/**
 * nInvaders - a space invaders clone for ncurses
 * Copyright (C) 2002-2003 Dettus
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * homepage: http://ninvaders.sourceforge.net
 * mailto: ninvaders-devel@lists.sourceforge.net
 *
 */
 

#include "ufo.h"
#include "aliens.h"
#include "nInvaders.h"

static int fShowUfo = 0;

/**
 * initialize ufo attributes
 */
void ufoReset()
{
	ufoClear(ufo.posX, ufo.posY);	// clear old position of player

	fShowUfo = 0;                   // do not show ufo
	ufo.posY = UFOPOSY;	        // set vertical Position
	ufo.posX = SCREENWIDTH - UFOWIDTH;// set horizontal Position
}

/**
 * move ufo horizontally to position posX
 */
static void ufoMove(int posX)
{
	ufoClear(ufo.posX, ufo.posY);   // clear sprite
	ufo.posX = posX;
	ufoRefresh();
	ufoDisplay(ufo.posX, ufo.posY);
}


/**
 * move ufo and check if it reached the left screen border
 */
void ufoMoveLeft()
{
	// check if space between ufo and screen border is big enough 
	if (ufo.posX > 1) {
		// desired movement is possible
		ufoMove(ufo.posX - 1);
	} else {
		ufoReset();
	}
}

/**
 * check if the first screen line is free for the ufo and
 * display it randomly
 */
int ufoShowUfo()
{
	if (aliens.posY > 0 && fShowUfo == 0) { // aliens one line down
		if ((random() % 200) == 0) {
			fShowUfo = 1;
		}
	}

	return fShowUfo;
}

/**
 * check if ufo was hit by player and delete it from screen
 */
int ufoHitCheck(int shotX, int shotY)
{
	int fUfoWasHit = 0;
	
	// if shot reached vertikal position of ufo
	if (shotY == UFOPOSY) {
		// if shot hits ufo
		if (shotX >= ufo.posX && shotX <= ufo.posX + UFOWIDTH -1) {
			ufoReset();
			fUfoWasHit = 1;
		}
	}
	
	return fUfoWasHit;
}