// Copyright 2011 Software Freedom Conservancy
// 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.

#include "CommandLineArguments.h"

CommandLineArguments::CommandLineArguments(int argc, _TCHAR* argv[]) {
  this->ParseArguments(argc, argv);
}

CommandLineArguments::~CommandLineArguments(void) {
}

std::string CommandLineArguments::GetValue(std::string arg_name,
                                           std::string default_value) {
  std::map<std::string, std::string>::const_iterator it = 
      this->args_map_.find(arg_name);
  if (it != this->args_map_.end()) {
    return it->second;
  }
  return default_value;
}

void CommandLineArguments::ParseArguments(int argc, _TCHAR* argv[]) {
  this->is_help_requested_ = false;
  std::map<std::string, std::string> args;
  for (int i = 1; i < argc; ++i) {
    std::wstring raw_arg(argv[i]);
    int switch_delimiter_length = GetSwitchDelimiterLength(raw_arg);
    std::wstring arg = raw_arg.substr(switch_delimiter_length);
    size_t equal_pos = arg.find(L"=");
    std::string arg_name = "";
    std::string arg_value = "";
    if (equal_pos != std::string::npos && equal_pos > 0) { 
      arg_name = CW2A(arg.substr(0, equal_pos).c_str(), CP_UTF8);
      arg_value = CW2A(arg.substr(equal_pos + 1).c_str(), CP_UTF8);
    } else {
      arg_name = CW2A(arg.c_str(), CP_UTF8);
    }

    // coerce all argument names to lowercase, making argument names
    // case-insensitive.
    std::transform(arg_name.begin(), arg_name.end(), arg_name.begin(), tolower);
    if (arg_name == "?" || arg_name == "h" || arg_name == "help") {
      this->is_help_requested_ = true;
    }
    this->args_map_[arg_name] = arg_value;
  }
}

int CommandLineArguments::GetSwitchDelimiterLength(std::wstring arg) {
  if (arg.find(L"--") == 0) {
    return 2;
  } else if (arg.find(L"-") == 0 || arg.find(L"/") == 0) {
    return 1;
  }

  return 0;
}