#include <cairo.h>
#include <cairo-xlib.h>
#include "chess.h"

/* keycodes */
#define XK_MISCELLANY
#include <X11/keysymdef.h>

struct {
	Display *dpy;
	int scr;

	Window win;
	GC gc;
	int width, height;
	KeyCode quit_code;
} boardWindow;

/* large portions of this sporked from a free example I found - therefore its
 * copyright status is indeterminate */

void input(char *buf, size_t len)
{
	/* this is just ANSI input since cairo is still beyond me for the time 
	 * being */
	if(feof(inputstream))
	{
		if(inputstream != stdin && !feof(stdin))
			inputstream = stdin;
		else
		{
			strncpy(out, "EOF reached on input", sizeof(out));
			output();
			exit(ERROR);
		}
	}
	while(1)
	{
		fgets(buf, len, inputstream);
		if(strncmp(buf, "//", 2))
			break;
	}
	if(strchr(buf, '\n'))
		*strchr(buf, '\n') = '\0';
}

static void board_create()
{
	boardWindow.dpy = XOpenDisplay(0);
	if(!boardWindow.dpy)
	{
		fprintf(stderr, "Failed to open display\n");
		exit(ERROR);
	}
}

static void board_redraw()
{
	int i, x, y, xpos, ypos;
	cairo_surface_t *surface;
	cairo_t *cr;
	Visual *visual;
	int square_size;

	visual = DefaultVisual(boardWindow.dpy, DefaultScreen(boardWindow.dpy));
	surface = cairo_xlib_surface_create(boardWindow.dpy, boardWindow.win, 
		visual, boardWindow.width, boardWindow.height);
	cr = cairo_create(surface);

	cairo_set_source_rgb(cr, 255, 0, 0);
	cairo_rectangle(cr, 0, 0, boardWindow.width, boardWindow.height);
	cairo_fill(cr);

	square_size = boardWindow.width / 9;
	for(i = 0; i < 64; i++)
	{
		x = i % 8;
		y = i / 8;
		xpos = x * square_size + square_size / 2;
		ypos = y * square_size + square_size / 2;
		if((x % 2) ^ (y % 2))
		{
			cairo_set_source_rgb(cr, 0, 0, 0);
			cairo_rectangle(cr, xpos, ypos, square_size, square_size);
			cairo_fill(cr);
		}
		else
		{
			cairo_set_source_rgb(cr, 255, 255, 255);
			cairo_rectangle(cr, xpos, ypos, square_size, square_size);
			cairo_fill(cr);
		}
	}
	cairo_move_to(cr, 20, square_size * 9);
	cairo_set_source_rgb(cr, 0, 0, 0);
	cairo_show_text(cr, out);
	if(cairo_status(cr))
	{
		printf("Cairo is unhappy: %s\n", 
			cairo_status_to_string(cairo_status(cr)));
		exit(ERROR);
	}
	cairo_destroy(cr);
	cairo_surface_destroy(surface);
}

void output_init(void)
{
	Window root;
	memset(&boardWindow, 0, sizeof(boardWindow));
	board_create();

	boardWindow.width = 360;
	boardWindow.height = 440;

	root = DefaultRootWindow(boardWindow.dpy);
	boardWindow.scr = DefaultScreen(boardWindow.dpy);
	boardWindow.win = XCreateSimpleWindow(boardWindow.dpy, 
		root, 0, 0, boardWindow.width, boardWindow.height, 0, 
		BlackPixel(boardWindow.dpy, boardWindow.scr), 
		BlackPixel(boardWindow.dpy, boardWindow.scr));
	boardWindow.quit_code = XKeysymToKeycode(boardWindow.dpy, 
		XStringToKeysym("Q"));

	XSelectInput(boardWindow.dpy, boardWindow.win, 
		KeyPressMask|StructureNotifyMask|ExposureMask);

	XMapWindow(boardWindow.dpy, boardWindow.win);

	board_redraw(&boardWindow);
}

void output(void)
{
	XEvent xev;

	board_redraw();

	while(true)
	{
		putchar('.');
		XNextEvent(boardWindow.dpy, &xev);
		switch(xev.type)
		{
			case KeyPress:
				{
					XKeyEvent *kev = &xev.xkey;

					if(kev->keycode == boardWindow.quit_code)
					{
						exit(QUIT);
					}
					else if(kev->keycode == XKeysymToKeycode(boardWindow.dpy,
						XK_Return))
						return;
				}
				break;
			case ConfigureNotify:
				{
					XConfigureEvent *cev = &xev.xconfigure;

					boardWindow.width = cev->width;
					boardWindow.height = cev->height;
				}
				break;
			case Expose:
				{
					XExposeEvent *eev = &xev.xexpose;

					if(eev->count == 0)
					{
						board_redraw(&boardWindow);
					}
				}
				break;
		}
	}
	putchar('\n');
}