#include "cmSystemTools.h"

class CompileCommandParser
{
public:
  class CommandType : public std::map<std::string, std::string>
  {
  public:
    std::string const& at(std::string const& k) const
    {
      const_iterator i = this->find(k);
      if (i != this->end()) {
        return i->second;
      }
      static std::string emptyString;
      return emptyString;
    }
  };
  typedef std::vector<CommandType> TranslationUnitsType;

  CompileCommandParser(std::ifstream* input) { this->Input = input; }

  void Parse()
  {
    NextNonWhitespace();
    ParseTranslationUnits();
  }

  const TranslationUnitsType& GetTranslationUnits()
  {
    return this->TranslationUnits;
  }

private:
  void ParseTranslationUnits()
  {
    this->TranslationUnits = TranslationUnitsType();
    ExpectOrDie('[', "at start of compile command file\n");
    do {
      ParseTranslationUnit();
      this->TranslationUnits.push_back(this->Command);
    } while (Expect(','));
    ExpectOrDie(']', "at end of array");
  }

  void ParseTranslationUnit()
  {
    this->Command = CommandType();
    if (!Expect('{'))
      return;
    if (Expect('}'))
      return;
    do {
      ParseString();
      std::string name = this->String;
      ExpectOrDie(':', "between name and value");
      ParseString();
      std::string value = this->String;
      this->Command[name] = value;
    } while (Expect(','));
    ExpectOrDie('}', "at end of object");
  }

  void ParseString()
  {
    this->String = "";
    if (!Expect('"'))
      return;
    while (!Expect('"')) {
      Expect('\\');
      this->String.append(1, C);
      Next();
    }
  }

  bool Expect(char c)
  {
    if (this->C == c) {
      NextNonWhitespace();
      return true;
    }
    return false;
  }

  void ExpectOrDie(char c, const std::string& message)
  {
    if (!Expect(c))
      ErrorExit(std::string("'") + c + "' expected " + message + ".");
  }

  void NextNonWhitespace()
  {
    do {
      Next();
    } while (IsWhitespace());
  }

  void Next()
  {
    this->C = char(Input->get());
    if (this->Input->bad())
      ErrorExit("Unexpected end of file.");
  }

  void ErrorExit(const std::string& message)
  {
    std::cout << "ERROR: " << message;
    exit(1);
  }

  bool IsWhitespace()
  {
    return (this->C == ' ' || this->C == '\t' || this->C == '\n' ||
            this->C == '\r');
  }

  char C;
  TranslationUnitsType TranslationUnits;
  CommandType Command;
  std::string String;
  std::ifstream* Input;
};

int main()
{
  std::ifstream file("compile_commands.json");
  CompileCommandParser parser(&file);
  parser.Parse();
  for (CompileCommandParser::TranslationUnitsType::const_iterator
         it = parser.GetTranslationUnits().begin(),
         end = parser.GetTranslationUnits().end();
       it != end; ++it) {
    std::vector<std::string> command;
    cmSystemTools::ParseUnixCommandLine(it->at("command").c_str(), command);
    if (!cmSystemTools::RunSingleCommand(command, 0, 0, 0,
                                         it->at("directory").c_str())) {
      std::cout << "ERROR: Failed to run command \"" << command[0] << "\""
                << std::endl;
      exit(1);
    }
  }
  return 0;
}
