package migrate

import (
	"fmt"
	"strings"
)

func fetchColumns(sql string) ([]string, error) {
	if !strings.HasPrefix(sql, "CREATE TABLE ") {
		return []string{}, fmt.Errorf("Sql input is not a DDL statement.")
	}

	parenIdx := strings.Index(sql, "(")
	return strings.Split(sql[parenIdx+1:len(sql)-1], ","), nil
}

func selectName(columns []string) []string {
	var results []string
	for _, column := range columns {
		col := strings.SplitN(strings.Trim(column, " \n\t"), " ", 2)
		results = append(results, col[0])
	}
	return results
}

func setForUpdate(left []string, right []string) string {
	var results []string
	for k, str := range left {
		results = append(results, fmt.Sprintf("%s = %s", str, right[k]))
	}
	return strings.Join(results, ", ")
}