package employeecollection

import (
	"strings"

	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

// NormalizePaymentVouchers 校验并规范化支付凭证对象键列表。
// 规则：数量必须在 1 至 5 个之间、每个键去空格后非空且不超过长度上限、不允许重复。
// 只接受对象存储键引用，不接受内联内容，避免敏感付款材料进入业务事实。
func NormalizePaymentVouchers(keys []string) ([]string, error) {
	if len(keys) < constants.EmployeeCollectionVoucherMinCount ||
		len(keys) > constants.EmployeeCollectionVoucherMaxCount {
		return nil, errors.New(errors.CodeEmployeeCollectionVoucherInvalid)
	}
	normalized := make([]string, 0, len(keys))
	seen := make(map[string]struct{}, len(keys))
	for _, key := range keys {
		trimmed := strings.TrimSpace(key)
		if trimmed == "" {
			return nil, errors.New(errors.CodeEmployeeCollectionVoucherInvalid)
		}
		if len([]rune(trimmed)) > constants.EmployeeCollectionVoucherKeyMaxLength {
			return nil, errors.New(errors.CodeEmployeeCollectionVoucherInvalid)
		}
		if _, exists := seen[trimmed]; exists {
			return nil, errors.New(errors.CodeEmployeeCollectionVoucherInvalid)
		}
		seen[trimmed] = struct{}{}
		normalized = append(normalized, trimmed)
	}
	return normalized, nil
}