/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Benjamin Grauer
   co-programmer: ...
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_SHELL

#include "shell.h"
#include "shell_command.h"
#include "shell_buffer.h"
#include "shell_input.h"

#include "multi_line_text.h"

#include "graphics_engine.h"
#include "material.h"
#include "event_handler.h"

namespace OrxShell
{

  SHELL_COMMAND(clear, Shell, clear)
  ->describe("Clears the shell from unwanted lines (empties all buffers)")
  ->setAlias("clear");
  SHELL_COMMAND(deactivate, Shell, deactivate)
  ->describe("Deactivates the Shell. (moves it into background)")
  ->setAlias("hide");
  SHELL_COMMAND(textsize, Shell, setTextSize)
  ->describe("Sets the size of the Text size, linespacing")
  ->defaultValues(15, 0);
  SHELL_COMMAND(textcolor, Shell, setTextColor)
  ->describe("Sets the Color of the Shells Text (red, green, blue, alpha)")
  ->defaultValues(SHELL_DEFAULT_TEXT_COLOR);
  SHELL_COMMAND(backgroundcolor, Shell, setBackgroundColor)
  ->describe("Sets the Color of the Shells Background (red, green, blue, alpha)")
  ->defaultValues(SHELL_DEFAULT_BACKGROUND_COLOR);
  SHELL_COMMAND(backgroundimage, Shell, setBackgroundImage)
  ->describe("sets the background image to load for the Shell")
  ->completionPlugin(0, OrxShell::CompletorFileSystem());
  SHELL_COMMAND(font, Shell, setFont)
  ->describe("Sets the font of the Shell")
  ->defaultValues(SHELL_DEFAULT_FONT)
  ->completionPlugin(0, OrxShell::CompletorFileSystem(".ttf", "fonts/"));


  /**
   * standard constructor
   */
  Shell::Shell ()
  {
    this->setClassID(CL_SHELL, "Shell");
    this->setName("Shell");

    // EVENT-Handler subscription of '`' to all States.
    EventHandler::getInstance()->subscribe(this, ES_ALL, SDLK_BACKQUOTE);
    EventHandler::getInstance()->subscribe(this, ES_ALL, SDLK_F12);
    EventHandler::getInstance()->subscribe(this, ES_SHELL, SDLK_PAGEUP);
    EventHandler::getInstance()->subscribe(this, ES_SHELL, SDLK_PAGEDOWN);

    // BUFFER
    this->bufferIterator = ShellBuffer::getInstance()->getBuffer().begin();

    // INPUT LINE
    this->setLayer(E2D_LAYER_ABOVE_ALL);
    this->shellInput.setLayer(E2D_LAYER_ABOVE_ALL);

    // Element2D and generals
    this->setAbsCoor2D(3, -400);
    this->textSize = 15;
    this->lineSpacing = 0;
    this->bActive = true;
    this->fontFile = SHELL_DEFAULT_FONT;

    this->setBufferDisplaySize(10);

    this->setTextColor(SHELL_DEFAULT_TEXT_COLOR);
    this->setBackgroundColor(SHELL_DEFAULT_BACKGROUND_COLOR);


    this->deactivate();
    // register the shell at the ShellBuffer
    ShellBuffer::getInstance()->registerShell(this);
  }

  /**
   * @brief standard deconstructor
   */
  Shell::~Shell ()
  {
    ShellBuffer::getInstance()->unregisterShell(this);

    // delete the displayable Buffers
    while (!this->bufferText.empty())
    {
      delete this->bufferText.front();
      this->bufferText.pop_front();
    }
  }

  /**
   * @brief activates the shell
   *
   * This also feeds the Last few lines from the main buffers into the displayBuffer
   */
  void Shell::activate()
  {
    if (this->bActive == true)
      PRINTF(3)("The shell is already active\n");
    this->bActive = true;

