/**
 * Copyright 2012-2020 The Feign Authors
 *
 * 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.jackson;

import com.fasterxml.jackson.databind.ObjectMapper;
import feign.Request;
import feign.Request.HttpMethod;
import feign.Response;
import feign.Util;
import feign.codec.DecodeException;
import feign.jackson.JacksonIteratorDecoder.JacksonIterator;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.NoSuchElementException;
import java.util.concurrent.atomic.AtomicBoolean;
import static feign.Util.UTF_8;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.hamcrest.core.Is.isA;

@SuppressWarnings("deprecation")
public class JacksonIteratorTest {

  @Rule
  public final ExpectedException thrown = ExpectedException.none();

  @Test
  public void shouldDecodePrimitiveArrays() throws IOException {
    assertThat(iterator(Integer.class, "[0,1,2,3]")).containsExactly(0, 1, 2, 3);
  }

  @Test
  public void shouldNotSkipElementsOnHasNext() throws IOException {
    JacksonIterator<Integer> iterator = iterator(Integer.class, "[0]");
    assertThat(iterator.hasNext()).isTrue();
    assertThat(iterator.hasNext()).isTrue();
    assertThat(iterator.next()).isEqualTo(0);
    assertThat(iterator.hasNext()).isFalse();
  }

  @Test
  public void hasNextIsNotMandatory() throws IOException {
    JacksonIterator<Integer> iterator = iterator(Integer.class, "[0]");
    assertThat(iterator.next()).isEqualTo(0);
    assertThat(iterator.hasNext()).isFalse();
  }

  @Test
  public void expectExceptionOnNoElements() throws IOException {
    JacksonIterator<Integer> iterator = iterator(Integer.class, "[0]");
    assertThat(iterator.next()).isEqualTo(0);
    assertThatThrownBy(() -> iterator.next())
        .hasMessage(null)
        .isInstanceOf(NoSuchElementException.class);
  }

  @Test
  public void shouldDecodeObjects() throws IOException {
    assertThat(iterator(User.class, "[{\"login\":\"bob\"},{\"login\":\"joe\"}]"))
        .containsExactly(new User("bob"), new User("joe"));
  }

  @Test
  public void malformedObjectThrowsDecodeException() throws IOException {
    thrown.expect(DecodeException.class);
    thrown.expectCause(isA(IOException.class));

    assertThat(iterator(User.class, "[{\"login\":\"bob\"},{\"login\":\"joe..."))
        .containsOnly(new User("bob"));
  }

  @Test
  public void emptyBodyDecodesToEmptyIterator() throws IOException {
    assertThat(iterator(String.class, "")).isEmpty();
  }

  @Test
  public void unmodifiable() throws IOException {
    thrown.expect(UnsupportedOperationException.class);

    JacksonIterator<String> it = iterator(String.class, "[\"test\"]");

    assertThat(it).containsExactly("test");
    it.remove();
  }

  @Test
  public void responseIsClosedAfterIteration() throws IOException {
    final AtomicBoolean closed = new AtomicBoolean();

    byte[] jsonBytes = "[false, true]".getBytes(UTF_8);
    InputStream inputStream = new ByteArrayInputStream(jsonBytes) {
      @Override
      public void close() throws IOException {
        closed.set(true);
        super.close();
      }
    };
    Response response = Response.builder()
        .status(200)
        .reason("OK")
        .request(
            Request.create(HttpMethod.GET, "/api", Collections.emptyMap(), null, Util.UTF_8, null))
        .headers(Collections.emptyMap())
        .body(inputStream, jsonBytes.length)
        .build();

    assertThat(iterator(Boolean.class, response)).hasSize(2);
    assertThat(closed.get()).isTrue();
  }

  @Test
  public void responseIsClosedOnParseError() throws IOException {
    final AtomicBoolean closed = new AtomicBoolean();

    byte[] jsonBytes = "[error".getBytes(UTF_8);
    InputStream inputStream = new ByteArrayInputStream(jsonBytes) {
      @Override
      public void close() throws IOException {
        closed.set(true);
        super.close();
      }
    };
    Response response = Response.builder()
        .status(200)
        .reason("OK")
        .request(
            Request.create(HttpMethod.GET, "/api", Collections.emptyMap(), null, Util.UTF_8, null))
        .headers(Collections.emptyMap())
        .body(inputStream, jsonBytes.length)
        .build();

    try {
      thrown.expect(DecodeException.class);
      assertThat(iterator(Boolean.class, response)).hasSize(1);
    } finally {
      assertThat(closed.get()).isTrue();
    }
  }

  static class User extends LinkedHashMap<String, Object> {

    private static final long serialVersionUID = 1L;

    User() {
      // for reflective instantiation.
    }

    User(String login) {
      put("login", login);
    }
  }

  <T> JacksonIterator<T> iterator(Class<T> type, String json) throws IOException {
    Response response = Response.builder()
        .status(200)
        .reason("OK")
        .request(
            Request.create(HttpMethod.GET, "/api", Collections.emptyMap(), null, Util.UTF_8, null))
        .headers(Collections.emptyMap())
        .body(json, UTF_8)
        .build();
    return iterator(type, response);
  }

  <T> JacksonIterator<T> iterator(Class<T> type, Response response) throws IOException {
    return new JacksonIterator<T>(type.getGenericSuperclass(), new ObjectMapper(),
        response, response.body().asReader(Util.UTF_8));
  }

}