/*
 *
 * Copyright 2015, Google Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

/*
  A command line tool to talk to any grpc server.
  Example of talking to grpc interop server:
  1. Prepare request binary file:
    a. create a text file input.txt, containing the following:
        response_size: 10
        payload: {
          body: "hello world"
        }
    b. under grpc/ run
        protoc --proto_path=test/cpp/interop/ \
        --encode=grpc.testing.SimpleRequest test/cpp/interop/messages.proto \
        < input.txt > input.bin
  2. Start a server
    make interop_server && bins/opt/interop_server --port=50051
  3. Run the tool
    make grpc_cli && bins/opt/grpc_cli call localhost:50051 \
    /grpc.testing.TestService/UnaryCall --enable_ssl=false \
    --input_binary_file=input.bin --output_binary_file=output.bin
  4. Decode response
    protoc --proto_path=test/cpp/interop/ \
    --decode=grpc.testing.SimpleResponse test/cpp/interop/messages.proto \
    < output.bin > output.txt
  5. Now the text form of response should be in output.txt
*/

#include <fstream>
#include <iostream>
#include <sstream>

#include <gflags/gflags.h>
#include "test/cpp/util/cli_call.h"
#include <grpc++/channel_arguments.h>
#include <grpc++/channel_interface.h>
#include <grpc++/create_channel.h>
#include <grpc++/credentials.h>

#include <grpc/grpc.h>

// In some distros, gflags is in the namespace google, and in some others,
// in gflags. This hack is enabling us to find both.
namespace google {}
namespace gflags {}
using namespace google;
using namespace gflags;

DEFINE_bool(enable_ssl, true, "Whether to use ssl/tls.");
DEFINE_bool(use_auth, false, "Whether to create default google credentials.");
DEFINE_string(input_binary_file, "",
              "Path to input file containing serialized request.");
DEFINE_string(output_binary_file, "output.bin",
              "Path to output file to write serialized response.");

int main(int argc, char** argv) {
  grpc_init();

  ParseCommandLineFlags(&argc, &argv, true);

  if (argc < 4 || grpc::string(argv[1]) != "call") {
    std::cout << "Usage: grpc_cli call server_host:port full_method_string\n"
              << "Example: grpc_cli call service.googleapis.com "
              << "/grpc.testing.TestService/UnaryCall "
              << "--input_binary_file=input.bin --output_binary_file=output.bin"
              << std::endl;
  }
  grpc::string server_address(argv[2]);
  // TODO(yangg) basic check of method string
  grpc::string method(argv[3]);

  if (FLAGS_input_binary_file.empty()) {
    std::cout << "Missing --input_binary_file for serialized request."
              << std::endl;
    return 1;
  }
  std::cout << "connecting to " << server_address << std::endl;

  std::ifstream input_file(FLAGS_input_binary_file,
                           std::ios::in | std::ios::binary);
  std::stringstream input_stream;
  input_stream << input_file.rdbuf();

  std::unique_ptr<grpc::Credentials> creds;
  if (!FLAGS_enable_ssl) {
    creds = grpc::InsecureCredentials();
  } else {
    if (FLAGS_use_auth) {
      creds = grpc::GoogleDefaultCredentials();
    } else {
      creds = grpc::SslCredentials(grpc::SslCredentialsOptions());
    }
  }
  std::shared_ptr<grpc::ChannelInterface> channel =
      grpc::CreateChannel(server_address, creds, grpc::ChannelArguments());

  grpc::string response;
  grpc::testing::CliCall::Call(channel, method, input_stream.str(), &response);
  if (!response.empty()) {
    std::ofstream output_file(FLAGS_output_binary_file,
                              std::ios::trunc | std::ios::binary);
    output_file << response;
  }

  channel.reset();
  grpc_shutdown();
  return 0;
}