/**
 * 订阅 API 模块
 * 提供订阅管理相关接口（当前使用 mock 数据，后端就绪后切换）
 */
import apiClient from './client';

/** 套餐类型 */
export type PlanType = 'free' | 'standard' | 'pro' | 'enterprise';

/** 订阅状态 */
export type SubscriptionStatus = 'active' | 'expired' | 'cancelled' | 'trial';

/** 账单状态 */
export type BillingStatus = 'paid' | 'pending' | 'failed' | 'refunded';

/** 计费周期 */
export type BillingCycle = 'monthly' | 'yearly';

/** 套餐信息 */
export interface Plan {
  id: PlanType;
  name: string;
  price: number | null;
  yearly_price?: number | null;
  description: string;
  recommended: boolean;
  features: string[];
}

/** 当前订阅信息 */
export interface SubscriptionInfo {
  id: string;
  plan_id: PlanType;
  plan_name: string;
  status: SubscriptionStatus;
  billing_cycle: BillingCycle;
  current_period_start: string;
  current_period_end: string;
  amount: number;
  auto_renew: boolean;
  created_at: string;
}

/** 账单记录 */
export interface BillingRecord {
  id: string;
  plan_name: string;
  amount: number;
  billing_cycle: BillingCycle;
  status: BillingStatus;
  payment_method: string;
  created_at: string;
  invoice_url?: string;
}

/** 升级/降级请求 */
export interface ChangePlanRequest {
  target_plan_id: PlanType;
  billing_cycle: BillingCycle;
}

/** 升级/降级响应 */
export interface ChangePlanResponse {
  success: boolean;
  message: string;
  new_subscription?: SubscriptionInfo;
}

// ============ Mock 数据 ============

const MOCK_SUBSCRIPTION: SubscriptionInfo = {
  id: 'sub-001',
  plan_id: 'standard',
  plan_name: '标准版',
  status: 'active',
  billing_cycle: 'monthly',
  current_period_start: '2026-06-01T00:00:00Z',
  current_period_end: '2026-07-01T00:00:00Z',
  amount: 99,
  auto_renew: true,
  created_at: '2026-03-01T00:00:00Z',
};

const MOCK_BILLING_RECORDS: BillingRecord[] = [
  {
    id: 'bill-001', plan_name: '标准版', amount: 99,
    billing_cycle: 'monthly', status: 'paid', payment_method: '微信支付',
    created_at: '2026-06-01T00:00:00Z', invoice_url: '#',
  },
  {
    id: 'bill-002', plan_name: '标准版', amount: 99,
    billing_cycle: 'monthly', status: 'paid', payment_method: '微信支付',
    created_at: '2026-05-01T00:00:00Z', invoice_url: '#',
  },
  {
    id: 'bill-003', plan_name: '标准版', amount: 99,
    billing_cycle: 'monthly', status: 'paid', payment_method: '支付宝',
    created_at: '2026-04-01T00:00:00Z', invoice_url: '#',
  },
];

/** 是否使用 mock 数据（后端就绪后改为 false） */
const USE_MOCK = true;

// ============ API 函数 ============

/** 获取当前订阅信息 */
export const getCurrentSubscription = async (): Promise<SubscriptionInfo> => {
  if (USE_MOCK) {
    await new Promise((resolve) => setTimeout(resolve, 300));
    return MOCK_SUBSCRIPTION;
  }
  const response = await apiClient.get('/subscription/current');
  return response.data;
};

/** 获取账单记录列表 */
export const getBillingRecords = async (): Promise<BillingRecord[]> => {
  if (USE_MOCK) {
    await new Promise((resolve) => setTimeout(resolve, 300));
    return MOCK_BILLING_RECORDS;
  }
  const response = await apiClient.get('/subscription/billing');
  return response.data;
};

/** 升级/降级套餐 */
export const changePlan = async (request: ChangePlanRequest): Promise<ChangePlanResponse> => {
  if (USE_MOCK) {
    await new Promise((resolve) => setTimeout(resolve, 1000));
    return {
      success: true,
      message: '套餐变更成功',
      new_subscription: {
        ...MOCK_SUBSCRIPTION,
        plan_id: request.target_plan_id,
        plan_name: request.target_plan_id === 'pro' ? '专业版' : request.target_plan_id === 'standard' ? '标准版' : '体验版',
      },
    };
  }
  const response = await apiClient.post('/subscription/change', request);
  return response.data;
};

/** 取消订阅 */
export const cancelSubscription = async (): Promise<{ success: boolean; message: string }> => {
  if (USE_MOCK) {
    await new Promise((resolve) => setTimeout(resolve, 800));
    return { success: true, message: '订阅已取消，当前周期结束后停止服务' };
  }
  const response = await apiClient.post('/subscription/cancel');
  return response.data;
};

/** 切换自动续费 */
export const toggleAutoRenew = async (enabled: boolean): Promise<{ success: boolean; message: string }> => {
  if (USE_MOCK) {
    await new Promise((resolve) => setTimeout(resolve, 300));
    return { success: true, message: enabled ? '已开启自动续费' : '已关闭自动续费' };
  }
  const response = await apiClient.post('/subscription/auto-renew', { enabled });
  return response.data;
};