// 公共图片上传：选图（仅图片）→ 上传后端（/api/upload，MD5 去重）→ 返回 {id,url,md5}
const { uploadFile } = require('./request.js');

const IMG_EXT = ['jpg', 'jpeg', 'png', 'gif', 'webp', 'bmp', 'heic', 'heif'];

// 仅允许图片：按扩展名二次校验（chooseMedia mediaType 已限制，这里双保险）
function isImagePath(p) {
  const m = /\.([a-zA-Z0-9]+)(\?.*)?$/.exec(p || '');
  return !!m && IMG_EXT.indexOf(m[1].toLowerCase()) >= 0;
}

// 选择并上传图片，返回 Promise<[{id,url,md5}]>。用户取消时 reject({canceled:true})。
function chooseAndUploadImages(count) {
  count = count || 1;
  return new Promise((resolve, reject) => {
    wx.chooseMedia({
      count,
      mediaType: ['image'], // 仅图片，不允许视频/文件
      sizeType: ['compressed'],
      sourceType: ['album', 'camera'],
      success(res) {
        const files = (res.tempFiles || []).filter((f) => isImagePath(f.tempFilePath));
        if (!files.length) {
          reject(new Error('只能上传图片文件'));
          return;
        }
        wx.showLoading({ title: '上传中...', mask: true });
        Promise.all(files.map((f) => uploadFile(f.tempFilePath)))
          .then((list) => {
            wx.hideLoading();
            resolve(list);
          })
          .catch((e) => {
            wx.hideLoading();
            reject(e);
          });
      },
      fail(err) {
        const msg = (err && err.errMsg) || '';
        if (/cancel/i.test(msg)) {
          reject({ canceled: true });
          return;
        }
        reject(new Error(msg || '选择图片失败'));
      },
    });
  });
}

// 单张图片，返回 Promise<{id,url,md5}>
function chooseAndUploadImage() {
  return chooseAndUploadImages(1).then((list) => list[0]);
}

module.exports = { chooseAndUploadImages, chooseAndUploadImage, isImagePath };