AlgoliaClient.java

/*
 * Copyright (c) 2015 Ha Duy Trung
 *
 * 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.
 */

package io.github.hidroh.materialistic.data;

import android.content.Context;
import android.support.annotation.Keep;
import android.support.annotation.NonNull;
import android.text.format.DateUtils;

import java.io.IOException;

import javax.inject.Inject;
import javax.inject.Named;

import io.github.hidroh.materialistic.ActivityModule;
import io.github.hidroh.materialistic.Preferences;
import io.github.hidroh.materialistic.annotation.Synthetic;
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;
import rx.Observable;
import rx.android.schedulers.AndroidSchedulers;

public class AlgoliaClient implements ItemManager {

    public static boolean sSortByTime = true;
    public static final String HOST = "hn.algolia.com";
    private static final String BASE_API_URL = "https://" + HOST + "/api/v1/";
    static final String MIN_CREATED_AT = "created_at_i>";
    RestService mRestService;
    @Inject @Named(ActivityModule.HN) ItemManager mHackerNewsClient;

    @Inject
    public AlgoliaClient(Context context, RestServiceFactory factory) {
        mRestService = factory.rxEnabled(true).create(BASE_API_URL, RestService.class);
        sSortByTime = Preferences.isSortByRecent(context);
    }

    @Override
    public void getStories(String filter, @CacheMode int cacheMode,
                           final ResponseListener<Item[]> listener) {
        if (listener == null) {
            return;
        }
        search(filter)
                .map(this::toItems)
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(listener::onResponse,
                        t -> listener.onError(t != null ? t.getMessage() : ""));
    }

    @Override
    public void getItem(String itemId, @CacheMode int cacheMode, ResponseListener<Item> listener) {
        mHackerNewsClient.getItem(itemId, cacheMode, listener);
    }

    @Override
    public Item[] getStories(String filter, @CacheMode int cacheMode) {
        long timestamp = System.currentTimeMillis() - DateUtils.DAY_IN_MILLIS; // since yesterday
        try {
            return toItems(mRestService.search(filter, MIN_CREATED_AT + timestamp / 1000)
                    .execute()
                    .body());
        } catch (IOException e) {
            return new Item[0];
        }
    }

    @Override
    public Item getItem(String itemId, @CacheMode int cacheMode) {
        return mHackerNewsClient.getItem(itemId, cacheMode);
    }

    protected Observable<AlgoliaHits> search(String filter) {
        // TODO add ETag header
        return sSortByTime ? mRestService.searchByDate(filter) : mRestService.search(filter);
    }

    @NonNull
    private Item[] toItems(AlgoliaHits algoliaHits) {
        if (algoliaHits == null) {
            return new Item[0];
        }
        Hit[] hits = algoliaHits.hits;
        Item[] stories = new Item[hits == null ? 0 : hits.length];
        for (int i = 0; i < stories.length; i++) {
            //noinspection ConstantConditions
            HackerNewsItem item = new HackerNewsItem(
                    Long.parseLong(hits[i].objectID));
            item.rank = i + 1;
            stories[i] = item;
        }
        return stories;
    }

    interface RestService {
        @GET("search_by_date?hitsPerPage=100&tags=story&attributesToRetrieve=objectID&attributesToHighlight=none")
        Observable<AlgoliaHits> searchByDate(@Query("query") String query);

        @GET("search?hitsPerPage=100&tags=story&attributesToRetrieve=objectID&attributesToHighlight=none")
        Observable<AlgoliaHits> search(@Query("query") String query);

        @GET("search?hitsPerPage=100&tags=story&attributesToRetrieve=objectID&attributesToHighlight=none")
        Observable<AlgoliaHits> searchByMinTimestamp(@Query("numericFilters") String timestampSeconds);

        @GET("search?hitsPerPage=10&tags=story&attributesToRetrieve=objectID&attributesToHighlight=none")
        Call<AlgoliaHits> search(@Query("query") String query, @Query("numericFilters") String timestampSeconds);
    }

    static class AlgoliaHits {
        @Keep @Synthetic
        Hit[] hits;
    }

    static class Hit {
        @Keep @Synthetic
        String objectID;
    }
}