/*
   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: ...
   co-programmer: ...
*/

//#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_

#include "quick_animation.h"

#include "compiler.h"
#include "debug.h"
#ifndef NULL
#define NULL 0
#endif


using namespace std;

/**
 *  standard constructor
*/
QuickAnimation::QuickAnimation ()
{
   this->setClassID(CL_QUICK_ANIMATION, "QuickAnimation");

   // initialize the First KeyFrame (will be deleted if a new one gets created)
   this->count = 0;
   this->first = this->current = new QuickKeyFrame;
   this->first->next = this->first->prev = this->first;
   this->first->position = 0.0;
   this->first->value = 0.0;
}

/**
 *  deletes all the deconstructor stuff
*/
QuickAnimation::~QuickAnimation ()
{
  this->current = this->first;
  QuickKeyFrame* delKF = this->first;

  do
  {
    delKF = this->current;
    this->current = this->current->next;
    delete delKF;
  }  while (this->current != this->first);

}

/**
 *  adds a new entry to the list of keyframes
 * @param position the position to add the key to
 * @param value the Value to set for the position
 * @returns false if the key existed already for a given position
*/
void QuickAnimation::addEntry(float position, float value)
{
  // create the new KeyFrame
  QuickKeyFrame* newKey = new QuickKeyFrame;
  newKey->position = position;
  newKey->value = value;

  // if we add a KeyFrame for the first Time:
  if (unlikely (this->count == 0))
  {
    delete this->first;

    newKey->next  = newKey;
    newKey->prev  = newKey;
    this->first   = newKey;
    this->current = newKey;
  }
  // if the KeyFrame is in front of the FIRST keyFrame
  else if (this->first->position > position)
  {
    newKey->next = this->first;
    newKey->prev = this->first->prev;
    newKey->prev->next = newKey;
    newKey->next->prev = newKey;

    this->first = newKey; // the new Key becomes the FIRST.
  }
  // if the KeyFrame is at the End of the Animation
  else if (this->first->prev->position < position)
  {
    newKey->next = this->first;
    newKey->prev = this->first->prev;
    newKey->prev->next = newKey;
    newKey->next->prev = newKey;
  }
  // if the Key is between two frames.
  else
  {
    this->current = this->first;
    do
    {
      if (this->current->position < position && this->current->next->position > position)
        break;
      // if it is the same as an already existing keyframe
      else if (this->current->position == position)
      {
        this->current->value = value;
        delete newKey;
        return;
      }
      this->current = this->current->next;
    } while (this->current != this->first);

    newKey->next = this->current->next;
    newKey->prev = this->current;
    newKey->next->prev = newKey;
    newKey->prev->next = newKey;
  }
  this->current = this->first;
  ++this->count;
}

/**
 *  changes an entry in the region of position
 * @param position the Position of an existing keyframe
 * @param region a deviation of the existing keyframe (like a delta in witch to search for
 * @param value the new Value

   if the Entry at the in the region of the specified position is found, it will be changed.
    Otherwise a new KeyFrame will be created with value at position.
   @todo rimplement
*/
void QuickAnimation::changeEntry(float position, float value, float region)
{

  if ((this->first->position > position + region) || this->first->prev->position < position - region || this->count == 0)
    this->addEntry(position, value);
  else
  {
    this->current = this->first;
    do
    {
      if (this->current->position > position + region)
      {
        this->addEntry(position, value);
        return;
      }
      if (this->current->position < position+region && this->current->position > position-region)
      {
        this->current->value = value;
        return;
      }
      this->current = this->current->next;
    }  while (this->current != this->first);
  }
}


/**
 * removes a KeyFrame from the List.
 * @param position
 * @return
 */
void QuickAnimation::removeEntry(float position)
{
  this->current = this->first;

  if (this->count <= 0)
  {
    this->current->value = 0.0;
    this->current->position = 0.0;
    count = 0;
    return;
  }
  else
  {
    do
    {
      if (this->current->position == position)
      {
        if (this->current == this->first)
          this->first = this->first->next;
        this->current->next->prev = this->current->prev;
        this->current->prev->next = this->current->next;
        delete this->current;
        break;
      }
      this->current = this->current->next;
    } while (this->current != this->first);

    count --;
    this->current = this->first;
  }
}


/**
 *  returns the value of the animation at a certain position
 * @param position the position to get the value from :)
*/
float QuickAnimation::getValue(float position)
{
  while (true)
  {
    // if we have a match
    if (likely(this->current->position <= position && this->current->next->position >= position))
      return this->current->value + (this->current->next->value - this->current->value)
          * ((position-this->current->position) / (this->current->next->position -this->current->position));

    else if (unlikely(this->first->prev->position < position))
      return this->first->prev->value;
    else if (unlikely(this->first->position > position))
      return this->first->value;
    else if(likely(this->current->next->position < position))
      this->current = this->current->next;
    else if (likely(this->current->position > position))
      this->current = this->current->prev;
  }
}

/**
 *  outputs some nice information about this class
*/
void QuickAnimation::debug()
{
  this->current = this->first;

  PRINT(0)("QuickAnim(entries:%d)::(position, value)", this->count);
  do
    {
      PRINT(0)("->(%f, %f)", this->current->position, this->current->value);
      this->current = this->current->next;
    } while(this->current != this->first);

  PRINT(0)("\n");
  this->current = this->first;
}