/**
 * License Issuer — 生成签名 License 文件
 *
 * 用法:
 *   import { issueLicense } from '@gloablehive/license';
 *   const file = issueLicense({ merchantId: 'M001', merchantName: '水果店', plan: 'basic' }, SECRET);
 *   fs.writeFileSync('license.json', JSON.stringify(file, null, 2));
 */

import * as crypto from 'crypto';
import { signPayload, getMachineId } from './license-guard.js';
import type { LicenseFile, LicensePayload, LicensePlan } from './types.js';
import { PLAN_PRESETS } from './types.js';

export interface IssueOptions {
  /** 商户 ID */
  merchantId: string;

  /** 商户名称 */
  merchantName: string;

  /** 套餐 */
  plan: LicensePlan;

  /** 有效天数 (默认 365) */
  validDays?: number;

  /** 是否绑定当前机器 (默认 false) */
  bindMachine?: boolean;

  /** 自定义功能覆盖 */
  featuresOverride?: Partial<LicensePayload['features']>;

  /** 自定义配额覆盖 */
  quotasOverride?: Partial<LicensePayload['quotas']>;
}

/**
 * 生成签名的 License 文件对象
 */
export function issueLicense(opts: IssueOptions, secret: string): LicenseFile {
  const preset = PLAN_PRESETS[opts.plan];
  const now = new Date();
  const validDays = opts.validDays ?? 365;
  const expires = new Date(now.getTime() + validDays * 24 * 60 * 60 * 1000);

  const payload: LicensePayload = {
    id: crypto.randomUUID(),
    merchantId: opts.merchantId,
    merchantName: opts.merchantName,
    plan: opts.plan,
    features: { ...preset.features, ...opts.featuresOverride },
    quotas: { ...preset.quotas, ...opts.quotasOverride },
    issuedAt: now.toISOString(),
    expiresAt: expires.toISOString(),
    machineId: opts.bindMachine ? getMachineId() : undefined,
  };

  const signature = signPayload(payload, secret);

  return {
    version: 1,
    payload,
    signature,
  };
}