// Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cros-disks/process.h"

#include <base/logging.h>

using std::string;
using std::vector;

namespace cros_disks {

// static
const pid_t Process::kInvalidProcessId = -1;

Process::Process() : pid_(kInvalidProcessId) {
}

Process::~Process() {
}

void Process::AddArgument(const string& argument) {
  arguments_.push_back(argument);
}

char** Process::GetArguments() {
  if (!arguments_array_.get())
    BuildArgumentsArray();

  return arguments_array_.get();
}

bool Process::BuildArgumentsArray() {
  // The following code creates a writable copy of argument strings.
  size_t num_arguments = arguments_.size();
  if (num_arguments == 0)
    return false;

  size_t arguments_buffer_size = 0;
  for (size_t i = 0; i < num_arguments; ++i) {
    arguments_buffer_size += arguments_[i].size() + 1;
  }

  arguments_buffer_.reset(new(std::nothrow) char[arguments_buffer_size]);
  CHECK(arguments_buffer_.get()) << "Failed to allocate arguments buffer";

  arguments_array_.reset(new(std::nothrow) char*[num_arguments + 1]);
  CHECK(arguments_array_.get()) << "Failed to allocate arguments array";

  char* buffer_pointer = arguments_buffer_.get();
  for (size_t i = 0; i < num_arguments; ++i) {
    arguments_array_[i] = buffer_pointer;
    size_t argument_size = arguments_[i].size();
    arguments_[i].copy(buffer_pointer, argument_size);
    buffer_pointer[argument_size] = '\0';
    buffer_pointer += argument_size + 1;
  }
  arguments_array_[num_arguments] = NULL;
  return true;
}

}  // namespace cros_disks