RestMiddleware.java

package br.com.catbag.gifreduxsample.middlewares;

import android.content.Context;

import com.umaplay.fluxxan.Action;
import com.umaplay.fluxxan.impl.BaseMiddleware;

import java.io.File;
import java.util.HashMap;
import java.util.Map;

import br.com.catbag.gifreduxsample.actions.PayloadParams;
import br.com.catbag.gifreduxsample.asyncs.data.DataManager;
import br.com.catbag.gifreduxsample.asyncs.data.net.downloader.FileDownloader;
import br.com.catbag.gifreduxsample.models.AppState;
import br.com.catbag.gifreduxsample.models.Gif;

import static br.com.catbag.gifreduxsample.actions.GifActionCreator.GIF_DOWNLOAD_FAILURE;
import static br.com.catbag.gifreduxsample.actions.GifActionCreator.GIF_DOWNLOAD_START;
import static br.com.catbag.gifreduxsample.actions.GifActionCreator.GIF_DOWNLOAD_SUCCESS;
import static br.com.catbag.gifreduxsample.actions.GifListActionCreator.GIF_LIST_FETCHING;
import static br.com.catbag.gifreduxsample.actions.GifListActionCreator.GIF_LIST_UPDATED;

/**
 Copyright 26/10/2016
 Felipe Piñeiro (fpbitencourt@gmail.com),
 Nilton Vasques (nilton.vasques@gmail.com) and
 Raul Abreu (raulccabreu@gmail.com)

 Be free to ask for help, email us!

 Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 in compliance with the License. You may obtain a copy of the License at
 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software distributed under the License
 is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 implied. See the License for the specific language governing permissions and limitations under
 the License.
 **/

public class RestMiddleware extends BaseMiddleware<AppState> {
    private final Context mContext;
    private final FileDownloader mFileDownloader;
    private DataManager mDataManager;

    public RestMiddleware(Context context, DataManager dataManager, FileDownloader fileDownloader) {
        super();
        mContext = context;
        mDataManager = dataManager;
        mFileDownloader = fileDownloader;
    }

    @Override
    public void intercept(AppState appState, Action action) throws Exception {
        switch(action.Type) {
            case GIF_DOWNLOAD_START:
                downloadGif(appState, action);
                break;
            case GIF_LIST_FETCHING:
                fetchGifs(appState);
                break;
            default:
                break;
        }
    }

    private void fetchGifs(AppState appState) {
        if (appState.getHasMoreGifs()) {
            mDataManager.fetchGifs((gifs, hasMore) -> {
                Map<String, Object> params = new HashMap<>();
                params.put(PayloadParams.PARAM_GIFS, gifs);
                params.put(PayloadParams.PARAM_HAS_MORE, hasMore);
                mDispatcher.dispatch(new Action(GIF_LIST_UPDATED, params));
            });
        }
    }

    private void downloadGif(AppState appState, Action action) {
        Gif gif = appState.getGifs().get(action.Payload.toString());
        String pathToSave = mContext.getExternalFilesDir(null) + File.separator
                + gif.getUuid() + ".gif";

        mFileDownloader.download(gif.getUrl(), pathToSave,
                () -> {
                    Map<String, Object> params = new HashMap<>();
                    params.put(PayloadParams.PARAM_UUID, gif.getUuid());
                    params.put(PayloadParams.PARAM_PATH, pathToSave);
                    mDispatcher.dispatch(new Action(GIF_DOWNLOAD_SUCCESS, params));
                },
                e -> mDispatcher.dispatch(new Action(GIF_DOWNLOAD_FAILURE, gif.getUuid())));
    }
}