/**
 * OmniCard AI (CRMmp) - 跨端统一图片上传核心业务驱动层 (UTS)
 * 严格遵循 uts 强类型、零 emoji 与 AGENTS.md 约束
 * 支持单图/多图上传、大图预览 (uni.previewImage)、独立删除与上限拦截
 */

export type ImageUploaderState = {
  images: string[];
  uploading: boolean;
  errorMessage: string;
};

export type ChooseImageCallbackRes = {
  tempFilePaths: string[];
};

export type ChooseImageOptions = {
  count?: number;
  sizeType?: string[];
  sourceType?: string[];
  success?: (res: ChooseImageCallbackRes) => void;
  fail?: (err: unknown) => void;
};

export type ImageUploaderOptions = {
  multiple?: boolean;
  maxCount?: number;
  sourceType?: string[];
  chooseImageFn?: (options: ChooseImageOptions) => void;
};

/**
 * 创建上传状态
 */
export function createImageUploaderState(initialImages?: string[]): ImageUploaderState {
  return {
    images: initialImages != null ? initialImages.slice() : [],
    uploading: false,
    errorMessage: '',
  };
}

/**
 * 追加图片 URL，并严格按 maxCount 截断
 */
export function addImageUrls(
  state: ImageUploaderState,
  urls: string[],
  maxCount: number = 9
): void {
  const nextList: string[] = [];
  for (let i = 0; i < state.images.length; i++) {
    nextList.push(state.images[i]);
  }
  for (let j = 0; j < urls.length; j++) {
    const url = urls[j].trim();
    if (url !== '') {
      nextList.push(url);
    }
  }
  state.images = nextList.slice(0, maxCount);
}

/**
 * 依据索引删除单张图片
 */
export function removeImageByIndex(
  state: ImageUploaderState,
  index: number
): void {
  if (index < 0 || index >= state.images.length) {
    return;
  }
  const nextList: string[] = [];
  for (let i = 0; i < state.images.length; i++) {
    if (i !== index) {
      nextList.push(state.images[i]);
    }
  }
  state.images = nextList;
}

/**
 * 清空所有图片
 */
export function clearAllImages(state: ImageUploaderState): void {
  state.images = [];
}

/**
 * 获取可用于全屏大图预览的 URL 数组
 */
export function resolvePreviewUrls(state: ImageUploaderState): string[] {
  return state.images.slice();
}

/**
 * 触发调用系统原生全屏大图放大预览
 */
export function previewImageAt(
  state: ImageUploaderState,
  currentUrlOrIndex: string | number
): void {
  const urls = resolvePreviewUrls(state);
  if (urls.length === 0) {
    return;
  }
  let current = '';
  if (typeof currentUrlOrIndex === 'number') {
    if (currentUrlOrIndex >= 0 && currentUrlOrIndex < urls.length) {
      current = urls[currentUrlOrIndex];
    } else {
      current = urls[0];
    }
  } else {
    current = currentUrlOrIndex;
  }

  // #ifndef UNI-APP-X-TEST
  try {
    if (typeof uni !== 'undefined' && typeof uni.previewImage === 'function') {
      uni.previewImage({
        urls,
        current,
      });
    }
  } catch (_e) {}
  // #endif
}

/**
 * 选择图片并执行上传流程
 */
export async function chooseAndUploadImages(
  state: ImageUploaderState,
  options?: ImageUploaderOptions
): Promise<boolean> {
  const opt = options != null ? options : {};
  const multiple = opt.multiple !== undefined ? opt.multiple : false;
  const maxCount = opt.maxCount !== undefined ? opt.maxCount : (multiple ? 9 : 1);
  const remainingCount = maxCount - state.images.length;

  if (remainingCount <= 0) {
    state.errorMessage = '已达到上传上限';
    return false;
  }

  const selectCount = multiple ? remainingCount : 1;
  const sourceTypes = opt.sourceType != null && opt.sourceType.length > 0
    ? opt.sourceType
    : ['album', 'camera'];

  state.uploading = true;
  state.errorMessage = '';

  return new Promise<boolean>((resolve) => {
    const chooseFn = opt.chooseImageFn != null
      ? opt.chooseImageFn
      : (typeof uni !== 'undefined' && typeof uni.chooseImage === 'function' ? uni.chooseImage : null);

    if (!chooseFn) {
      state.uploading = false;
      state.errorMessage = 'chooseImage 不可用';
      resolve(false);
      return;
    }

    try {
      chooseFn({
        count: selectCount,
        sourceType: sourceTypes,
        success: (res: ChooseImageCallbackRes) => {
          if (res.tempFilePaths != null && res.tempFilePaths.length > 0) {
            addImageUrls(state, res.tempFilePaths, maxCount);
            state.uploading = false;
            resolve(true);
          } else {
            state.uploading = false;
            resolve(false);
          }
        },
        fail: (err: unknown) => {
          state.uploading = false;
          let msg = '取消选择图片';
          if (err instanceof Error) {
            msg = err.message;
          }
          state.errorMessage = msg;
          resolve(false);
        },
      });
    } catch (e) {
      state.uploading = false;
      state.errorMessage = e instanceof Error ? e.message : '选择异常';
      resolve(false);
    }
  });
}