/* This is the .aud file for the "ski" demo.
 *
 * Source code:   ambiences/ski/ski.c
 * .aud file:     ambiences/ski/ski.aud
 * Documentation: ambiences/HowTo.html
 */

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <sys/types.h>
#include <bstring.h>
#include <sys/time.h>
#include "vssClient.h"

void PrintBlanks();
int  RandAB();
int  ReadKeyboard();

void main()
{
	int left = 25;	/* position of left edge, skier, right edge */
	int skier = 40;
	int right = 55;
	int c;

	if (!BeginSoundServer()) {
		printf("Connection to sound server failed.  Is vss running?\n");
        	exit(2);
    	}
    
    	AUDinit("ski.aud");	/* open the .aud file */
	
    	printf("a -- left\ns -- right\nq -- quit\n\n");

	system("stty -echo raw");	/* set up the terminal */
	sginap(400);

	for (;;)
		{
		sginap(15);		/* Game speed */

		/* Draw the game. */

		PrintBlanks(left);
		putchar(']');
		PrintBlanks(skier-left-1);
		putchar('S');
		PrintBlanks(right-skier-1);
		putchar('[');
		putchar('\r');
		putchar('\n');

		/* Adjust the ski slope. */

		if (RandAB(1, 8) == 1)
			{
			/* narrow the ski slope by one */
			if (RandAB(1, 2) == 1)
				left++;
			else
				right--;

			/* if the slope got narrow enough, player wins! */
			if (right - left <= 9)
				{
				/* send messages for "Win" */
        			AUDupdateSimple("Win", 0, NULL);
				printf("\n\n\nYou win!\n\n");
				break;
				}
			}
		else
			{
			/* move the ski slope left or right */
			int jog = RandAB(-1, 1);
			left  += jog;
			right += jog;
			}

		/* Get position of skier. */
		c = ReadKeyboard();
		if (c == 'a') {
			skier--;
			/* send messages for "Turn Left" */
        		AUDupdateSimple("TurnL", 0, NULL);
		}
		else if (c == 's') {
			skier++;
			/* send messages for "Turn Right" */
        		AUDupdateSimple("TurnR", 0, NULL);
		}
		else if (c == 'q')
			break;

		/* keep everything less than 80 columns */
		if (left  < 0) left  = 0; else if (left  > 79) left  = 79;
		if (right < 0) right = 0; else if (right > 79) right = 79;
		if (skier < 0) skier = 0; else if (skier > 79) skier = 79;

		/* did skier run into the edge of the slope? */
		if (skier <= left || skier >= right)
			{
			/* send messages for "Crash" */
        		AUDupdateSimple("Crash", 0, NULL);
			printf("You lose!\n");
			break;
			}
		}
	sginap(150);

	system("stty echo -raw");

        AUDupdateSimple("Exit", 0, NULL);  	/* send messages for "Exit" */
	sginap(400);				/* wait for sound to finish */

	/* Essential cleanup. */
	EndSoundServer();
}


/* print n blanks */
void PrintBlanks(int n)
{
	const char blanks[81] = "                                                                                ";

	if (n > 0 && n <= 80)
		printf(blanks + 80 - n);
}


/* return a number in the range a to b inclusive */
int RandAB(int a, int b)
{
	return (rand() % (b-a+1)) + a;
}


/* stuff for polling the keyboard */
fd_set fds;
struct timeval timeout = { 0, 0 };
int ReadKeyboard(void)
{
	FD_CLR(0, &fds);
	FD_SET(0, &fds);
	if (select(1, &fds, NULL, NULL, &timeout) == 1)
		return getchar();
	return 0;
}