package mysql

import (
	"context"
	"database/sql"
	"fmt"
	"time"

	// registers the MySQL driver with database/sql
	_ "github.com/go-sql-driver/mysql"
)

type DB struct {
	sql *sql.DB
}

func Open(dsn string) (*DB, error) {
	if dsn == "" {
		return &DB{}, nil
	}
	sqlDB, err := sql.Open("mysql", dsn)
	if err != nil {
		return nil, fmt.Errorf("mysql open: %w", err)
	}
	sqlDB.SetMaxOpenConns(64)
	sqlDB.SetConnMaxLifetime(30 * time.Minute)
	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()
	if err := sqlDB.PingContext(ctx); err != nil {
		_ = sqlDB.Close()
		return nil, fmt.Errorf("mysql ping: %w", err)
	}
	return &DB{sql: sqlDB}, nil
}

func (d *DB) SQL() *sql.DB { return d.sql }

func (d *DB) Close() error {
	if d == nil || d.sql == nil {
		return nil
	}
	return d.sql.Close()
}

func (d *DB) Ready() bool { return d != nil && d.sql != nil }