#include <wayland-client-protocol.h>
#include <assert.h>
#include <string.h>
#include <wayland-client.h>
#include <xkbcommon/xkbcommon.h>
#include <sys/mman.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <poll.h>
#include <fcntl.h>
#include <errno.h>
#include <malloc.h>
#include <arpa/inet.h>

#include "drw.h"
#include "util.h"
#include "wayland.h"

/* type definitions */
typedef struct BG BG;
struct BG {
	unsigned width;
	unsigned height;
	uint32_t registry_name;
	Canvas *canvas;
	struct wl_output *wl_output;
	struct wl_surface *wl_surface;
	struct zwlr_layer_surface_v1 *zwlr_surface;
	BG *next;
};

typedef struct {
	uint32_t width;
	uint32_t height;
	uint32_t *buffer;
} Image;

/* function declarations */
static void update_bg(BG *bg);
static void wl_buffer_release(void *data, struct wl_buffer *wl_buffer);
static void remove_bg(BG *bg);
static void registry_global(void *data, struct wl_registry *wl_registry, uint32_t name, const char *interface, uint32_t version);
static void remove_global(void *data, struct wl_registry *wl_registry, uint32_t name);
static void layer_surface_configure(void *data, struct zwlr_layer_surface_v1 *surface, uint32_t serial, uint32_t w, uint32_t h);
static void layer_surface_closed(void *data, struct zwlr_layer_surface_v1 *surface);
static void dummy();
static void wayland_flush();
static void register_bg(BG *bg);
static void readimage();
static void setup();
struct wl_buffer *draw_frame(BG *bg);
static BG *add_bg();


/* global variables */
static const struct wl_buffer_listener wl_buffer_listener = {
	.release = wl_buffer_release,
};

static const struct wl_registry_listener wl_registry_listener = {
	.global = registry_global,
	.global_remove = remove_global,
};

static const struct zwlr_layer_surface_v1_listener layer_surface_listener = {
	.configure = layer_surface_configure,
	.closed = layer_surface_closed
};

static BG *bgs = NULL;
static char statusline[1024] = "";
struct client_state bg_state = { 0 };
struct pollfd pollfds[2];
int displayfd;
int ready = 0;
Image img;

/* configuration */
#include "config.h"

/* function implementations */
void
wl_buffer_release(void *data, struct wl_buffer *wl_buffer)
{
	wl_buffer_destroy(wl_buffer);
}


struct wl_buffer *
draw_frame(BG *bg)
{

	Canvas *canvas = bg->canvas;
	unsigned tx;
	unsigned ty;
	unsigned x;
	unsigned y;
	Color c;
	Color colbg = to_color(background);
	double strength;

	if (canvas == 0)
		return 0;

	draw_rect(canvas, 0, 0, bg->width, bg->height, background); 

	tx = (bg->width - img.width) / 2;
	ty = (bg->height - img.height) / 2;

	for (x = 0; x < img.width; ++x) {
		for (y = 0; y < img.height; ++y) {
			c = to_color(img.buffer[x + img.width * y]);
			strength = (double)(c.a) / 255;

			c.r = (strength * c.r) + ((1 - strength) * colbg.r);
			c.g = (strength * c.g) + ((1 - strength) * colbg.g);
			c.b = (strength * c.b) + ((1 - strength) * colbg.b);
			c.a = 0xff;

			draw_point(canvas, x + tx, y + ty, to_uint32_t(c));
		}
	}

	return canvas->buffer;
}

void
update_bg(BG *bg)
{
	struct wl_buffer *buffer = draw_frame(bg);

	if (!buffer)
		return;

	wl_surface_attach(bg->wl_surface, buffer, 0, 0);
	wl_surface_damage_buffer(bg->wl_surface, 0, 0, bg->width, bg->height);
	wl_surface_commit(bg->wl_surface);
}


void
registry_global(void *data, struct wl_registry *wl_registry, uint32_t name, const char *interface, uint32_t version)
{
	struct client_state *state = data;
	BG *bg;

	if (strcmp(interface, wl_shm_interface.name) == 0) {
		state->wl_shm = wl_registry_bind(
				wl_registry, name, &wl_shm_interface, 1);
	} else if (strcmp(interface, wl_compositor_interface.name) == 0) {
		state->wl_compositor = wl_registry_bind(
				wl_registry, name, &wl_compositor_interface, 4);
	} else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
		state->zwlr_layer = wl_registry_bind(wl_registry, name, &zwlr_layer_shell_v1_interface, 1);
	} else if (strcmp(interface, wl_output_interface.name) == 0) {
		bg = add_bg();
		bg->wl_output = wl_registry_bind(wl_registry, name, &wl_output_interface, 1);
		bg->registry_name = name;