    EventHandler::getInstance()->pushState(ES_SHELL);
    EventHandler::getInstance()->withUNICODE(true);

    this->setRelCoorSoft2D(0, 0, 5);

    std::list<std::string>::const_iterator textLine = ShellBuffer::getInstance()->getBuffer().begin();
    for (std::list<MultiLineText*>::iterator text = this->bufferText.begin(); text != this->bufferText.end(); ++text)
    {
      (*text)->setVisibility(true);
      if (textLine !=  ShellBuffer::getInstance()->getBuffer().end())
      {
        (*text)->setText((*textLine));
        textLine++;
      }
      else
        (*text)->setText("");
    }
    repositionText();
  }

  /**
   * @brief deactiveates the Shell.
   */
  void Shell::deactivate()
  {
    if (this->bActive == false)
      PRINTF(3)("The shell is already inactive\n");
    this->bActive = false;

    EventHandler::getInstance()->withUNICODE(false);
    EventHandler::getInstance()->popState();

    this->setRelCoorSoft2D(0, -(int)this->shellHeight, 5);

    for (std::list<MultiLineText*>::iterator text = this->bufferText.begin(); text != this->bufferText.end(); ++text)
      (*text)->setVisibility(false);
    // Go to the End again.
    this->bufferIterator = ShellBuffer::getInstance()->getBuffer().begin();
  }

  /**
   * @brief sets the File to load the fonts from
   * @param fontFile the file to load the font from
   *
   * it is quite important, that the font pointed too really exists!
   * (be aware that within orxonox fontFile is relative to the Data-Dir)
   */
  void Shell::setFont(const std::string& fontFile)
  {
    this->fontFile = fontFile;

    this->applySettings();
  }

  /**
   * @brief sets the size of the text and spacing
   * @param textSize the size of the Text in Pixels
   * @param lineSpacing the size of the Spacing between two lines in pixels
   *
   * this also rebuilds the entire Text, inputLine and displayBuffer,
   * to be accurate again.
   */
  void Shell::setTextSize(unsigned int textSize, unsigned int lineSpacing)
  {
    this->textSize = textSize;
    this->lineSpacing = lineSpacing;

    this->applySettings();
  }

  /**
   * @brief sets the color of the Font.
   * @param r: red
   * @param g: green
   * @param b: blue
   * @param a: alpha-value.
   */
  void Shell::setTextColor(float r, float g, float b, float a)
  {
    this->textColor[0] = r;
    this->textColor[1] = g;
    this->textColor[2] = b;
    this->textColor[3] = a;

    this->applySettings();
  }

  /**
   * @brief sets the color of the Backgrond.
   * @param r: red
   * @param g: green
   * @param b: blue
   * @param a: alpha-value.
   */
  void Shell::setBackgroundColor(float r, float g, float b, float a)
  {
    this->backgroundMaterial.setDiffuse(r, g, b);
    this->backgroundMaterial.setTransparency(a);
  }

  /**
   * @brief sets a nice background image to the Shell's background
   * @param fileName the filename of the Image to load
   */
  void Shell::setBackgroundImage(const std::string& fileName)
  {
    this->backgroundMaterial.setDiffuseMap(fileName);
  }

  /**
   * @brief repositiones all the Texts to their position.
   */
  void Shell::repositionText()
  {
    int linePos = -1;
    std::list<MultiLineText*>::iterator textIt;
    for (textIt = this->bufferText.begin() ; textIt != this->bufferText.end(); ++textIt )
    {
      linePos += (*textIt)->getLineCount();
      (*textIt)->setRelCoorSoft2D(this->calculateLinePosition(linePos), 8);
    }
  }


  /**
   * @brief applies the Shells Settings to a single Text of the Shell.
   * @param text the Text to apply the settings to.
   */
  void Shell::applyTextSettings(Text* text)
  {
    text->setSize(this->textSize);
    text->setFont(this->fontFile, this->textSize);
    text->setColor(this->textColor[0], this->textColor[1], this->textColor[2]);
    text->setBlending(this->textColor[3]);
    text->setLayer(this->getLayer());
    if (text->getParent2D() != this)
      text->setParent2D(this);
  }

