// * This file is part of the COLOBOT source code
// * Copyright (C) 2001-2008, Daniel ROUX & EPSITEC SA, www.epsitec.ch
// *
// * 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 3 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, see  http://www.gnu.org/licenses/.

// taskadvance.cpp

#define STRICT
#define D3D_OVERLOADS

#include <windows.h>
#include <stdio.h>
#include <d3d.h>

#include "common/struct.h"
#include "graphics/d3d/d3dengine.h"
#include "math/old/math3d.h"
#include "common/event.h"
#include "common/misc.h"
#include "common/iman.h"
#include "graphics/common/terrain.h"
#include "object/object.h"
#include "physics/physics.h"
#include "object/brain.h"
#include "object/task/task.h"
#include "object/task/taskadvance.h"




// Object's constructor.

CTaskAdvance::CTaskAdvance(CInstanceManager* iMan, CObject* object)
						   : CTask(iMan, object)
{
}

// Object's destructor.

CTaskAdvance::~CTaskAdvance()
{
}


// Management of an event.

bool CTaskAdvance::EventProcess(const Event &event)
{
	if ( m_engine->RetPause() )  return true;
	if ( event.event != EVENT_FRAME )  return true;

	m_fixTime += event.rTime;

	// Momentarily stationary object (ant on the back)?
	if ( m_object->RetFixed() )
	{
		m_physics->SetMotorSpeedX(0.0f);  // stops the advance
		m_physics->SetMotorSpeedZ(0.0f);  // stops the rotation
		m_bError = true;
		return true;
	}

	m_timeLimit -= event.rTime;
	return true;
}


// Assigns the goal was achieved.

Error CTaskAdvance::Start(float length)
{
	m_direction = (length>=0.0f)?1.0f:-1.0f;
	m_totalLength = Abs(length);
	m_advanceLength = m_physics->RetLinLength(length);
	m_startPos = m_object->RetPosition(0);
	m_lastDist = 0.0f;
	m_fixTime = 0.0f;

	m_timeLimit = m_physics->RetLinTimeLength(m_totalLength, m_direction)*3.0f;
	if ( m_timeLimit < 2.0f )  m_timeLimit = 2.0f;

	m_physics->SetMotorSpeedX(m_direction*1.0f);  // forward/backward
	m_physics->SetMotorSpeedY(0.0f);
	m_physics->SetMotorSpeedZ(0.0f);

	m_bError = false;
	return ERR_OK;
}

// Indicates whether the action is finished.

Error CTaskAdvance::IsEnded()
{
	D3DVECTOR	pos;
	float		length;

	if ( m_engine->RetPause() )  return ERR_CONTINUE;

	if ( m_bError )
	{
		return ERR_STOP;
	}

	if ( m_timeLimit < 0.0f )
	{
		m_physics->SetMotorSpeedX(0.0f);
		return ERR_MOVE_IMPOSSIBLE;
	}

	pos = m_object->RetPosition(0);
	length = Length2d(pos, m_startPos);

	if ( length > m_lastDist )  // forward?
	{
		m_fixTime = 0.0f;
	}
	else	// still stands?
	{
		if ( m_fixTime > 1.0f )  // for more than a second?
		{
			m_physics->SetMotorSpeedX(0.0f);
			return ERR_MOVE_IMPOSSIBLE;
		}
	}
	m_lastDist = length;

	if ( length >= m_totalLength )
	{
		m_physics->SetMotorSpeedX(0.0f);
		m_physics->SetLinMotionX(MO_CURSPEED, 0.0f);

		if ( length != 0.0f )
		{
			pos = m_startPos+((pos-m_startPos)*m_totalLength/length);
			m_object->SetPosition(0, pos);
		}
		return ERR_STOP;
	}

	if ( length >= m_advanceLength )
	{
		m_physics->SetMotorSpeedX(m_direction*0.1f);
	}
	return ERR_CONTINUE;
}