// Copyright (C) 2015 Ericsson
//
// 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 com.ericsson.gerrit.plugins.highavailability.forwarder.rest;

import static com.google.common.truth.Truth.assertThat;
import static org.mockito.Mockito.anyString;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import com.google.common.base.Joiner;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.AccountGroup;
import com.google.gerrit.server.events.Event;
import com.google.gson.GsonBuilder;

import com.ericsson.gerrit.plugins.highavailability.Configuration;
import com.ericsson.gerrit.plugins.highavailability.cache.Constants;
import com.ericsson.gerrit.plugins.highavailability.forwarder.rest.HttpResponseHandler.HttpResult;

import org.junit.Test;

import java.io.IOException;

import javax.net.ssl.SSLException;

public class RestForwarderTest {
  private static final String PLUGIN_NAME = "high-availability";
  private static final String EMPTY_MSG = "";
  private static final String ERROR_MSG = "Error";
  private static final String EXCEPTION_MSG = "Exception";
  private static final boolean SUCCESSFUL = true;
  private static final boolean FAILED = false;
  private static final boolean DO_NOT_THROW_EXCEPTION = false;
  private static final boolean THROW_EXCEPTION = true;

  private static final int MAX_TRIES = 3;
  private static final int RETRY_INTERVAL = 250;

  //Index
  private static final int CHANGE_NUMBER = 1;
  private static final String DELETE_OP = "delete";
  private static final String INDEX_OP = "index/change";

  //Evict cache
  private static final String EMPTY_JSON = "{}";
  private static final String EMPTY_JSON2 = "\"{}\"";
  private static final String ID_JSON = "{\"id\":0}";

  private RestForwarder restForwarder;

  @Test
  public void testIndexChangeOK() throws Exception {
    setUpMocksForIndex(INDEX_OP, SUCCESSFUL, EMPTY_MSG, DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.indexChange(CHANGE_NUMBER)).isTrue();
  }

  @Test
  public void testIndexChangeFailed() throws Exception {
    setUpMocksForIndex(INDEX_OP, FAILED, ERROR_MSG, DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.indexChange(CHANGE_NUMBER)).isFalse();
  }

  @Test
  public void testIndexChangeThrowsException() throws Exception {
    setUpMocksForIndex(INDEX_OP, FAILED, EXCEPTION_MSG, THROW_EXCEPTION);
    assertThat(restForwarder.indexChange(CHANGE_NUMBER)).isFalse();
  }

  @Test
  public void testChangeDeletedFromIndexOK() throws Exception {
    setUpMocksForIndex(DELETE_OP, SUCCESSFUL, EMPTY_MSG,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.deleteChangeFromIndex(CHANGE_NUMBER)).isTrue();
  }

  @Test
  public void testChangeDeletedFromIndexFailed() throws Exception {
    setUpMocksForIndex(DELETE_OP, FAILED, ERROR_MSG, DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.deleteChangeFromIndex(CHANGE_NUMBER)).isFalse();
  }

  @Test
  public void testChangeDeletedFromThrowsException() throws Exception {
    setUpMocksForIndex(DELETE_OP, FAILED, EXCEPTION_MSG, THROW_EXCEPTION);
    assertThat(restForwarder.deleteChangeFromIndex(CHANGE_NUMBER)).isFalse();
  }

  private void setUpMocksForIndex(String operation,
      boolean isOperationSuccessful, String msg, boolean exception)
      throws Exception {
    String request =
        Joiner.on("/").join("/plugins", PLUGIN_NAME, INDEX_OP, CHANGE_NUMBER);
    HttpSession httpSession = mock(HttpSession.class);
    if (exception) {
      if (operation.equals(INDEX_OP)) {
        doThrow(new IOException()).when(httpSession).post(request);
      } else {
        doThrow(new IOException()).when(httpSession).delete(request);
      }
    } else {
      HttpResult result = new HttpResult(isOperationSuccessful, msg);
      if (operation.equals(INDEX_OP)) {
        when(httpSession.post(request)).thenReturn(result);
      } else {
        when(httpSession.delete(request)).thenReturn(result);
      }
    }
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(MAX_TRIES);
    when(cfg.getRetryInterval()).thenReturn(RETRY_INTERVAL);
    restForwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
  }

  @Test
  public void testEventSentOK() throws Exception {
    Event event = setUpMocksForEvent(SUCCESSFUL, EMPTY_MSG, DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.send(event)).isTrue();
  }

  @Test
  public void testEventSentFailed() throws Exception {
    Event event = setUpMocksForEvent(FAILED, ERROR_MSG, DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.send(event)).isFalse();
  }

  @Test
  public void testEventSentThrowsException() throws Exception {
    Event event = setUpMocksForEvent(FAILED, EXCEPTION_MSG, THROW_EXCEPTION);
    assertThat(restForwarder.send(event)).isFalse();
  }

  private Event setUpMocksForEvent(boolean isOperationSuccessful, String msg,
      boolean exception) throws Exception {
    Event event = new EventTest();
    String content = new GsonBuilder().create().toJson(event);
    HttpSession httpSession = mock(HttpSession.class);
    String request = Joiner.on("/").join("/plugins", PLUGIN_NAME, "event");
    if (exception) {
      doThrow(new IOException()).when(httpSession).post(request, content);
    } else {
      HttpResult result = new HttpResult(isOperationSuccessful, msg);
      when(httpSession.post(request, content)).thenReturn(result);
    }
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(MAX_TRIES);
    when(cfg.getRetryInterval()).thenReturn(RETRY_INTERVAL);
    restForwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
    return event;
  }

  private class EventTest extends Event {
    public EventTest() {
      super("test-event");
    }
  }