  /**
   * @brief resets the Values of all visible shell's commandos to the Shell's stored values
   *
   * this functions synchronizes the stored Data with the visible one.
   */
  void Shell::applySettings()
  {
    this->applyTextSettings(&this->shellInput);
    this->shellInput.setRelCoor2D(15, (this->textSize + this->lineSpacing)*(this->bufferDisplaySize));

    /* Here we create a Copy of the Buffer, so that we do not f**k up the List when some
     * output is routed from Some other Thread or by Changing any Values.
     */
    std::list<MultiLineText*> bufferTextCopy = this->bufferText;
    for (std::list<MultiLineText*>::iterator textIt = bufferTextCopy.begin(); textIt != bufferTextCopy.end(); ++textIt)
    {
      this->applyTextSettings(*textIt);
      (*textIt)->setLineSpacing(this->lineSpacing);
      (*textIt)->setLineWidth(this->getSizeX2D() * GraphicsEngine::getInstance()->getResolutionX());
    }
    this->repositionText();

    this->shellHeight = (this->textSize + this->lineSpacing) * (bufferDisplaySize+1);
  }

  /**
   * @brief sets The count of Lines to display in the buffer.
   * @param bufferDisplaySize the count of lines to display in the Shell-Buffer.
   */
  void Shell::setBufferDisplaySize(unsigned int bufferDisplaySize)
  {
    unsigned int oldSize = this->bufferText.size();
    if (oldSize > bufferDisplaySize)
    {
      for (unsigned int i = bufferDisplaySize; i <= oldSize; i++)
      {
        delete this->bufferText.back();
        this->bufferText.pop_back();
      }
    }
    else if (oldSize < bufferDisplaySize)
    {
      for (unsigned int i = oldSize; i <= bufferDisplaySize; i++)
      {
        this->bufferText.push_back(new MultiLineText);
      }
    }
    this->bufferDisplaySize = bufferDisplaySize;
    this->applySettings();
  }

  /**
   * @brief deletes all the Buffers
   */
  void Shell::flush()
  {
    for (std::list<MultiLineText*>::iterator textIt = this->bufferText.begin(); textIt != this->bufferText.end(); ++textIt)
    {
      (*textIt)->setText("");  // remove all chars from the BufferTexts.
    }
    ShellBuffer::getInstance()->flush();
    // BUFFER FLUSHING
  }

  /**
   * @brief prints out some text to the input-buffers
   * @param text the text to output.
   */
  void Shell::printToDisplayBuffer(const std::string& text)
  {
    // Remove Last Entry and prepend it to the front.
    this->bufferText.push_front(this->bufferText.back());
    this->bufferText.pop_back();

    // Set the new Text.
    this->bufferText.front()->setText(text);

    // The LineCount will be started here.

    // The First Line gets a special Animation
    this->bufferText.front()->setRelCoor2D(this->calculateLinePosition(0)- Vector2D(-1000,0));

    // Move all lines one Entry up.
    this->repositionText();
  }


  /**
   * @brief moves the Display buffer (up + or down - )
   * @param lineCount the count by which to shift the InputBuffer.
   *
   * @todo make this work
   */
  void Shell::moveDisplayBuffer(int lineCount)
  {
    // moving the iterator to the right position (counting the steps)
    int moves = 0;
    while (moves != lineCount)
    {
      if (moves < lineCount)
      {
        if(this->bufferIterator == --ShellBuffer::getInstance()->getBuffer().end())
          break;
        ++moves;
        ++this->bufferIterator;
      }
      else
      {
        if (this->bufferIterator == ShellBuffer::getInstance()->getBuffer().begin())
          break;
        --moves;
        --this->bufferIterator;
      }
    }


    // redisplay the buffers
    std::list<MultiLineText*>::iterator textIt;

