import { URLS } from '../api/apiConfig';
import { TAxios } from '../api/TAxios';
import { types } from './actionTypes';

/**
 * PDF를 이미지로 변환
 * @param {string} pdfUrl - 변환할 PDF URL
 * @param {function} callback - 성공/실패 후 실행할 콜백 (error, imageUrl)
 */
export const convertPdfToImage = (pdfUrl, callback) => (dispatch, getState) => {
  dispatch({
    type: types.CONVERT_PDF_TO_IMAGE,
    payload: pdfUrl,
  });

  const onSuccess = (response) => {
    // retCode 체크 (프로젝트 API 규약: 200이어도 retCode로 성공/실패 구분)
    const retCode = response.headers?.retcode || response.headers?.retCode;

    if (retCode !== undefined && retCode !== 0 && retCode !== '0') {
      const error = new Error(`API Error: retCode=${retCode}`);
      dispatch({
        type: types.CONVERT_PDF_TO_IMAGE_FAILURE,
        payload: { pdfUrl, error },
      });
      callback && callback(error, null);
      return;
    }

    let imageUrl;
    try {
      if (response.data instanceof Blob) {
        if (response.data.size < 100) {
          throw new Error('Invalid image data (size too small)');
        }
        imageUrl = URL.createObjectURL(response.data);
      } else if (response.data instanceof ArrayBuffer) {
        if (response.data.byteLength < 100) {
          throw new Error('Invalid image data (size too small)');
        }
        const blob = new Blob([response.data], { type: 'image/png' });
        imageUrl = URL.createObjectURL(blob);
      } else {
        const blob = new Blob([response.data], { type: 'image/png' });
        imageUrl = URL.createObjectURL(blob);
      }

      dispatch({
        type: types.CONVERT_PDF_TO_IMAGE_SUCCESS,
        payload: { pdfUrl, imageUrl },
      });

      callback && callback(null, imageUrl);
    } catch (error) {
      dispatch({
        type: types.CONVERT_PDF_TO_IMAGE_FAILURE,
        payload: { pdfUrl, error },
      });
      callback && callback(error, null);
    }
  };

  const onFail = (error) => {
    dispatch({
      type: types.CONVERT_PDF_TO_IMAGE_FAILURE,
      payload: { pdfUrl, error },
    });
    callback && callback(error, null);
  };

  TAxios(
    dispatch,
    getState,
    'post',
    URLS.CONVERT_IMG,
    {},
    { pdfUrl },
    onSuccess,
    onFail,
    false,
    'blob'
  );
};

/**
 * 여러 PDF를 순차적으로 변환 (백그라운드)
 * @param {Array<string>} pdfUrls - 변환할 PDF URL 배열
 * @param {function} callback - 완료 후 실행할 콜백 (errors, results)
 */
export const convertMultiplePdfs = (pdfUrls, callback) => async (dispatch, getState) => {
  if (!pdfUrls || pdfUrls.length === 0) {
    callback && callback(null, []);
    return;
  }

  const results = [];
  const errors = [];

  for (let i = 0; i < pdfUrls.length; i++) {
    const pdfUrl = pdfUrls[i];

    await new Promise((resolve) => {
      dispatch(
        convertPdfToImage(pdfUrl, (error, imageUrl) => {
          if (error) {
            errors.push({ pdfUrl, error });
          } else {
            results.push({ pdfUrl, imageUrl });
          }
          resolve();
        })
      );
    });

    if (i < pdfUrls.length - 1) {
      await new Promise((resolve) => setTimeout(resolve, 100));
    }
  }

  callback && callback(errors.length > 0 ? errors : null, results);
};

/**
 * 변환된 이미지 데이터 초기화 (전체)
 */
export const clearConvertedImage = () => ({
  type: types.CLEAR_CONVERTED_IMAGE,
});

/**
 * 특정 PDF의 변환된 이미지 데이터 제거
 * @param {string} pdfUrl - 제거할 PDF URL
 */
export const clearConvertedImageByUrl = (pdfUrl) => ({
  type: types.CLEAR_CONVERTED_IMAGE_BY_URL,
  payload: pdfUrl,
});