  @Test
  public void testEvictCacheOK() throws Exception {
    setupMocksForCache(Constants.PROJECTS, EMPTY_JSON2, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.PROJECTS, EMPTY_JSON)).isTrue();
  }

  @Test
  public void testEvictAccountsOK() throws Exception {
    setupMocksForCache(Constants.ACCOUNTS, ID_JSON, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.ACCOUNTS, mock(Account.Id.class)))
        .isTrue();
  }

  @Test
  public void testEvictGroupsOK() throws Exception {
    setupMocksForCache(Constants.GROUPS, ID_JSON, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(
        restForwarder.evict(Constants.GROUPS, mock(AccountGroup.Id.class)))
            .isTrue();
  }

  @Test
  public void testEvictGroupsByIncludeOK() throws Exception {
    setupMocksForCache(Constants.GROUPS_BYINCLUDE, EMPTY_JSON, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.GROUPS_BYINCLUDE,
        mock(AccountGroup.UUID.class))).isTrue();
  }

  @Test
  public void testEvictGroupsMembersOK() throws Exception {
    setupMocksForCache(Constants.GROUPS_MEMBERS, EMPTY_JSON, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.GROUPS_MEMBERS,
        mock(AccountGroup.UUID.class))).isTrue();
  }

  @Test
  public void testEvictProjectListOK() throws Exception {
    setupMocksForCache(Constants.PROJECT_LIST, EMPTY_JSON, SUCCESSFUL,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.PROJECT_LIST, new Object()))
        .isTrue();
  }

  @Test
  public void testEvictCacheFailed() throws Exception {
    setupMocksForCache(Constants.PROJECTS, EMPTY_JSON2, FAILED,
        DO_NOT_THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.PROJECTS, EMPTY_JSON)).isFalse();
  }

  @Test
  public void testEvictCacheThrowsException() throws Exception {
    setupMocksForCache(Constants.PROJECTS, EMPTY_JSON2, FAILED,
        THROW_EXCEPTION);
    assertThat(restForwarder.evict(Constants.PROJECTS, EMPTY_JSON)).isFalse();
  }

  private void setupMocksForCache(String cacheName, String json,
      boolean isOperationSuccessful, boolean exception) throws IOException {
    String request =
        Joiner.on("/").join("/plugins", PLUGIN_NAME, "cache", cacheName);
    HttpSession httpSession = mock(HttpSession.class);
    if (exception) {
      doThrow(new IOException()).when(httpSession).post(request, json);
    } else {
      HttpResult result = new HttpResult(isOperationSuccessful, "Error");
      when(httpSession.post(request, json)).thenReturn(result);
    }
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(MAX_TRIES);
    when(cfg.getRetryInterval()).thenReturn(RETRY_INTERVAL);
    restForwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
  }

  @Test
  public void testRetryOnErrorThenSuccess() throws IOException {
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(3);
    when(cfg.getRetryInterval()).thenReturn(10);

    HttpSession httpSession = mock(HttpSession.class);
    when(httpSession.post(anyString(), anyString()))
        .thenReturn(new HttpResult(false, "Error"))
        .thenReturn(new HttpResult(false, "Error"))
        .thenReturn(new HttpResult(true, "Success"));

    RestForwarder forwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
    assertThat(forwarder.evict(Constants.PROJECT_LIST, new Object()))
        .isTrue();
  }

  @Test
  public void testRetryOnIoExceptionThenSuccess() throws IOException {
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(3);
    when(cfg.getRetryInterval()).thenReturn(10);

    HttpSession httpSession = mock(HttpSession.class);
    when(httpSession.post(anyString(), anyString()))
        .thenThrow(new IOException())
        .thenThrow(new IOException())
        .thenReturn(new HttpResult(true, "Success"));

    RestForwarder forwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
    assertThat(forwarder.evict(Constants.PROJECT_LIST, new Object()))
        .isTrue();
  }

  @Test
  public void testNoRetryAfterNonRecoverableException() throws IOException {
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(3);
    when(cfg.getRetryInterval()).thenReturn(10);

    HttpSession httpSession = mock(HttpSession.class);
    when(httpSession.post(anyString(), anyString()))
        .thenThrow(new SSLException("Non Recoverable"))
        .thenReturn(new HttpResult(true, "Success"));

    RestForwarder forwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
    assertThat(forwarder.evict(Constants.PROJECT_LIST, new Object()))
        .isFalse();
  }

  @Test
  public void testFailureAfterMaxTries() throws IOException {
    Configuration cfg = mock(Configuration.class);
    when(cfg.getMaxTries()).thenReturn(3);
    when(cfg.getRetryInterval()).thenReturn(10);

    HttpSession httpSession = mock(HttpSession.class);
    when(httpSession.post(anyString(), anyString()))
        .thenReturn(new HttpResult(false, "Error"))
        .thenReturn(new HttpResult(false, "Error"))
        .thenReturn(new HttpResult(false, "Error"));

    RestForwarder forwarder = new RestForwarder(httpSession, PLUGIN_NAME, cfg);
    assertThat(forwarder.evict(Constants.PROJECT_LIST, new Object()))
        .isFalse();
  }
}