    // Give a Graphical Representation that no move is possible.
    if (moves == 0)
    {
      int linePos = -1;
      for (textIt = this->bufferText.begin(); textIt != this->bufferText.end(); ++textIt)
      {
        linePos += (*textIt)->getLineCount();
        (*textIt)->setRelCoor2D(this->calculateLinePosition(linePos)+ Vector2D(20,0));
        (*textIt)->setRelCoorSoft2D(this->calculateLinePosition(linePos), 10);
      }
      return;
    }

    // Move all the Lines.
    int linePos = moves;
    std::list<std::string>::const_iterator it = this->bufferIterator;
    for (textIt = this->bufferText.begin(); textIt != this->bufferText.end(); ++textIt, ++it)
    {
      if (it == ShellBuffer::getInstance()->getBuffer().end())
      {
        PRINTF(1)("LAST LINE REACHED\n");
        break;
      }


      (*textIt)->setRelCoor2D(calculateLinePosition( (linePos++ > 0)? linePos : 0));
      (*textIt)->setText((*it));
    }
    while (textIt != this->bufferText.end())
    {
      (*textIt)->setText("");
      textIt++;
    }

    this->repositionText();
  }

  /**
   * @brief clears the Shell (empties all buffers)
   */
  void Shell::clear()
  {
    this->flush();
    ShellBuffer::addBufferLineStatic("orxonox - shell\n ==================== \n", NULL);
  }

  /**
   * @brief listens for some event
   * @param event the Event happened
   */
  void Shell::process(const Event &event)
  {
    if (event.bPressed)
    {
      if (event.type == SDLK_BACKQUOTE || event.type == SDLK_F12)
      {
        if (this->bActive == false)
          this->activate();
        else
          this->deactivate();
      }
      else if (event.type == SDLK_PAGEUP)
      {
        this->moveDisplayBuffer(+this->bufferDisplaySize-1);
      }
      else if (event.type == SDLK_PAGEDOWN)
      {
        this->moveDisplayBuffer(-this->bufferDisplaySize+1);
      }
    }
  }

  /**
   * displays the Shell
   */
  void Shell::draw() const
  {
    // transform for alignment.
    // setting the Blending effects

    this->backgroundMaterial.select();

    glBegin(GL_TRIANGLE_STRIP);

    glTexCoord2f(0, 0);
    glVertex2f(this->getAbsCoor2D().x,   this->getAbsCoor2D().y  );

    glTexCoord2f(1, 0);
    glVertex2f(GraphicsEngine::getInstance()->getResolutionX() - this->getAbsCoor2D().x, this->getAbsCoor2D().y  );

    glTexCoord2f(0, 1);
    glVertex2f(this->getAbsCoor2D().x, this->getAbsCoor2D().y + this->shellHeight);

    glTexCoord2f(1, 1);
    glVertex2f(GraphicsEngine::getInstance()->getResolutionX() - this->getAbsCoor2D().x, this->getAbsCoor2D().y + this->shellHeight);

    glEnd();
  }

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

  /**
   * @brief calculates the position of a Buffer-Display Line
   * @param lineNumber the lineNumber from the bottom to calculate the position from
   * @returns the Position of the Line.
   */
  Vector2D Shell::calculateLinePosition(unsigned int lineNumber)
  {
    return Vector2D(5, (int)(this->textSize + this->lineSpacing)*(int)((int)this->bufferDisplaySize - (int)lineNumber - (int)2) + (int)this->textSize);
  }



  /**
   * @brief displays some nice output from the Shell
   */
  void Shell::debug() const
  {
    PRINT(3)("Debugging output to console (not this shell)\n");

    //   if (this->pressedKey != SDLK_FIRST)
    //     printf("%s::%f %f\n", SDLKToKeyname(this->pressedKey), this->delayed, this->repeatDelay);


    ShellBuffer::getInstance()->debug();
  }

  /**
   * @brief a Handy Function, to Test the behaviour of the Shell.
   */
  void Shell::testShell() const
  {
    for (unsigned int i = 0; i < 100; i++)
      PRINT(0)("%d\n", i);
  }
  SHELL_COMMAND(test, Shell, testShell);

}