#include <stdlib.h>
#include <assert.h>
#include <math.h>

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_CACHE_H

#include "lib/window.h"
#include "lib/graphics.h"

sprite_t * sprites[128];
sprite_t alpha_tmp;

uint16_t win_width;
uint16_t win_height;

int center_x(int x) {
	return (win_width - x) / 2;
}

int center_y(int y) {
	return (win_height - y) / 2;
}

void init_sprite(int i, char * filename, char * alpha) {
	sprites[i] = malloc(sizeof(sprite_t));
	load_sprite(sprites[i], filename);
	if (alpha) {
		sprites[i]->alpha = 1;
		load_sprite(&alpha_tmp, alpha);
		sprites[i]->masks = alpha_tmp.bitmap;
	} else {
		sprites[i]->alpha = 0;
	}
	sprites[i]->blank = 0x0;
}

int32_t min(int32_t a, int32_t b) {
	return (a < b) ? a : b;
}

int32_t max(int32_t a, int32_t b) {
	return (a > b) ? a : b;
}

/* Bilinear filtering from Wikipedia */
uint32_t getBilinearFilteredPixelColor(sprite_t * tex, double u, double v) {
	u *= tex->width;
	v *= tex->height;
	int x = floor(u);
	int y = floor(v);
	if (x >= tex->width)  return 0;
	if (y >= tex->height) return 0;
	double u_ratio = u - x;
	double v_ratio = v - y;
	double u_o = 1 - u_ratio;
	double v_o = 1 - v_ratio;
	double r_ALP = 256;
	if (tex->alpha) {
		if (x == tex->width - 1 || y == tex->height - 1) return (SPRITE(tex,x,y) | 0xFF000000) & (0xFFFFFF + _RED(SMASKS(tex,x,y)) * 0x1000000);
		r_ALP = (_RED(SMASKS(tex,x,y)) * u_o + _RED(SMASKS(tex,x+1,y)) * u_ratio) * v_o + (_RED(SMASKS(tex,x,y+1)) * u_o  + _RED(SMASKS(tex,x+1,y+1)) * u_ratio) * v_ratio;
	}
	if (x == tex->width - 1 || y == tex->height - 1) return SPRITE(tex,x,y);
	double r_RED = (_RED(SPRITE(tex,x,y)) * u_o + _RED(SPRITE(tex,x+1,y)) * u_ratio) * v_o + (_RED(SPRITE(tex,x,y+1)) * u_o  + _RED(SPRITE(tex,x+1,y+1)) * u_ratio) * v_ratio;
	double r_BLU = (_BLU(SPRITE(tex,x,y)) * u_o + _BLU(SPRITE(tex,x+1,y)) * u_ratio) * v_o + (_BLU(SPRITE(tex,x,y+1)) * u_o  + _BLU(SPRITE(tex,x+1,y+1)) * u_ratio) * v_ratio;
	double r_GRE = (_GRE(SPRITE(tex,x,y)) * u_o + _GRE(SPRITE(tex,x+1,y)) * u_ratio) * v_o + (_GRE(SPRITE(tex,x,y+1)) * u_o  + _GRE(SPRITE(tex,x+1,y+1)) * u_ratio) * v_ratio;

	return rgb(r_RED,r_GRE,r_BLU) & (0xFFFFFF + (int)r_ALP * 0x1000000);
}

void draw_sprite_scaled(sprite_t * sprite, uint16_t x, uint16_t y, uint16_t width, uint16_t height) {
	int32_t _left   = max(x, 0);
	int32_t _top    = max(y, 0);
	int32_t _right  = min(x + width,  graphics_width - 1);
	int32_t _bottom = min(y + height, graphics_height - 1);
	for (uint16_t _y = 0; _y < height; ++_y) {
		for (uint16_t _x = 0; _x < width; ++_x) {
			if (x + _x < _left || x + _x > _right || y + _y < _top || y + _y > _bottom)
				continue;
			if (sprite->alpha) {
				uint32_t n_color = getBilinearFilteredPixelColor(sprite, (double)_x / (double)width, (double)_y/(double)height);
				uint32_t f_color = rgb(_ALP(n_color), 0, 0);
				GFX(x + _x, y + _y) = alpha_blend(GFX(x + _x, y + _y), n_color, f_color);
			} else {
				GFX(x + _x, y + _y) = getBilinearFilteredPixelColor(sprite, (double)_x / (double)width, (double)_y/(double)height);
			}
		}
	}
}

int main (int argc, char ** argv) {
	setup_windowing();

	int width  = wins_globals->server_width;
	int height = wins_globals->server_height;

	win_width = width;
	win_height = height;


	/* Do something with a window */
	window_t * wina = window_create(0,0, width, height);
	assert(wina);
	window_fill(wina, rgb(100,100,100));
	window_reorder (wina, 0);
	init_graphics_window_double_buffer(wina);
	window_redraw_full(wina);

#if 1
	printf("Loading background...\n");
	init_sprite(0, "/usr/share/login-background.bmp", NULL);
	printf("Background loaded.\n");
	draw_sprite_scaled(sprites[0], 0, 0, width, height);
#endif

#if 0
	init_sprite(1, "/usr/share/bs.bmp", "/usr/share/bs-alpha.bmp");
	draw_sprite_scaled(sprites[1], center_x(sprites[1]->width), center_y(sprites[1]->height), sprites[1]->width, sprites[1]->height);
#endif

	flip();
	window_redraw_full(wina);

	while (1) {
		syscall_yield();
		//syscall_wait(wins_globals->server_pid);
	}


#if 0
	window_destroy(window); // (will close on exit)
	teardown_windowing();
#endif

	return 0;
}