/*
 * X11 GUI for slide puzzle game
 * Copyright © 2022 Nick Bowler
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdio.h>
#include <assert.h>
#include <Xm/XmStrDefs.h>
#include "motif.h"

/* TODO user-selectable colours */
static const char * const colours[][3] = {
	/*primary    bottom      top */
	"#8d2e28", "#6a1b17", "#a14842", /* red */
	"#b46e28", "#924a16", "#c7904f", /* orange */
	"#d8b740", "#c59f39", "#e2c65d", /* yellow */
	"#286428", "#194719", "#4e874e", /* green */
	"#003471", "#001f4f", "#00528b", /* blue */
	"#dcdcdc", "#c0c0c0", "#eaeaea", /* white */
};

static void init_colours(struct app_state *state, Screen *screen)
{
	Display *display = DisplayOfScreen(screen);
	Colormap cmap = DefaultColormapOfScreen(screen);
	XColor colour, junk;
	unsigned i, j;

	for (j = 0; j < COLOUR_MAX; j++) {
		for (i = 0; i < TILE_MAX-1; i++) {
			XAllocNamedColor(display, cmap, colours[i][j],
			                          &colour, &junk);
			state->tile_colour[i][j] = colour.pixel;
		}
	}
}

void x11_initialize(struct app_state *state, Screen *screen)
{
	Display *display = DisplayOfScreen(screen);
	Window root = RootWindowOfScreen(screen);
	Colormap cmap = DefaultColormapOfScreen(screen);
	XGCValues gcv;

	init_colours(state, screen);

	gcv.line_width = 1;
	state->tile_gc = XCreateGC(display, root, GCLineWidth, &gcv);
}

static void draw_tile(struct app_state *state, Display *display, Drawable d,
                      int tile, int gx, int gy, Dimension tw, Dimension th)
{
	int tx = gx * tw, ty = gy * th;

	XSegment topshadow[] = {
		{ tx,      ty,      tx,      ty+th   },
		{ tx+1,    ty,      tx+tw,   ty      },

		{ tx+1,    ty+1,    tx+1,    ty+th-1 },
		{ tx+2,    ty+1,    tx+tw-1, ty+1    }
	};

	XSegment bottomshadow[] = {
		{ tx+1,    ty+th-1, tx+tw,   ty+th-1 },
		{ tx+tw-1, ty+th-1, tx+tw-1, ty+1    },

		{ tx+2,    ty+th-2, tx+tw-1, ty+th-2 },
		{ tx+tw-2, ty+th-2, tx+tw-2, ty+2    }
	};

	XSetForeground(display, state->tile_gc, state->tile_colour[tile-1][COLOUR_LIGHT]);
	XDrawSegments(display, d, state->tile_gc, topshadow, XtNumber(topshadow));

	XSetForeground(display, state->tile_gc, state->tile_colour[tile-1][COLOUR_DARK]);
	XDrawSegments(display, d, state->tile_gc, bottomshadow, XtNumber(bottomshadow));

	XSetForeground(display, state->tile_gc, state->tile_colour[tile-1][COLOUR_PRIMARY]);
	XFillRectangle(display, d, state->tile_gc, tx+2, ty+2, tw-4, th-4);
}

static void
redraw_tile(struct app_state *state, Display *display, Drawable d,
            uint_fast32_t bit0, uint_fast32_t bit1, uint_fast32_t bit2,
            int x, int y, Dimension w, Dimension h)
{
	uint_fast32_t pos = board_position(x, y);
	unsigned char tile = 0;

	if (bit0 & pos) tile |= 1;
	if (bit1 & pos) tile |= 2;
	if (bit2 & pos) tile |= 4;
	assert(tile < TILE_MAX);

	if (tile == TILE_EMPTY) {
		XClearArea(display, d, x*w, y*h, w, h, 0);
	} else {
		draw_tile(state, display, d, tile, x, y, w, h);
	}
}

void x11_redraw_goal(struct app_state *state)
{
	Display *display = XtDisplay(state->goal);
	Window goal = XtWindow(state->goal);
	Dimension w, h;
	int i;

	XtVaGetValues(state->goal, XmNwidth, &w, XmNheight, &h, (char *)NULL);
	w /= 3; h /= 3;

	for (i = 0; i < 9; i++) {
		uint_least16_t *gp = state->board.goal;

		redraw_tile(state, display, goal,
		            gp[0], gp[1], gp[2],
		            i%3, i/3, w, h);
	}
}

void x11_redraw_game(struct app_state *state)
{
	Display *display = XtDisplay(state->goal);
	Window game = XtWindow(state->game);
	Dimension w, h;
	int i;

	XtVaGetValues(state->game, XmNwidth, &w, XmNheight, &h, (char *)NULL);
	w /= 5; h /= 5;

	for (i = 0; i < 25; i++) {
		uint_least32_t *gp = state->board.game;

		redraw_tile(state, display, game,
		            gp[0], gp[1], gp[2],
		            i%5, i/5, w, h);
	}
}