import { Map } from 'immutable';
import uuid from 'uuid/v4';
import { differenceBy } from 'lodash';
import {
  MEDIA_LIBRARY_OPEN,
  MEDIA_LIBRARY_CLOSE,
  MEDIA_LIBRARY_CREATE,
  MEDIA_INSERT,
  MEDIA_REMOVE_INSERTED,
  MEDIA_LOAD_REQUEST,
  MEDIA_LOAD_SUCCESS,
  MEDIA_LOAD_FAILURE,
  MEDIA_PERSIST_REQUEST,
  MEDIA_PERSIST_SUCCESS,
  MEDIA_PERSIST_FAILURE,
  MEDIA_DELETE_REQUEST,
  MEDIA_DELETE_SUCCESS,
  MEDIA_DELETE_FAILURE,
  MEDIA_DISPLAY_URL_REQUEST,
  MEDIA_DISPLAY_URL_SUCCESS,
  MEDIA_DISPLAY_URL_FAILURE,
  ADD_MEDIA_FILES_TO_LIBRARY,
} from 'Actions/mediaLibrary';

const defaultState = {
  isVisible: false,
  showMediaButton: true,
  controlMedia: Map(),
  displayURLs: Map(),
};

const mediaLibrary = (state = Map(defaultState), action) => {
  switch (action.type) {
    case MEDIA_LIBRARY_CREATE:
      return state.withMutations(map => {
        map.set('externalLibrary', action.payload);
        map.set('showMediaButton', action.payload.enableStandalone());
      });
    case MEDIA_LIBRARY_OPEN: {
      const { controlID, forImage, privateUpload } = action.payload;
      const privateUploadChanged = state.get('privateUpload') !== privateUpload;
      if (privateUploadChanged) {
        return Map({
          isVisible: true,
          forImage,
          controlID,
          canInsert: !!controlID,
          privateUpload,
          controlMedia: Map(),
        });
      }
      return state.withMutations(map => {
        map.set('isVisible', true);
        map.set('forImage', forImage);
        map.set('controlID', controlID);
        map.set('canInsert', !!controlID);
        map.set('privateUpload', privateUpload);
      });
    }
    case MEDIA_LIBRARY_CLOSE:
      return state.set('isVisible', false);
    case MEDIA_INSERT: {
      const { mediaPath } = action.payload;
      const controlID = state.get('controlID');
      return state.withMutations(map => {
        map.setIn(['controlMedia', controlID], mediaPath);
      });
    }
    case MEDIA_REMOVE_INSERTED: {
      const controlID = action.payload.controlID;
      return state.setIn(['controlMedia', controlID], '');
    }
    case MEDIA_LOAD_REQUEST:
      return state.withMutations(map => {
        map.set('isLoading', true);
        map.set('isPaginating', action.payload.page > 1);
      });
    case MEDIA_LOAD_SUCCESS: {
      const {
        files = [],
        page,
        canPaginate,
        dynamicSearch,
        dynamicSearchQuery,
        privateUpload,
      } = action.payload;
      const privateUploadChanged = state.get('privateUpload') !== privateUpload;

      if (privateUploadChanged) {
        return state;
      }

      const filesWithKeys = files.map(file => ({ ...file, key: uuid() }));
      return state.withMutations(map => {
        map.set('isLoading', false);
        map.set('isPaginating', false);
        map.set('page', page);
        map.set('hasNextPage', canPaginate && files.length > 0);
        map.set('dynamicSearch', dynamicSearch);
        map.set('dynamicSearchQuery', dynamicSearchQuery);
        map.set('dynamicSearchActive', !!dynamicSearchQuery);
        if (page && page > 1) {
          const updatedFiles = map.get('files').concat(filesWithKeys);
          map.set('files', updatedFiles);
        } else {
          map.set('files', filesWithKeys);
        }
      });
    }
    case MEDIA_LOAD_FAILURE: {
      const privateUploadChanged = state.get('privateUpload') !== action.payload.privateUpload;
      if (privateUploadChanged) {
        return state;
      }
      return state.set('isLoading', false);
    }
    case MEDIA_PERSIST_REQUEST:
      return state.set('isPersisting', true);
    case MEDIA_PERSIST_SUCCESS: {
      const { file, privateUpload } = action.payload;
      const privateUploadChanged = state.get('privateUpload') !== privateUpload;
      if (privateUploadChanged) {
        return state;
      }
      return state.withMutations(map => {
        const fileWithKey = { ...file, key: uuid() };
        const updatedFiles = [fileWithKey, ...map.get('files')];
        map.set('files', updatedFiles);
        map.set('isPersisting', false);
      });
    }
    case ADD_MEDIA_FILES_TO_LIBRARY: {
      const { mediaFiles } = action.payload;
      let updatedFiles = differenceBy(state.get('files'), mediaFiles, 'path');
      updatedFiles = [...mediaFiles.map(file => ({ ...file, key: uuid() })), ...updatedFiles];
      return state.set('files', updatedFiles);
    }
    case MEDIA_PERSIST_FAILURE: {
      const privateUploadChanged = state.get('privateUpload') !== action.payload.privateUpload;
      if (privateUploadChanged) {
        return state;
      }
      return state.set('isPersisting', false);
    }
    case MEDIA_DELETE_REQUEST:
      return state.set('isDeleting', true);
    case MEDIA_DELETE_SUCCESS: {
      const { id, key, privateUpload } = action.payload.file;
      const privateUploadChanged = state.get('privateUpload') !== privateUpload;
      if (privateUploadChanged) {
        return state;
      }
      return state.withMutations(map => {
        const updatedFiles = map
          .get('files')
          .filter(file => (key ? file.key !== key : file.id !== id));
        map.set('files', updatedFiles);
        map.deleteIn(['displayURLs', id]);
        map.set('isDeleting', false);
      });
    }
    case MEDIA_DELETE_FAILURE: {
      const privateUploadChanged = state.get('privateUpload') !== action.payload.privateUpload;
      if (privateUploadChanged) {
        return state;
      }
      return state.set('isDeleting', false);
    }

    case MEDIA_DISPLAY_URL_REQUEST:
      return state.setIn(['displayURLs', action.payload.key, 'isFetching'], true);

    case MEDIA_DISPLAY_URL_SUCCESS: {
      const displayURLPath = ['displayURLs', action.payload.key];
      return state
        .setIn([...displayURLPath, 'isFetching'], false)
        .setIn([...displayURLPath, 'url'], action.payload.url);
    }

    case MEDIA_DISPLAY_URL_FAILURE: {
      const displayURLPath = ['displayURLs', action.payload.key];
      return (
        state
          .setIn([...displayURLPath, 'isFetching'], false)
          // make sure that err is set so the CMS won't attempt to load
          // the image again
          .setIn([...displayURLPath, 'err'], action.payload.err || true)
          .deleteIn([...displayURLPath, 'url'])
      );
    }
    default:
      return state;
  }
};

export default mediaLibrary;