return nil
}