interface NumRule {
  min?: number;
  max?: number;
  minMsg?: string;
  maxMsg?: string;
  posMsg?: string;
  optional?: boolean;
}

interface ValidateResult {
  ok: boolean;
  message: string;
}

export function num(rule: NumRule) {
  return {
    safeParse(value: number | undefined): ValidateResult {
      if (value === undefined || value === null) {
        return rule.optional ? { ok: true, message: '' } : { ok: false, message: posMsg || '请输入有效数值' };
      }
      if (isNaN(value)) return { ok: false, message: '请输入有效数值' };
      if (rule.min !== undefined && value < rule.min) return { ok: false, message: rule.minMsg || `数值不能低于${rule.min}` };
      if (rule.max !== undefined && value > rule.max) return { ok: false, message: rule.maxMsg || `数值不能高于${rule.max}` };
      return { ok: true, message: '' };
    },
  };
}

interface FieldRule {
  min?: number;
  max?: number;
  minMsg?: string;
  maxMsg?: string;
  optional?: boolean;
}

export function validateNum(value: number | undefined, label: string, rule: FieldRule): string | null {
  if (value === undefined || value === null) return rule.optional ? null : `${label}: 请输入有效数值`;
  if (isNaN(value)) return `${label}: 请输入有效数值`;
  if (rule.min !== undefined && value < rule.min) return `${label}: ${rule.minMsg ?? `数值不能低于${rule.min}`}`;
  if (rule.max !== undefined && value > rule.max) return `${label}: ${rule.maxMsg ?? `数值不能高于${rule.max}`}`;
  return null;
}

export function validateStr(value: string | undefined, maxLen: number, label: string): string | null {
  if (!value) return null;
  if (value.length > maxLen) return `${label}不能超过${maxLen}字`;
  return null;
}