/**
 * 微信订阅消息工具
 * 统一管理订阅消息的请求和状态
 * 
 * 服务端记录的是授权登记，不代表微信侧仍有剩余次数。
 */
const { api } = require('./request');

// 操作和打卡共用同一模板、同一份一次性授权。
const SUBSCRIBE_TEMPLATES = {
  notify: 'K_iQMwE_jre0j6QDVL78DZz7wiR1SKVY5h2YJCK6uPU',
};

// 只合并正在进行的授权请求，后续用户点击仍可补充一次性授权。
let _pendingSubscribe = null;

/**
 * 请求用户订阅指定模板
 * @param {string|string[]} templateTypes - 模板类型或模板类型数组
 * @returns {Promise<object>} 订阅结果 { templateType: true/false }
 */
function requestSubscribe(templateTypes, options = {}) {
  if (_pendingSubscribe) return _pendingSubscribe;
  const pending = new Promise((resolve, reject) => {
    if (!Array.isArray(templateTypes)) {
      templateTypes = [templateTypes];
    }

    // 获取模板ID列表
    const tmplIds = templateTypes
      .map(type => SUBSCRIBE_TEMPLATES[type])
      .filter(id => id && id !== 'TEMPLATE_ID_');

    if (tmplIds.length === 0) {
      console.warn('[subscribe] 模板ID未配置，请在微信小程序管理后台申请模板后更新');
      resolve({});
      return;
    }

    wx.requestSubscribeMessage({
      tmplIds: tmplIds,
      success: (res) => {
        // 处理每个模板的授权结果
        const results = {};
        templateTypes.forEach((type) => {
          const tmplId = SUBSCRIBE_TEMPLATES[type];
          const status = res[tmplId];
          results[type] = status === 'accept';
        });

        // 将授权结果同步到后端
        syncSubscribeResults(results, options).then(() => resolve(results), reject);
      },
      fail: (err) => {
        console.error('[subscribe] 请求订阅失败:', err);
        reject(err);
      }
    });
  });
  _pendingSubscribe = pending.finally(() => { _pendingSubscribe = null; prepareLoginRenewal(); });
  return _pendingSubscribe;
}

/**
 * 将订阅结果同步到后端
 */
function syncSubscribeResults(results, options) {
  return Promise.all(Object.keys(results).filter(type => results[type]).map(type => {
    return api.subscribeTemplate({template_type:type, template_id:SUBSCRIBE_TEMPLATES[type]}, options).then(result => {
      if (!result || !result.success) throw new Error('订阅授权保存失败');
      wx.setStorageSync('subscribed_' + type, true);
    });
  }));
}

/**
 * 获取用户当前的订阅状态
 * 从后端获取
 * @param {boolean} forceRefresh - 保留旧调用参数
 * @returns {Promise<object>} 订阅状态 { template_type: true/false }
 */
async function getSubscribeStatus(forceRefresh = false) {
  try {
    const res = await api.mySubscribeTemplates();
    const status = {};
    Object.keys(SUBSCRIBE_TEMPLATES).forEach(type => {
      status[type] = !!SUBSCRIBE_TEMPLATES[type] && res.templates[type] === SUBSCRIBE_TEMPLATES[type];
    });
    return status;
  } catch (e) {
    return {};
  }
}

module.exports = {
  requestSubscribe,
  resetLoginRenewal,
  prepareLoginRenewal,
  tryLoginRenewal,
  getSubscribeStatus,
  isTemplateConfigured: type => !!SUBSCRIBE_TEMPLATES[type],
  subscribeErrorMessage
};

function subscribeErrorMessage(error) {
  const code = Number(error && error.errCode);
  if (code === 20001) return '微信未找到该提醒模板，请核对当前小程序的模板配置';
  if (code === 20004) return '微信消息通知总开关已关闭，请在小程序设置中开启';
  if (code === 10002 || code === 10003) return '网络异常，暂时无法订阅，请稍后重试';
  return error && (error.error || error.message) || '订阅失败，请稍后重试';
}

// Reading settings at login never asks for authorization. Only a later real tap
// may renew, and only when WeChat reports a remembered acceptance.
let renewal = {generation:0,userId:'',allowed:false,attempted:false};
function resetLoginRenewal() {
  renewal = {generation:renewal.generation+1,userId:'',allowed:false,attempted:false};
}
function prepareLoginRenewal() {
  renewal.allowed = false;
  if (typeof wx.getSetting !== 'function' || typeof wx.getStorageSync !== 'function') return;
  const userId = String(wx.getStorageSync('userId') || '');
  if (!userId) return;
  if (renewal.userId && renewal.userId !== userId) resetLoginRenewal();
  renewal.userId = userId;
  const generation = ++renewal.generation;
  try {
    wx.getSetting({withSubscriptions:true,success(result){
      if (renewal.generation !== generation || String(wx.getStorageSync('userId') || '') !== userId) return;
      const settings = result.subscriptionsSetting || {};
      renewal.allowed = settings.mainSwitch === true && !!settings.itemSettings && settings.itemSettings[SUBSCRIBE_TEMPLATES.notify] === 'accept';
    },fail(){ /* Unknown permission means no automatic request. */ }});
  } catch(error) { /* Unsupported API: keep the manual entry. */ }
}
function tryLoginRenewal() {
  const app = typeof getApp === 'function' ? getApp() : null;
  if (!app || !app.globalData || app.globalData.authState !== 'ready' || !renewal.allowed || renewal.attempted) return;
  if (!wx.getStorageSync('coupleId') || wx.getStorageSync('subscribed_notify') === false || String(wx.getStorageSync('userId') || '') !== renewal.userId) return;
  renewal.attempted = true;
  // Intentionally no await before requesting: preserve this tap's user gesture.
  return requestSubscribe('notify', {silent:true}).catch(error => {
    console.warn('[subscribe] 本次静默续订未完成，保留手动订阅入口:',error);
    return {};
  });
}