text: /* lorina: C++ parsing library
   * Copyright (C) 2018-2021  EPFL
   *
   * Permission is hereby granted, free of charge, to any person
   * obtaining a copy of this software and associated documentation
   * files (the "Software"), to deal in the Software without
   * restriction, including without limitation the rights to use,
   * copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following
   * conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
   * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
   * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   */
  
  /*!
    \file diagnostics.hpp
    \brief Implements diagnostics.
  
    \author Heinz Riener
  */
  
  #pragma once
  
  #include <rang/rang.hpp>
  #include <map>
  #include <iostream>
  #include <cassert>
  
  namespace lorina
  {
  
  class diagnostic_builder;
  class diagnostic_engine;
  
  enum class diagnostic_level
  {
    ignore = 0,
    note,
    remark,
    warning,
    error,
    fatal,
  };
  
  /*! \brief A builder for diagnostics.
   *
   * An object that encapsulates a diagnostic.  The diagnostic may take
   * additional parameters and is finally issued at the end of its
   * life time.
   */
  class diagnostic_builder
  {
  public:
    /*! \brief Constructs a diagnostic builder.
     *
     * \param diag Diagnostic engine
     * \param level Severity level
     * \param message Diagnostic message
     */
    inline explicit diagnostic_builder( diagnostic_engine& diag, diagnostic_level level, const std::string& message );
  
    /*! \brief Destructs the diagnostic builder and issues the diagnostic. */
    inline ~diagnostic_builder();
  
    diagnostic_engine& _diag; /*!< diagnostic engine */
    diagnostic_level _level; /*!< diagnostic level */
    std::string _message; /*!< diagnostic message */
  }; /* diagnostic_builder */
  
  /*! \brief A diagnostic engine. */
  class diagnostic_engine
  {
  public:
    /*! \brief Creates a diagnostic builder.
     *
     * \param level Severity level
     * \param message Diagnostic message
     */
    virtual inline diagnostic_builder report( diagnostic_level level, const std::string& message );
  
    /*! \brief Emits a diagnostic message.
     *
     * \param level Severity level
     * \param message Diagnostic message
     */
    virtual inline void emit( diagnostic_level level, const std::string& message ) const;
  
  public:
    mutable unsigned number_of_diagnostics = 0; /*!< Number of diagnostics constructed via report */
  }; /* diagnostic_engine */
  
  diagnostic_builder::diagnostic_builder( diagnostic_engine& diag, diagnostic_level level, const std::string& message )
      : _diag( diag ), _level( level ), _message( message )
  {
  }
  
  diagnostic_builder::~diagnostic_builder()
  {
    _diag.emit( _level, _message );
  }
  
  diagnostic_builder diagnostic_engine::report( diagnostic_level level, const std::string& message )
  {
    ++number_of_diagnostics;
    return diagnostic_builder( *this, level, message );
  }
  
  void diagnostic_engine::emit( diagnostic_level level, const std::string& message ) const
  {
    using rang::style;
    using rang::fg;
  
    switch ( level )
    {
    case diagnostic_level::ignore:
      break;
    case diagnostic_level::note:
      std::cout << style::bold << fg::red << "[i] " << fg::reset
                << message << style::reset << std::endl;
      break;
    case diagnostic_level::remark:
      std::cerr << style::bold << fg::red << "[i] " << fg::reset
                << message << style::reset << std::endl;
      break;
    case diagnostic_level::warning:
      std::cerr << style::bold << fg::red << "[w] " << fg::reset
                << message << style::reset << std::endl;
      break;
    case diagnostic_level::error:
      std::cerr << style::bold << fg::red << "[e] " << fg::reset
                << message << style::reset << std::endl;
      break;
    case diagnostic_level::fatal:
      std::cerr << style::bold << fg::red << "[E] " << fg::reset
                << message << style::reset << std::endl;
      break;
    default:
      assert( false );
    }
  }
  
  class silent_diagnostic_engine : public diagnostic_engine
  {
  public:
    virtual void emit( diagnostic_level level, const std::string& message ) const override
    {
      (void)level;
      (void)message;
    }
  }; /* silent_diagnostic_engine */
  
  } // namespace lorina