// frontend/composables/useShare.js
// 分享状态机 + 合成调度 + 错误处理 + 监控埋点
// (spec § 5 + § 5.3.1 + § 7 + § 8)

import { ref, nextTick, onBeforeUnmount } from 'vue';
import { onLoad, onShow, onHide, onUnload } from '@dcloudio/uni-app';
import { composeShareImage, computeComposeKey } from '@/utils/image-compositor.js';
import { pickRandomSlogan } from '@/utils/brand-slogans.js';
import { getShareQrcodeApi, trackShareApi } from '@/utils/api.js';

const APP_PACKAGES = {
  weixin_friend: { pname: 'com.tencent.mm',           bundleid: 'com.tencent.xinWeChat' },
  weixin_moment: { pname: 'com.tencent.mm',           bundleid: 'com.tencent.xinWeChat' },
  qq:            { pname: 'com.tencent.mobileqq',     bundleid: 'com.tencent.mqq' },
  qq_zone:       { pname: 'com.tencent.mobileqq',     bundleid: 'com.tencent.mqq' },
  sinaweibo:     { pname: 'com.sina.weibo',           bundleid: 'com.sina.weibo' }
};

const SHARE_TIMEOUT = {
  weixin_friend: 5000, weixin_moment: 5000,
  qq: 5000, qq_zone: 5000,
  sinaweibo: 15000,
  save_image: 8000
};

function reportEvent(eventName, payload) {
  try { uni.report(eventName, payload); } catch { /* dev/test */ }
}

function isUserCancel(errMsg = '') {
  return /cancel|取消/i.test(errMsg);
}

export function useShare(props) {
  // ============ State ============
  const state = ref('idle'); // idle | composing | sharing | done | error
  const errorMsg = ref('');
  const systemType = ref('');
  const currentSlogan = ref(pickRandomSlogan());
  const failCount = ref(0); // L3 degradation counter

  // ============ Timers ============
  const shareTimeoutTimer = ref(null);
  const fallbackTimer = ref(null);
  function clearShareTimers() {
    if (shareTimeoutTimer.value) { clearTimeout(shareTimeoutTimer.value); shareTimeoutTimer.value = null; }
    if (fallbackTimer.value)     { clearTimeout(fallbackTimer.value);     fallbackTimer.value = null; }
  }

  // ============ Lifecycle ============
  (async () => {
    try { const info = await uni.getSystemInfo(); systemType.value = info.platform || 'other'; }
    catch { systemType.value = 'other'; }
  })();
  onShow(() => {
    if (state.value === 'sharing') {
      fallbackTimer.value = setTimeout(() => { if (state.value === 'sharing') state.value = 'idle'; }, 8000);
    }
  });
  onHide(() => {
    if (shareTimeoutTimer.value) { clearTimeout(shareTimeoutTimer.value); shareTimeoutTimer.value = null; }
  });
  onBeforeUnmount(clearShareTimers);

  // ============ L1 Cache ============
  const l1Cache = new Map();

  // ============ Helpers ============
  function getCurrentUser() {
    const userStr = uni.getStorageSync('user');
    if (!userStr) return null;
    try { return JSON.parse(userStr); } catch { return null; }
  }

  // 后端 TrackShareRequest 字段是 int64,前端 props 是 string,转 number
  function toInt64(v) {
    if (v === null || v === undefined || v === '') return 0;
    const n = typeof v === 'string' ? parseInt(v, 10) : Number(v);
    return Number.isFinite(n) ? n : 0;
  }

  async function isAppInstalled(action) {
    if (typeof plus === 'undefined' || !plus.runtime) return true;
    const pkg = APP_PACKAGES[action];
    if (!pkg) return true;
    return new Promise(resolve => {
      plus.runtime.isApplicationExist({ pname: pkg.pname, bundleid: pkg.bundleid }, e => resolve(!!e.exist));
    });
  }

