#include <locale.h>
#include <string.h>
#include <wchar.h>
#include <stdio.h>
#include <stdlib.h>

#define E 0 /* empty  */
#define K 1 /* king */
#define Q 2 /* queen  */
#define R 3 /* rook */
#define B 4 /* bishop */
#define N 5 /* knight */
#define P 6 /* pawn */

#define WHITE 1
#define BLACK -1

void setcolor(int mode, int r, int g, int b);
void print_board(int* board);
void init_board(int* board);

/*
 * main
 */
int main(){
	setlocale(LC_ALL, "C.UTF-8");

	int *board;
	init_board(board);
	print_board(board);

	return 0;
}


/*
 * Sets the foreground or background color.
 * Modes:
 *  - 0: change background
 *  - 1: change foreground
 *  - 2: reset colors
 */
void setcolor(int mode, int r, int g, int b){
	if( mode == 2 )
		printf("\033[0m");
	else
		printf("\033[%i;2;%i;%i;%im", mode?38:48, r, g, b);
};


/*
 * Prints the board
 */
void print_board(int* board){
	wchar_t piece;

	/*
		The loop checks if the tile is empty and prints ' ' if so.
		Otherwise the foreground color is set to match the player
		and the unicode symbol for the piece is printed.

		The unicode value for a fullcolor chess king is 0x2654
		the following unicode 5 unicode characters are the 
		other white chess pieces. (matches macro definitions)
		(https://en.wikipedia.org/wiki/Chess_symbols_in_Unicode) 
	
		The unicode symbol is calculated from adding 0x2653 and the
		piece value.
	*/

	for(int i=0; i<8; i++){
		printf("\n %i ", 8-i); // number coordinates

		for(int j=0; j<8; j++){	
			int p = board[i*8+j];
			
			// Make tiles black and white 
			if((i+j) % 2)
				setcolor(0, 100, 100, 150);
			else
				setcolor(0, 150, 150, 200);


			// Print empty space and do nothing if tile is empty
			if(p == E){
				printf("  ");
				continue;
			}

			// Set piece color
			if(p > 0){
				setcolor(1, 0xff, 0xff, 0xff); //white
			}else{
				setcolor(1, 0, 0, 0); //black
				p *= -1;
			}
			
			printf("%lc ", 0x2659 + p);
		}

		setcolor(2, 0, 0, 0); // reset text attributes
	}
	
	// Print horizontal letter coordinates
	printf("\n  ");
	for(int i=0; i<8; i++) printf(" %c", 'a'+i);
}


/*
 * Resets/inits the board
 */
void init_board(int *board){
	
	// black pieces are prefixed by a minus (-)
	const int start[] = {
		-R,-N,-B,-Q,-K,-B,-N,-R, 
		-P,-P,-P,-P,-P,-P,-P,-P, 
		 E, E, E, E, E, E, E, E, 
		 E, E, E, E, E, E, E, E, 
		 E, E, E, E, E, E, E, E, 
		 E, E, E, E, E, E, E, E, 
		 P, P, P, P, P, P, P, P, 
		 R, N, B, Q, K, B, N, R
	};

	memcpy(board, start, sizeof(start));
}