/*
 * Copyright 2017 The gRPC 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 io.grpc.testing.integration;

import io.grpc.Grpc;
import io.grpc.ManagedChannelBuilder;
import io.grpc.TlsChannelCredentials;
import io.grpc.netty.NettyChannelBuilder;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Locale;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.logging.Handler;
import java.util.logging.LogRecord;
import java.util.logging.Logger;
import java.util.logging.SimpleFormatter;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.junit.Ignore;
import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

/**
 * This servlet communicates with {@code grpc-test.sandbox.googleapis.com}, which is a server
 * managed by the gRPC team. For more information, see
 * <a href="https://github.com/grpc/grpc/blob/master/doc/interop-test-descriptions.md">
 *   Interoperability Test Case Descriptions</a>.
 */
@SuppressWarnings("serial")
public final class NettyClientInteropServlet extends HttpServlet {
  private static final String INTEROP_TEST_ADDRESS = "grpc-test.sandbox.googleapis.com:443";

  private static final class LogEntryRecorder extends Handler {
    private Queue<LogRecord> loggedMessages = new ConcurrentLinkedQueue<>();

    @Override
    public void publish(LogRecord logRecord) {
      loggedMessages.add(logRecord);
    }

    @Override
    public void flush() {}

    @Override
    public void close() {}

    public String getLogOutput() {
      SimpleFormatter formatter = new SimpleFormatter();
      StringBuilder sb = new StringBuilder();
      for (LogRecord loggedMessage : loggedMessages) {
        sb.append(formatter.format(loggedMessage));
      }
      return sb.toString();
    }
  }

  @Override
  public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
    LogEntryRecorder handler = new LogEntryRecorder();
    Logger.getLogger("").addHandler(handler);
    try {
      doGetHelper(resp);
    } finally {
      Logger.getLogger("").removeHandler(handler);
    }
    resp.getWriter().append("=======================================\n")
        .append("Server side java.util.logging messages:\n")
        .append(handler.getLogOutput());
  }

  private void doGetHelper(HttpServletResponse resp) throws IOException {
    resp.setContentType("text/plain");
    PrintWriter writer = resp.getWriter();
    writer.println("Test invoked at: ");
    writer.println(new SimpleDateFormat("yyyy/MM/dd HH:mm:ss Z")
        .format(Calendar.getInstance().getTime()));

    Result result = new JUnitCore().run(Tester.class);
    if (result.wasSuccessful()) {
      resp.setStatus(200);
      writer.println(
          String.format(
              Locale.US,
              "PASS! Tests ran %d, tests ignored %d",
              result.getRunCount(),
              result.getIgnoreCount()));
    } else {
      resp.setStatus(500);
      writer.println(
          String.format(
              Locale.US,
              "FAILED! Tests ran %d, tests failed %d, tests ignored %d",
              result.getRunCount(),
              result.getFailureCount(),
              result.getIgnoreCount()));
      for (Failure failure : result.getFailures()) {
        writer.println("================================");
        writer.println(failure.getTestHeader());
        Throwable thrown = failure.getException();
        StringWriter stringWriter = new StringWriter();
        PrintWriter printWriter = new PrintWriter(stringWriter);
        thrown.printStackTrace(printWriter);
        writer.println(stringWriter);
      }
    }
  }

  public static final class Tester extends AbstractInteropTest {
    @Override
    protected ManagedChannelBuilder<?> createChannelBuilder() {
      ManagedChannelBuilder<?> builder =
          Grpc.newChannelBuilder(INTEROP_TEST_ADDRESS, TlsChannelCredentials.create())
              .maxInboundMessageSize(AbstractInteropTest.MAX_MESSAGE_SIZE);
      ((NettyChannelBuilder) builder)
          .flowControlWindow(AbstractInteropTest.TEST_FLOW_CONTROL_WINDOW);
      return builder;
    }

    @Override
    protected boolean metricsExpected() {
      // Server-side metrics won't be found because the server is running remotely.
      return false;
    }

    // grpc-test.sandbox.googleapis.com does not support these tests
    @Ignore
    @Override
    public void customMetadata() { }

    @Ignore
    @Override
    public void statusCodeAndMessage() { }

    @Ignore
    @Override
    public void exchangeMetadataUnaryCall() { }

    @Ignore
    @Override
    public void exchangeMetadataStreamingCall() { }

    @Ignore
    @Override
    public void specialStatusMessage() {}
  }
}