  async function downloadLocal(remoteUrl) {
    if (!remoteUrl) return '';
    if (typeof remoteUrl !== 'string') {
      console.warn('[useShare] downloadLocal expected string, got', typeof remoteUrl);
      return '';
    }
    // data: URL 直接返回
    if (remoteUrl.startsWith('data:')) return remoteUrl;
    // /static/... 是 app 包内静态资源。
    // canvas drawImage 需要真实文件路径(不接受 /static/ 相对路径或 data URI)
    // 把 /static/foo 拷贝到 _doc/(可写目录)拿到绝对路径给 canvas 用
    if (remoteUrl.startsWith('/static/')) {
      return await copyStaticToDoc(remoteUrl);
    }
    // http/https 用 uni.getImageInfo 拿本地临时文件 res.path
    // (相较 uni.downloadFile,getImageInfo 专用于图片,内部走图像解码路径,
    //  返回的本地 path canvas drawImage 直接可用,且拿图 + 解析一步到位)
    const res = await uni.getImageInfo({ src: remoteUrl });
    if (!res || !res.path) throw new Error('getImageInfo failed: no path returned');
    // Android 上 res.path 是 'file:///storage/...',app-plus canvas drawImage 不接受 file:// 前缀,
    // 会解析失败报 'image argument is a canvas element with a width or height of 0'。
    // 统一剥成裸路径 '/storage/...' 与 copyStaticToDoc 返回格式一致
    return res.path.replace(/^file:\/\//, '');
  }

  // 把 /static/ 静态资源复制到 _doc/ 可写目录(canvas drawImage 需要绝对文件路径,
  // 且 native canvas 不接受 data: URI 也不接受 _www/ 前缀)
  // 复用 plus.io.copyTo 把文件从 _www 拷到 _doc
  function copyStaticToDoc(staticPath) {
    return new Promise((resolve) => {
      if (typeof plus === 'undefined' || !plus.io) {
        resolve(staticPath);
        return;
      }
      const fileName = staticPath.split('/').pop();
      const srcPath = '_www/' + staticPath.replace(/^\//, '');
      const dstPath = `_doc/${fileName}`;
      // 先确保 _doc 存在
      plus.io.resolveLocalFileSystemURL(
        '_doc/',
        (docDir) => {
          // 解析 _www 源文件
          plus.io.resolveLocalFileSystemURL(
            srcPath,
            (srcEntry) => {
              srcEntry.copyTo(
                docDir,
                fileName,
                (destEntry) => {
                  console.log('[useShare] static copied to', destEntry.fullPath);
                  resolve(destEntry.fullPath);
                },
                (copyErr) => {
                  console.warn('[useShare] static copy fail, fallback raw', copyErr);
                  resolve(staticPath);
                }
              );
            },
            (resolveErr) => {
              console.warn('[useShare] static resolve fail, fallback raw', resolveErr);
              resolve(staticPath);
            }
          );
        },
        (docErr) => {
          console.warn('[useShare] _doc resolve fail', docErr);
          resolve(staticPath);
        }
      );
    });
  }

  // 把文件复制到 plus.io.PRIVATE_DOC 沙盒目录(Android 10+ 分区存储要求)
  // 返回沙盒内的目标绝对路径,可供 plus.gallery.save 使用
  function copyToSandbox(tempPath) {
    return new Promise((resolve, reject) => {
      if (typeof plus === 'undefined' || !plus.io) {
        return reject(new Error('plus.io unavailable'));
      }
      const fileName = `share_${Date.now()}.png`;
      const sandboxRoot = plus.io.PRIVATE_DOC; // 应用沙盒 doc 目录
      const targetPath = `${sandboxRoot}/${fileName}`;

      // 8s 超时兜底(避免 plus.io 内部 hang 永远不回调)
      const timeoutId = setTimeout(() => {
        console.warn('[useShare] copyToSandbox timeout');
        reject(new Error('copyToSandbox timeout(8s)'));
      }, 8000);

