package banco

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

	_ "github.com/go-sql-driver/mysql"
)

func Abrir(dsn string, maxConns int) (*sql.DB, error) {
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		return nil, err
	}
	if maxConns < 8 {
		maxConns = 8
	}
	db.SetMaxOpenConns(maxConns)
	idle := maxConns / 2
	if idle < 4 {
		idle = 4
	}
	db.SetMaxIdleConns(idle)
	db.SetConnMaxLifetime(30 * time.Minute)
	if err := db.Ping(); err != nil {
		_ = db.Close()
		return nil, fmt.Errorf("ping MySQL: %w", err)
	}
	return db, nil
}

func Fechar(db *sql.DB) {
	if db != nil {
		_ = db.Close()
	}
}