/* gLife - An Artificial Life implementation using GNOME
 *
 * Copyright (C) 1999 Ali Abdin <aliabdin@aucegypt.edu>
 *
 * 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.
 */
#include <gnome.h>
#include <glade/glade.h>

#include "glife.h"
#include "data.h"
#include "simulation.h"
#include "move.h"

/* Prototypes */
gboolean move_animal (AnimalType *, gint, gint);
static void move_direction (AnimalType *, MoveDirection);
void random_movement (AnimalType *);
static void choose_direction_and_move  (AnimalType *, MoveChoices);

gboolean
move_animal (AnimalType *anim, gint x2, gint y2) {
	gint x1, y1;

        g_assert (anim != NULL);
	
	x1 = anim->posx;
	y1 = anim->posy;
        g_assert ((x2>0) && (x2<=MAXCOL+1));
        g_assert ((y2>0) && (y2<=MAXROW+1));	
	
	if (animal_exists (x2, y2))
		return FALSE; /* Spot Occupied */
	if (!animal_exists (x1, y1))
		return FALSE; /* Initial animal does not exist */
	
	/* Code to move Mr. Animal */
	terrain[anim->posx-1][anim->posy-1].occupied = FALSE;
	terrain[anim->posx-1][anim->posy-1].anim = NULL;
	terrain[x2-1][y2-1].occupied = TRUE;
	terrain[x2-1][y2-1].anim = anim;
	anim->posx = x2;
	anim->posy = y2;
	return TRUE;
}

static void
move_direction (AnimalType *animal, MoveDirection heading) {
	gboolean value;
	gint x, y;
	
       	x = animal->posx;
	y = animal->posy;
#if 0	
	g_assert ((x>0) && (x<=MAXCOL+1));
        g_assert ((y>0) && (y<=MAXROW+1));
#endif /* Assertions unecessary since the animal MUST be on the terrain */
	
	if (heading == UP) {
                value = move_animal (animal, x, y-1);
/*		g_print ("Up\n"); */
	}
	else if (heading == DOWN) {
                value = move_animal (animal, x, y+1);
/*		g_print ("Down\n"); */
	}
	else if (heading == RIGHT) {
		value = move_animal (animal, x+1, y);
/*		g_print ("Right\n"); */
	}
	else if (heading == LEFT) {
                value = move_animal (animal, x-1, y);
/*		g_print ("Left\n"); */
	}
	else
		g_assert_not_reached ();

	if (value == FALSE)
		/*	g_warning ("Movement of animal at %d,%d did not take place",x,y); */
		/* This will only occur if the place is occupied */
		;
	
}

static void
choose_direction_and_move (AnimalType *animal, MoveChoices move) {
	gint randval;
	/* We have 2^4 possible configurations for MoveChoices:
	 * TTTT TTTF TTFT TFTT TTFF TFTF TFFT TFFF 
	 * FFFF FFFT FFTF FTFF FFTT FTFT FTTF FTTT
	 */
/*	randval = 1 + (gint) (100.0*rand()/(RAND_MAX+1.0)); */
	randval = RAND (1,100);

	if (move.up && move.down && move.left && move.right)
		/* TTTT */
		if (randval > 75)
			move_direction (animal, UP);
		else if (randval > 50)
			move_direction (animal, DOWN);
		else if (randval > 25)
			move_direction (animal, LEFT);
		else
			move_direction (animal, RIGHT);
	else if (move.up && move.down && move.left)
		/* TTTF */
		if (randval > 67)
			move_direction (animal, UP);
		else if (randval > 33)
			move_direction (animal, DOWN);
		else 
			move_direction (animal, LEFT);
	else if (move.up && move.down && move.right)
		/* TTFT */
		if (randval > 67)
			move_direction (animal, UP);
		else if (randval > 33)
			move_direction (animal, DOWN);
		else 
			move_direction (animal, RIGHT);
	else if (move.up && move.down)
		/* TTFF */
		if (randval > 50)
			move_direction (animal, UP);
		else 
			move_direction (animal, DOWN);
	else if (move.up && move.left && move.right)
		/* TFTT */
		if (randval > 67)
			move_direction (animal, UP);
		else if (randval > 33)
			move_direction (animal, LEFT);
		else 
			move_direction (animal, RIGHT);
	else if (move.up && move.left)
		/* TFTF */
		if (randval > 50)
			move_direction (animal, UP);
		else 
			move_direction (animal, LEFT);
	else if (move.up && move.right)
		/* TFFT */
		if (randval > 50)
			move_direction (animal, UP);
		else
			move_direction (animal, RIGHT);
	else if (move.up)
		/* TFFF */
		move_direction (animal, UP);
	else if (move.down && move.left && move.right)
		/* FTTT */
		if (randval > 67)
			move_direction (animal, DOWN);
		else if (randval > 33)
			move_direction (animal, LEFT);
		else 
			move_direction (animal, RIGHT);
	else if (move.down && move.right)
		/* FTFT */
		if (randval > 50)
			move_direction (animal, DOWN);
		else 
			move_direction (animal, RIGHT);
	else if (move.down && move.left)
		/* FTTF */
		if (randval > 50)
			move_direction (animal, DOWN);
		else
			move_direction (animal, LEFT);
	else if (move.down)
		/* FTFF */
		move_direction (animal, DOWN);
	else if (move.left && move.right)
		/* FFTT */
		if (randval > 50)
			move_direction (animal, LEFT);
		else 
			move_direction (animal, RIGHT);
	else if (move.left)
		/* FFTF */
		move_direction (animal, LEFT);
	else if (move.right)
		/* FFFT */
		move_direction (animal, RIGHT);
	else
		/* No movement */;
}

void
random_movement(AnimalType *anim) {
	static guint updateblock = 0;

	/* Assume we can move anywhere */
	MoveChoices directions = { TRUE, TRUE, TRUE, TRUE };
#if 1
	if (updateblock >= 1) {
		updateblock = 0;
		while (gtk_events_pending())
			gtk_main_iteration();
	}
#endif
		
	if (anim->posx == 1) {
		directions.left = FALSE; /* somewhere on left column */
		if (anim->posy == 1) {
			/* Top Left Corner */
			directions.up = FALSE;
		}
		else if (anim->posy == MAXROW+1) {
			/* Bottom Left corner */
			directions.down = FALSE;
		}
	}
	else if (anim->posx == MAXCOL+1) {
		directions.right = FALSE; /* somewhere on right column */
		if (anim->posy == 1) {
			/* Top right corner */
			directions.up = FALSE;
		}
		else if (anim->posy == MAXCOL+1) {
			/* Bottom right corner */
			directions.down = FALSE;
		}
	}
	else if (anim->posy == 1) {
		/* Top row */
		directions.up = FALSE;
	}
	else if (anim->posy == MAXROW+1) {
		/* Bottom row */
		directions.down = FALSE;
	}
	/* If an animal exists then we can't move there !!! */
	if (directions.up)
		if (animal_exists (anim->posx, anim->posy-1))
			directions.up = FALSE;
	if (directions.down)
		if (animal_exists (anim->posx, anim->posy+1))
			directions.down = FALSE;
	if (directions.left)
		if (animal_exists (anim->posx-1, anim->posy))
			directions.left = FALSE;
	if (directions.right)
		if (animal_exists (anim->posx+1, anim->posy))
			directions.right = FALSE;
        choose_direction_and_move   (anim, directions);		
	updateblock++;					
}