      // plus.io.resolveLocalFileSystemURL 拿到 source FileEntry
      plus.io.resolveLocalFileSystemURL(
        tempPath,
        (srcEntry) => {
          // 拿沙盒目录 DirectoryEntry
          plus.io.resolveLocalFileSystemURL(
            sandboxRoot,
            (sandboxDir) => {
              srcEntry.copyTo(
                sandboxDir,
                fileName,
                (destEntry) => {
                  clearTimeout(timeoutId);
                  console.log('[useShare] copyToSandbox done:', destEntry.fullPath);
                  resolve(destEntry.fullPath);
                },
                (copyErr) => {
                  clearTimeout(timeoutId);
                  console.warn('[useShare] copyToSandbox fail:', copyErr);
                  reject(new Error(copyErr.message || 'copyTo failed'));
                }
              );
            },
            (dirErr) => {
              clearTimeout(timeoutId);
              console.warn('[useShare] resolve sandbox dir fail:', dirErr);
              reject(new Error(dirErr.message || 'sandbox dir resolve failed'));
            }
          );
        },
        (srcErr) => {
          clearTimeout(timeoutId);
          console.warn('[useShare] resolve temp fail:', srcErr);
          reject(new Error(srcErr.message || 'temp resolve failed'));
        }
      );
    });
  }

  // 清理沙盒文件(异步,失败不抛)
  function cleanupSandboxFile(sandboxPath) {
    if (typeof plus === 'undefined' || !plus.io || !sandboxPath) return;
    plus.io.resolveLocalFileSystemURL(
      sandboxPath,
      (entry) => {
        try { entry.remove(() => {}, () => {}); } catch {}
      },
      () => {}
    );
  }

  async function fetchQrcode(assetId) {
    const user = getCurrentUser();
    if (!user?.uid) throw new Error('未登录');
    return getShareQrcodeApi(assetId, user.uid, systemType.value);
  }

  function trackShare(payload) {
    return trackShareApi(payload);
  }

  async function ensureLogin() {
    const user = getCurrentUser();
    if (!user?.uid) {
      uni.showToast({ title: '请先登录', icon: 'none' });
      setTimeout(() => uni.navigateTo({ url: '/pages/login/login' }), 800);
      return false;
    }
    return true;
  }

  function startShareTimeout(action) {
    const ms = SHARE_TIMEOUT[action] || 5000;
    shareTimeoutTimer.value = setTimeout(() => {
      if (state.value === 'sharing') {
        state.value = 'error';
        errorMsg.value = '分享超时，请重试';
        uni.showToast({ title: errorMsg.value, icon: 'none' });
        const userId = getCurrentUser()?.uid || 0;
        trackShare({ asset_id: toInt64(typeof props.getAssetId === 'function' ? props.getAssetId() : props.assetId), sharer_user_id: toInt64(userId), system_type: systemType.value, share_target: action, result: 'fail_other', client_ts: Date.now() });
      }
    }, ms);
  }

  // ============ Core ============
  async function pick(action) {
    if (!(await ensureLogin())) return;

    state.value = 'composing';
    errorMsg.value = '';

    // 关键:等 Vue 把 canvas 元素挂载到 DOM(ShareModal template 用 v-if 控制)
    // 否则 uni.createCanvasContext 找不到 canvas,后续 drawImage 全无效
    console.log('[useShare] pick start, action=', action);
    await nextTick();
    await new Promise(r => setTimeout(r, 50)); // 多等 50ms 让 uni-app 完成 native canvas 初始化
    console.log('[useShare] after nextTick + 50ms');

    try {
      // 1. App 探测
      if (action !== 'save_image') {
        const installed = await isAppInstalled(action);
        if (!installed) {
          const labelMap = { weixin_friend: '微信', weixin_moment: '微信', qq: 'QQ', qq_zone: 'QQ', sinaweibo: '微博' };
          uni.showToast({ title: `请先安装${labelMap[action]}`, icon: 'none' });
          state.value = 'idle';
          const userId = getCurrentUser().uid;
          await trackShare({ asset_id: toInt64(typeof props.getAssetId === 'function' ? props.getAssetId() : props.assetId), sharer_user_id: toInt64(userId), system_type: systemType.value, share_target: action, result: 'fail_app_missing', client_ts: Date.now() });
          return;
        }
      }

