//	TticTacToe.cpp - Use: http://localhost/CGI/tictactoe.exe

#include <iostream.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

extern "C" int STRindex( char p[], char s[]) {
	int pl = strlen(p), sl = strlen(s);
	int pi = 0, si = 0;

	do {
		if(p[pi] == s[si]) {
			pi++;
			si++;
		}
		else {
			pi = 0;
			si++;
		}
	} while (pi < pl && si < sl);

	if (pi == pl)
		return si-pl;
	else
		return -1;
}

extern "C" void STRcpy(char s1[], char s2[]) {
	int i1=0, i2=0;

	while( s1[i1] != '\0')
		s2[i2++] = s1[i1++];
	s2[i2] = '\0';
}

extern "C" int endgame(char board[]) {
	for (int i=0; i<=8; i++) 
		if (board[i]==(char)(i+'0'))
			return 0;
	return 1;
}

char * render(char message[], char board[]) {
	char *result=new char[128];
	char move[]=" | | \n<br>";
	char line[]="_|_|_\n<br>";
	STRcpy(message, result);
	for (int i = 0; i<=5; i=i+3) {
		move[0]=board[i];
		move[2]=board[i+1];
		move[4]=board[i+2];
		STRcpy(move,result+strlen(result));
		STRcpy(line,result+strlen(result));
	}
	move[0]=board[6];
	move[2]=board[7];
	move[4]=board[8];
	STRcpy(move,result+strlen(result));
	return result;
}

char * place(char symbol, char move, char board[]) {
	int i = (int)(move - '0');
	if (i >= 0 && i <= 8) 
		if (board[i] == move) {
			board[i] = symbol;
			return  render("\n<br>", board);
		}
	return render("Bad move!\n<br>", board);
}

char * process(char clientinput[]) {
	char board[10];
	char *result = new char[500];
	char *game;
	char move;
	int  index;
	if(clientinput == NULL) clientinput = "";
				// Build browser controls
	STRcpy("<b>TicTacToe\n</b><br>Enter Move X.<pre>", result);
	STRcpy("<form action=\"tictactoe.exe\" method=\"POST\">", result+strlen(result));
	STRcpy("<input type=\"text\" name=\"move\" size=2>\n",result+strlen(result));
														// If no board variable, new game
	if((index=STRindex("board=", clientinput)) == -1) {
		STRcpy("<input type=\"hidden\" name=\"board\" value=\"012345678\"></form>\n",
		  result+strlen(result));
		STRcpy(render("", "012345678"), result+strlen(result));
	}
	else {												// Old game, get current board & move
		for(int i=0; i<=8; i++)
			board[i] = clientinput[index+6+i];
		board[9]='\0';

		index = STRindex("move=", clientinput);
		move = clientinput[index+5];

		if(!endgame(board))								// Place x on game board
			game = place('x', move, board);				// game contains HTML of board
		else {
			STRcpy("012345678", board);					// Game over, initialize board empty
			game = "Game Over";
			STRcpy("<b>New Game. o moves.</b><br>\n", result+strlen(result));
		}

		if (!endgame(board) && STRindex("Bad", game) == -1) // If X move OK make O move
			do {											// Random move
				game = place('o', (char)(rand()%9)+'0', board);
			} while (STRindex("Bad", game) >= 0);

		STRcpy(game,result+strlen(result));					// Copy current game board

		STRcpy("</pre>", result+strlen(result));			// Copy HTML for board variable 
		STRcpy("<input type=\"hidden\" name=\"board\" value=\"", result+strlen(result));
		STRcpy(board,result+strlen(result));
		STRcpy("\"></form>\n",result+strlen(result));
	}
	return result;
}

//												// TicTacToe server on Port 80
void main(void)
{
	char input[4096]; 
	int length; 

	cout << "Content-type: text/html\n\n"; 
	sscanf( getenv("CONTENT_LENGTH"), "%d", &length); 
	for (int i=0; i<length; i++) cin >> input[i]; 
	input[length]='\0'; 
cout << input << "<br>";
	cout << process(input);
}