import Taro from '@tarojs/taro';
import type { WechatShareData } from '@dukang/weixin-sdk';
import { getWechatShareLink, isWechatBrowser, isMiniProgram } from '@dukang/weixin-sdk';
import {
  applyShareTitleTemplate,
  DEFAULT_SHARE_DESC,
  DEFAULT_SHARE_HINT,
  DEFAULT_SHARE_TITLE,
  resolveMiniShareRuntime,
  type ClientRuntimeConfig,
  type MiniShareRuntime,
  type MiniShareSceneConfig,
} from '@dukang/shared-types';
import { toast } from './api';
import { getBrandAssetsSync, loadBrandAssets } from './brand-assets';
import { fetchClientConfig } from './pay-wechat';
import { isWechatEnv, weixinSdk } from './weixin';

export type ShareScene =
  | 'home'
  | 'stores'
  | 'storeDetail'
  | 'benefit'
  | 'mine'
  | 'productDetail'
  | 'orderDetail';

export { DEFAULT_SHARE_TITLE, DEFAULT_SHARE_DESC };

export const WECHAT_SHARE_HINT = DEFAULT_SHARE_HINT;

const FALLBACK_SHARE: MiniShareRuntime = resolveMiniShareRuntime({});

let shareCached: MiniShareRuntime | null = null;

export function getShareRuntimeSync(): MiniShareRuntime {
  return shareCached ?? FALLBACK_SHARE;
}

export function applyShareFromClientConfig(config?: ClientRuntimeConfig | null) {
  if (config?.share) {
    shareCached = config.share;
    return shareCached;
  }
  return getShareRuntimeSync();
}

export async function loadShareConfig(force = false): Promise<MiniShareRuntime> {
  if (!force && shareCached) return shareCached;
  try {
    const cfg = await fetchClientConfig();
    if (cfg?.share) {
      shareCached = cfg.share;
      return shareCached;
    }
  } catch {
    /* ignore */
  }
  shareCached = FALLBACK_SHARE;
  return shareCached;
}

export function getDefaultShareImageUrl(): string {
  const share = getShareRuntimeSync();
  return share.default.imageUrl || getBrandAssetsSync().brandLogoUrl;
}

export function getShareHint(): string {
  return getShareRuntimeSync().hint || DEFAULT_SHARE_HINT;
}

/** 预热分享配置与品牌图 */
export function prefetchShareBrandAssets() {
  void loadBrandAssets();
  void loadShareConfig();
}

function sceneConfig(scene?: ShareScene): MiniShareSceneConfig {
  const runtime = getShareRuntimeSync();
  if (!scene) return runtime.default;
  return runtime[scene] ?? runtime.default;
}

/**
 * 组装页面分享：场景配置优先；空字段用 dynamic → 默认分享。
 * orderDetail 标题支持 {productName}。
 */
export function buildSceneSharePayload(
  scene: ShareScene,
  options?: {
    path?: string;
    /** 业务动态标题（场景配置为空时使用） */
    dynamicTitle?: string | null;
    dynamicDesc?: string | null;
    dynamicImageUrl?: string | null;
    titleVars?: Record<string, string | undefined | null>;
  },
): PageSharePayload {
  const def = getShareRuntimeSync().default;
  const sc = sceneConfig(scene);
  let title = (sc.title || '').trim();
  if (title && options?.titleVars) {
    const vars = options.titleVars;
    const missingRequired = Object.entries(vars).some(
      ([key, value]) => title.includes(`{${key}}`) && !(value != null && String(value).trim()),
    );
    title = missingRequired ? '' : applyShareTitleTemplate(title, vars);
  }
  if (!title) {
    title = (options?.dynamicTitle || '').trim() || def.title;
  }
  const desc = (sc.desc || '').trim() || (options?.dynamicDesc || '').trim() || def.desc;
  const imgUrl =
    (sc.imageUrl || '').trim() ||
    (options?.dynamicImageUrl || '').trim() ||
    def.imageUrl ||
    getDefaultShareImageUrl();
  return {
    title,
    desc,
    path: options?.path,
    imgUrl,
  };
}

export function buildDefaultShareData(
  overrides?: Partial<WechatShareData>,
): WechatShareData {
  let link = overrides?.link;
  if (!link) {
    if (process.env.TARO_ENV === 'h5' && typeof window !== 'undefined') {
      link = getWechatShareLink();
    } else {
      link = '';
    }
  }
  const def = getShareRuntimeSync().default;
  return {
    title: overrides?.title ?? def.title,
    desc: overrides?.desc ?? def.desc,
    link,
    imgUrl: overrides?.imgUrl ?? getDefaultShareImageUrl(),
  };
}

/** 配置 H5 微信内右上角分享卡片 */
export async function applyWechatShare(
  overrides?: Partial<WechatShareData>,
): Promise<void> {
  if (process.env.TARO_ENV !== 'h5') return;
  if (!isWechatBrowser()) return;
  await weixinSdk.setShare(buildDefaultShareData(overrides));
}

export type PageSharePayload = {
  title?: string;
  desc?: string;
  /** 小程序分享 path，如 /pages/product-detail/index?id=1 */
  path?: string;
  imgUrl?: string;
  /** H5 自定义分享 link，默认当前页 */
  link?: string;
};

/**
 * 点击「分享」按钮。
 * H5：走微信 JSSDK 配置分享卡片，并尝试 invoke 调起面板；否则返回需展示引导蒙层。
 */
export async function handleShareButtonClick(
  payload?: PageSharePayload,
): Promise<{ showGuide: boolean }> {
  if (process.env.TARO_ENV === 'weapp' || isMiniProgram()) {
    try {
      await Taro.showShareMenu({ withShareTicket: true, showShareItems: ['shareAppMessage', 'shareTimeline'] });
    } catch {
      try {
        await Taro.showShareMenu({ withShareTicket: true });
      } catch {
        /* ignore */
      }
    }
    toast(getShareHint());
    return { showGuide: false };
  }

  if (!isWechatEnv()) {
    toast('请在微信内打开后分享');
    return { showGuide: false };
  }

  const data = buildDefaultShareData({
    title: payload?.title,
    desc: payload?.desc,
    imgUrl: payload?.imgUrl,
    link: payload?.link,
  });

  try {
    const result = await weixinSdk.share(data);
    if (result.invoked) {
      return { showGuide: false };
    }
    toast(getShareHint());
    return { showGuide: true };
  } catch (e) {
    toast(e instanceof Error ? e.message : '分享配置失败，请刷新后重试');
    return { showGuide: true };
  }
}

/** 供 useShareAppMessage 使用的标题/路径/图 */
export function toWeappShareMessage(payload?: PageSharePayload) {
  const def = getShareRuntimeSync().default;
  return {
    title: payload?.title || def.title,
    path: payload?.path || '/pages/home/index',
    imageUrl: payload?.imgUrl || getDefaultShareImageUrl(),
  };
}

/** 供 useShareTimeline */
export function toWeappShareTimeline(payload?: PageSharePayload, query = '') {
  const def = getShareRuntimeSync().default;
  return {
    title: payload?.title || def.title,
    query,
    imageUrl: payload?.imgUrl || getDefaultShareImageUrl(),
  };
}