/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * Additional copyright for this file:
 * Copyright (C) 1995-1997 Presto Studios, Inc.
 *
 * 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/>.
 *
 */

#include "pegasus/movie.h"
#include "pegasus/pegasus.h"
#include "pegasus/neighborhood/mars/constants.h"
#include "pegasus/neighborhood/mars/hermite.h"
#include "pegasus/neighborhood/mars/planetmover.h"
#include "pegasus/neighborhood/mars/shuttleenergymeter.h"

namespace Pegasus {

static const TimeScale kRovingScale = kTractorBeamScale;
static const TimeValue kRovingTime = kTenSeconds * kRovingScale;
static const TimeValue kRovingSlop = kTwoSeconds * kRovingScale;

static const CoordType kMaxVelocity = 20;

PlanetMover::PlanetMover() {
	setScale(kRovingScale);
	_dropping = false;
	_planetMovie = nullptr;
}

void PlanetMover::startMoving(Movie *planetMovie) {
	_planetMovie = planetMovie;
	_p4 = kPlanetStartTop;
	_r4 = g_vm->getRandomNumber(kMaxVelocity - 1);
	if (_r4 + _p4 < kPlanetStopTop)
		_r4 = kPlanetStopTop - _p4;
	newDestination();
}

void PlanetMover::stopMoving() {
	stop();
}

void PlanetMover::dropPlanetOutOfSight() {
	stop();
	CoordType currentLoc = hermite(_p1, _p4, _r1, _r4, _lastTime, _duration);
	CoordType currentV = dHermite(_p1, _p4, _r1, _r4, _lastTime, _duration);
	_p1 = currentLoc;
	_r1 = currentV;
	_p4 = kPlanetStartTop;
	_r4 = 0;
	_duration = kTractorBeamTime - kTractorBeamScale;
	_dropping = true;
	setSegment(0, _duration);
	setTime(0);
	start();
}

void PlanetMover::newDestination() {
	_p1 = _p4;
	_r1 = _r4;

	_p4 = kPlanetStopTop + g_vm->getRandomNumber(kPlanetStartTop - kPlanetStopTop - 1);
	_r4 = g_vm->getRandomNumber(kMaxVelocity - 1);

	if (_r4 + _p4 < kPlanetStopTop)
		_r4 = kPlanetStopTop - _p4;

	stop();
	_duration = kRovingTime + g_vm->getRandomNumber(kRovingSlop - 1);
	setSegment(0, _duration);
	setTime(0);
	start();
}

void PlanetMover::timeChanged(const TimeValue) {
	if (_planetMovie) {
		_planetMovie->moveElementTo(kPlanetStartLeft, hermite(_p1, _p4, _r1, _r4, _lastTime, _duration));
		if (_lastTime == _duration) {
			if (_dropping)
				stop();
			else
				newDestination();
		}
	}
}

} // End of namespace Pegasus