      // 2. 缓存查询 — props 通过 getter functions 取实时值(避免 setup snapshot 拿到空)
      const coverUrl  = typeof props.getCoverUrl  === 'function' ? props.getCoverUrl()  : props.coverUrl;
      const qrcodeUrl = typeof props.getQrcodeUrl === 'function' ? props.getQrcodeUrl() : props.qrcodeUrl;
      const avatarUrl = typeof props.getAvatarUrl === 'function' ? props.getAvatarUrl() : props.avatarUrl;
      const nickname  = typeof props.getNickname  === 'function' ? props.getNickname()  : props.nickname;
      const assetId   = typeof props.getAssetId   === 'function' ? props.getAssetId()   : props.assetId;
      const displayTxHash = typeof props.getDisplayTxHash === 'function' ? props.getDisplayTxHash() : props.displayTxHash;

      const localPaths = await Promise.all([
        downloadLocal(coverUrl),
        downloadLocal(qrcodeUrl),
        downloadLocal(avatarUrl)
      ]);
      console.log('[useShare] qrcodeUrl =', qrcodeUrl);
  console.log('[useShare] avatarUrl =', avatarUrl);
  console.log('[useShare] coverLocal  =', localPaths[0]);
  console.log('[useShare] qrcodeLocal =', localPaths[1]);
  console.log('[useShare] avatarLocal =', localPaths[2]);
      const composeKey = computeComposeKey({
        coverLocalPath: localPaths[0], qrcodeLocalPath: localPaths[1], avatarLocalPath: localPaths[2],
        nickname, slogan: currentSlogan.value, displayTxHash
      });
      console.log(composeKey)
      let tempFilePath = l1Cache.get(composeKey);
      // 跳过 canvas 的条件:只有 cover 是 /static/ 才跳过(native canvas 不支持相对路径)
      // avatar/qrcode 即使是 /static/ 也让 canvas 跑(它能容忍某图层缺失,留空白)
      const coverIsStatic = localPaths[0] && localPaths[0].startsWith('/static/');
      if (!tempFilePath && !coverIsStatic) {
        try {
          const result = await Promise.race([
            composeShareImage({
              coverLocalPath: localPaths[0], qrcodeLocalPath: localPaths[1], avatarLocalPath: localPaths[2],
              nickname, slogan: currentSlogan.value, displayTxHash,
              canvasId: props.canvasId || 'shareCanvas'
            }, props.vm),
            new Promise((_, reject) => setTimeout(() => reject(new Error('canvas 合成超时(8s)')), 8000))
          ]);
          tempFilePath = result.tempFilePath;
          if (tempFilePath) l1Cache.set(composeKey, tempFilePath);
        } catch (canvasErr) {
          console.warn('[useShare] canvas 合成失败,降级用 cover 图:', canvasErr.message || canvasErr);
          tempFilePath = localPaths[0];
          if (!tempFilePath) {
            throw new Error('cover 图也下载失败,请检查 props.coverUrl 是否有效');
          }
          uni.showToast({ title: '水印图生成失败,使用原图', icon: 'none' });
        }
      } else if (!tempFilePath) {
        // cover 是 /static/ 相对路径,native canvas 无法加载,直接用 cover 原图
        console.log('[useShare] cover 是 /static/ 路径,跳过 canvas 直接用 cover');
        tempFilePath = localPaths[0];
        if (!tempFilePath) {
          throw new Error('cover 图也下载失败,请检查 props.coverUrl 是否有效');
        }
      }

      // 3. 分发 + 监控
      state.value = 'sharing';
      const startTs = Date.now();
      const userId = getCurrentUser().uid;
      const commonPayload = { asset_id: toInt64(typeof props.getAssetId === 'function' ? props.getAssetId() : props.assetId), user_id: toInt64(userId), system_type: systemType.value };

      if (action === 'save_image') {
        reportEvent('save_image_click', commonPayload);
      } else {
        reportEvent('share_action_click', { ...commonPayload, target: action });
      }

      startShareTimeout(action);

