package db

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

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

func Open(dsn string) (*sql.DB, error) {
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		return nil, fmt.Errorf("open db: %w", err)
	}
	if err := db.Ping(); err != nil {
		return nil, fmt.Errorf("ping db: %w", err)
	}
	return db, nil
}

func Migrate(ctx context.Context, db *sql.DB) error {
	for _, stmt := range statements {
		if _, err := db.ExecContext(ctx, stmt); err != nil {
			var mysqlErr *mysql.MySQLError
			if errors.As(err, &mysqlErr) && mysqlErr.Number == 1060 {
				continue // duplicate column — already exists
			}
			return fmt.Errorf("migrate: %w", err)
		}
	}
	return nil
}