package db

import (
	"fmt"
	"strconv"
	"strings"
)

func validateData(table string, keyField string, data map[string]any) (any, error) {
	if table == "" {
		return nil, fmt.Errorf("表名不能为空")
	}

	if len(data) == 0 {
		return nil, fmt.Errorf("数据不能为空")
	}

	if keyField == "" {
		return nil, fmt.Errorf("主键字段不能为空")
	}

	val, ok := data[keyField]
	if !ok {
		return nil, fmt.Errorf("缺少主键字段: %s", keyField)
	}

	if val == nil {
		return nil, fmt.Errorf("主键字段值不能为空")
	}

	return val, nil
}

// 高效 placeholder 转换
func convertPlaceholder(sql string) string {
	var sb strings.Builder
	sb.Grow(len(sql))

	argIndex := 1

	for i := 0; i < len(sql); i++ {
		if sql[i] == '?' {
			sb.WriteByte('$')
			sb.WriteString(strconv.Itoa(argIndex))
			argIndex++
		} else {
			sb.WriteByte(sql[i])
		}
	}

	return sb.String()
}