/*
 *  VHDL abstract syntax elements.
 *
 *  Copyright (C) 2008  Nick Gasson (nick@nickg.me.uk)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "vhdl_element.hh"

#include <algorithm>


//////// HELPER FUNCTIONS ////////

static const int VHDL_INDENT = 2;  // Spaces to indent

static int indent(int level)
{
   return level + VHDL_INDENT;
}

/*
 * Emit a newline and indent to the correct level.
 */
static void newline(std::ofstream &of, int level)
{
   of << std::endl;
   while (level--)
      of << ' ';
}

static void blank_line(std::ofstream &of, int level)
{
   of << std::endl;
   newline(of, level);
}

template <class T>
void emit_children(std::ofstream &of,
                   const std::list<T*> &children,
                   int level) 
{      
   // Don't indent if there are no children
   if (children.size() == 0)
      newline(of, level);
   else {
      typename std::list<T*>::const_iterator it;
      for (it = children.begin(); it != children.end(); ++it) {
         newline(of, indent(level));
         (*it)->emit(of, indent(level));
      }
      newline(of, level);
   }
}


//////// ALL ELEMENTS ////////

void vhdl_element::set_comment(std::string comment)
{
   comment_ = comment;
}

void vhdl_element::emit_comment(std::ofstream &of, int level) const
{
   if (comment_.size() > 0) {
      of << "-- " << comment_;
      newline(of, level);
   }
}


//////// ENTITY ////////

vhdl_entity::vhdl_entity(const char *name)
   : name_(name)
{

}

void vhdl_entity::emit(std::ofstream &of, int level) const
{
   emit_comment(of, level);
   of << "entity " << name_ << " is";
   // ...ports...
   // newline(indent(level));
   newline(of, level);
   of << "end entity; ";
   blank_line(of, level);  // Extra blank line after entities
}


//////// ARCHITECTURE ////////

vhdl_arch::vhdl_arch(const char *entity, const char *name)
   : name_(name), entity_(entity)
{
   
}

void vhdl_arch::add_stmt(vhdl_conc_stmt* stmt)
{
   stmts_.push_back(stmt);
}

void vhdl_arch::emit(std::ofstream &of, int level) const
{
   emit_comment(of, level);
   of << "architecture " << name_ << " of " << entity_;
   of << " is";
   // ...declarations...
   // newline(indent(level));
   newline(of, level);
   of << "begin";
   emit_children<vhdl_conc_stmt>(of, stmts_, level);
   of << "end architecture;";
   blank_line(of, level);  // Extra blank line after architectures;
}


//////// PROCESS ////////

vhdl_process::vhdl_process(const char *name)
   : name_(name)
{

}

void vhdl_process::add_stmt(vhdl_seq_stmt* stmt)
{
   stmts_.push_back(stmt);
}

void vhdl_process::emit(std::ofstream &of, int level) const
{
   emit_comment(of, level);
   if (name_)
      of << name_ << ": ";
   of << "process is";  // TODO: sensitivity
   newline(of, level);
   // ...declarations...
   of << "begin";
   newline(of, level);
   // ...statements...
   of << "wait;";   // Just to stop the simulation hanging
   newline(of, level);
   of << "end process;";
   newline(of, level);
}