/*
 * Copyright 2013 Netflix, Inc.
 *
 * 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 feign.gson;

import com.google.gson.reflect.TypeToken;
import dagger.Module;
import dagger.ObjectGraph;
import feign.Observer;
import feign.codec.Decoder;
import feign.codec.Encoder;
import feign.codec.IncrementalDecoder;
import org.testng.annotations.Test;

import javax.inject.Inject;
import java.io.StringReader;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;

import static org.testng.Assert.assertEquals;
import static org.testng.Assert.fail;

@Test
public class GsonModuleTest {

  @Test public void providesEncoderDecoderAndIncrementalDecoder() throws Exception {
    @Module(includes = GsonModule.class, injects = SetBindings.class) class SetBindings {
      @Inject Set<Encoder> encoders;
      @Inject Set<Decoder> decoders;
      @Inject Set<IncrementalDecoder> incrementalDecoders;
    }

    SetBindings bindings = new SetBindings();
    ObjectGraph.create(bindings).inject(bindings);

    assertEquals(bindings.encoders.size(), 1);
    assertEquals(bindings.encoders.iterator().next().getClass(), GsonModule.GsonCodec.class);
    assertEquals(bindings.decoders.size(), 1);
    assertEquals(bindings.decoders.iterator().next().getClass(), GsonModule.GsonCodec.class);
    assertEquals(bindings.incrementalDecoders.size(), 1);
    assertEquals(bindings.incrementalDecoders.iterator().next().getClass(), GsonModule.GsonCodec.class);
  }

  @Test public void encodesMapObjectNumericalValuesAsInteger() throws Exception {
    @Module(includes = GsonModule.class, injects = SetBindings.class) class SetBindings {
      @Inject Set<Encoder> encoders;
    }

    SetBindings bindings = new SetBindings();
    ObjectGraph.create(bindings).inject(bindings);

    Map<String, Object> map = new LinkedHashMap<String, Object>();
    map.put("foo", 1);

    assertEquals(Encoder.Text.class.cast(bindings.encoders.iterator().next()).encode(map), ""//
        + "{\n" //
        + "  \"foo\": 1\n" //
        + "}");
  }

  @Test public void encodesFormParams() throws Exception {
    @Module(includes = GsonModule.class, injects = SetBindings.class) class SetBindings {
      @Inject Set<Encoder> encoders;
    }

    SetBindings bindings = new SetBindings();
    ObjectGraph.create(bindings).inject(bindings);

    Map<String, Object> form = new LinkedHashMap<String, Object>();
    form.put("foo", 1);
    form.put("bar", Arrays.asList(2, 3));

    assertEquals(Encoder.Text.class.cast(bindings.encoders.iterator().next()).encode(form), ""//
        + "{\n" //
        + "  \"foo\": 1,\n" //
        + "  \"bar\": [\n" //
        + "    2,\n" //
        + "    3\n" //
        + "  ]\n" //
        + "}");
  }

  static class Zone extends LinkedHashMap<String, Object> {
    Zone() {
      // for reflective instantiation.
    }

    Zone(String name) {
      this(name, null);
    }

    Zone(String name, String id) {
      put("name", name);
      if (id != null)
        put("id", id);
    }

    private static final long serialVersionUID = 1L;
  }

  @Test public void decodes() throws Exception {
    @Module(includes = GsonModule.class, injects = SetBindings.class) class SetBindings {
      @Inject Set<Decoder> decoders;
    }

    SetBindings bindings = new SetBindings();
    ObjectGraph.create(bindings).inject(bindings);

    List<Zone> zones = new LinkedList<Zone>();
    zones.add(new Zone("denominator.io."));
    zones.add(new Zone("denominator.io.", "ABCD"));

    assertEquals(Decoder.TextStream.class.cast(bindings.decoders.iterator().next())
        .decode(new StringReader(zonesJson), new TypeToken<List<Zone>>() {
        }.getType()), zones);
  }

  @Test public void decodesIncrementally() throws Exception {
    @Module(includes = GsonModule.class, injects = SetBindings.class) class SetBindings {
      @Inject Set<IncrementalDecoder> decoders;
    }

    SetBindings bindings = new SetBindings();
    ObjectGraph.create(bindings).inject(bindings);

    final List<Zone> zones = new LinkedList<Zone>();
    zones.add(new Zone("denominator.io."));
    zones.add(new Zone("denominator.io.", "ABCD"));

    final AtomicInteger index = new AtomicInteger(0);

    Observer<Zone> zoneCallback = new Observer<Zone>() {

      @Override public void onNext(Zone element) {
        assertEquals(element, zones.get(index.getAndIncrement()));
      }

      @Override public void onSuccess() {
        // decoder shouldn't call onSuccess
        fail();
      }

      @Override public void onFailure(Throwable cause) {
        // decoder shouldn't call onFailure
        fail();
      }
    };

    IncrementalDecoder.TextStream.class.cast(bindings.decoders.iterator().next())
        .decode(new StringReader(zonesJson), Zone.class, zoneCallback, new AtomicBoolean(true));

    assertEquals(index.get(), 2);
  }

  private String zonesJson = ""//
      + "[\n"//
      + "  {\n"//
      + "    \"name\": \"denominator.io.\"\n"//
      + "  },\n"//
      + "  {\n"//
      + "    \"name\": \"denominator.io.\",\n"//
      + "    \"id\": \"ABCD\"\n"//
      + "  }\n"//
      + "]\n";
}