      let result = 'fail_other';
      let errMsg = '';
      if (action === 'save_image') {
        console.log('[useShare] before saveImageToPhotosAlbum, filePath =', tempFilePath, 'state=', state.value);
        try {
          // 优先:uni.saveImageToPhotosAlbum 直接试(快,在 Android 10- 或非严格分区存储下能成功)
          await new Promise((resolve, reject) => {
            uni.saveImageToPhotosAlbum({
              filePath: tempFilePath,
              success: (res) => {
                console.log('[useShare] uni.saveImageToPhotosAlbum success', res);
                uni.showToast({ title: '已保存到相册' });
                resolve();
              },
              fail: (e) => {
                console.warn('[useShare] uni.saveImageToPhotosAlbum fail, fallback to plus.gallery.save', e);
                reject(new Error(e.errMsg || JSON.stringify(e) || 'save failed'));
              }
            });
          });
        } catch (eUni) {
          // 兜底:Android 10+ 严格分区存储场景,uni.saveImageToPhotosAlbum 会因 code=12 失败
          // 此时需要走沙盒路径:plus.io.copyTo + plus.gallery.save
          if (typeof plus === 'undefined' || !plus.gallery || typeof plus.gallery.save !== 'function') {
            throw new Error('plus.gallery unavailable and uni.saveImageToPhotosAlbum failed: ' + eUni.message);
          }
          try {
            const sandboxPath = await copyToSandbox(tempFilePath);
            console.log('[useShare] sandbox path =', sandboxPath);
            await new Promise((resolve, reject) => {
              plus.gallery.save(
                sandboxPath,
                (res) => {
                  console.log('[useShare] plus.gallery.save success', res);
                  uni.showToast({ title: '已保存到相册' });
                  cleanupSandboxFile(sandboxPath);
                  resolve();
                },
                (err) => {
                  console.warn('[useShare] plus.gallery.save fail', err);
                  cleanupSandboxFile(sandboxPath);
                  reject(err);
                }
              );
            });
          } catch (eSandbox) {
            // 两条路都失败 — 把详细错误抛出
            throw new Error(`uni.saveImageToPhotosAlbum: ${eUni.message}; plus.gallery.save: ${eSandbox.message}`);
          }
        }
        // errMsg 分类:区分 cancel / permission / 其他失败
        errMsg = '';
        result = 'success';
        reportEvent('save_image_result', { ...commonPayload, result, duration_ms: Date.now() - startTs });
      } else {
        const provider = action.startsWith('weixin') ? 'weixin' : (action === 'qq' || action === 'qq_zone') ? 'qq' : 'sinaweibo';
        const scene = action === 'weixin_moment' ? 'WXSceneTimeline' : action.startsWith('weixin') ? 'WXSceneSession' : undefined;
        const shareRes = await new Promise((resolve) => {
          uni.share({
            provider, scene, imageUrl: tempFilePath,
            success: (r) => resolve({ ok: true, msg: r.errMsg }),
            fail: (e) => resolve({ ok: false, msg: e.errMsg || 'share failed' })
          });
        });
        if (shareRes.ok) result = 'success';
        else if (isUserCancel(shareRes.msg)) result = 'cancel';
        errMsg = shareRes.msg;
        reportEvent('share_result', { ...commonPayload, target: action, result, duration_ms: Date.now() - startTs });
      }

      clearShareTimers();

      if (result === 'success') {
        state.value = 'done';
        // action-aware 文案:save_image 已在成功回调里弹过"已保存到相册",这里跳过避免覆盖;
        // 其他 action 走分享平台,统一提示"分享成功"
        if (action !== 'save_image') {
          uni.showToast({ title: '分享成功' });
        }
        failCount.value = 0;
        setTimeout(() => { if (state.value === 'done') state.value = 'idle'; }, 2000);
      } else if (result === 'cancel') {
        state.value = 'idle';
      } else {
        state.value = 'error';
        errorMsg.value = '分享失败，请稍后再试';
        uni.showToast({ title: errorMsg.value, icon: 'none' });
        failCount.value += 1;
      }

      await trackShare({
        asset_id: toInt64(typeof props.getAssetId === 'function' ? props.getAssetId() : props.assetId), sharer_user_id: toInt64(userId),
        system_type: systemType.value, share_target: action, result,
        client_ts: startTs, extra: { duration_ms: Date.now() - startTs, err: errMsg }
      });
    } catch (e) {
      clearShareTimers();
      state.value = 'error';
      errorMsg.value = e.message || '未知错误';
      uni.showToast({ title: errorMsg.value, icon: 'none' });
      failCount.value += 1;
    }
  }

  return { state, errorMsg, systemType, currentSlogan, failCount, pick };
}