		if (ready) {
			register_bg(bg);
		}
	}
}


void
remove_global(void *data, struct wl_registry *wl_registry, uint32_t name)
{
	BG *bg = bgs;
	BG *prev = 0;

	for (; bg; bg = bg->next) {
		if (bg->registry_name == name) {
			if (prev) {
				prev->next = bg->next;
			} else {
				bgs = bg->next;
			}

			remove_bg(bg);
			break;
		}

		prev = bg;
	}
}


void
layer_surface_configure(void *data, struct zwlr_layer_surface_v1 *surface, uint32_t serial, uint32_t w, uint32_t h)
{
	BG *bg = data;

	bg->width = w;
	bg->height = h;

	zwlr_layer_surface_v1_set_exclusive_zone(surface, -1);
	zwlr_layer_surface_v1_ack_configure(surface, serial);

	if (bg->canvas != 0) {
		free_drw(bg->canvas);
	}

	bg->canvas = create_drw(bg_state.wl_shm, bg->width, bg->height);

	update_bg(bg);
}


void
layer_surface_closed(void *data, struct zwlr_layer_surface_v1 *surface)
{
	BG *bg = data;
	zwlr_layer_surface_v1_destroy(surface);
	wl_surface_destroy(bg->wl_surface);
}


void
dummy()
{
	/* Who cares */
}


BG *
add_bg()
{
	BG *bg = bgs;

	if (!bg) {
		bgs = malloc(sizeof(BG));
		memset(bgs, 0, sizeof(BG));
		return bgs;
	}

	for (; bg->next; bg = bg->next);

	bg->next = malloc(sizeof(BG));
	memset(bg->next, 0, sizeof(BG));

	return bg->next;
}


void
remove_bg(BG *bg)
{
	wl_surface_destroy(bg->wl_surface);
	zwlr_layer_surface_v1_destroy(bg->zwlr_surface);
	wl_output_destroy(bg->wl_output);
	free_drw(bg->canvas);
	free(bg);
}	


void
register_bg(BG *bg)
{
	char *namespace = "dbg";
	uint32_t layer = ZWLR_LAYER_SHELL_V1_LAYER_BACKGROUND;
	uint32_t anchor = ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM | ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;

	bg->wl_surface = wl_compositor_create_surface(bg_state.wl_compositor);
	bg->zwlr_surface = zwlr_layer_shell_v1_get_layer_surface(bg_state.zwlr_layer, bg->wl_surface, bg->wl_output, layer, namespace);

	zwlr_layer_surface_v1_add_listener(bg->zwlr_surface, &layer_surface_listener, bg);

	zwlr_layer_surface_v1_set_size(bg->zwlr_surface, bg->width, bg->height);
	zwlr_layer_surface_v1_set_anchor(bg->zwlr_surface, anchor);

	wl_surface_commit(bg->wl_surface);
	wl_display_roundtrip(bg_state.wl_display);
}

void
readimage()
{
	uint32_t buf[4];
	size_t i;
	size_t s = 0;
	uint8_t r, g, b, a;
	uint64_t *tmpbuf;
	uint64_t color;
	read(STDIN_FILENO, buf, sizeof(buf));

	if (memcmp(buf, "farbfeld", sizeof("farbfeld") - 1)) {
		die("input not farbfeld image");
	}

	img.width = ntohl(buf[2]);
	img.height = ntohl(buf[3]);
	img.buffer = malloc(img.width * img.height * sizeof(uint32_t));
	tmpbuf = malloc(img.width * img.height * sizeof(uint64_t));

	for (i = 0; i < ((size_t)img.width * img.height * sizeof(uint64_t));) {
		i += read(STDIN_FILENO, (char*)(tmpbuf) + i, 1);
	}

	for (i = 0; i < img.width * img.height; ++i) {
		color = tmpbuf[i];
		a = ((color & (0xffffl << 48)) >> 48) / 257;
		b = ((color & (0xffffl << 32)) >> 32) / 257;
		g = ((color & (0xffffl << 16)) >> 16) / 257;
		r = (color & 0xffffl) / 257;
		img.buffer[i] = (a << 24) | (r << 16) | (g << 8) | b;
	}

	free(tmpbuf);
}


void
setup()
{
	BG *bg;

	bg_state.wl_display = wl_display_connect(NULL);
	bg_state.wl_registry = wl_display_get_registry(bg_state.wl_display);
	wl_registry_add_listener(bg_state.wl_registry, &wl_registry_listener, &bg_state);
	wl_display_roundtrip(bg_state.wl_display);

	for (bg = bgs; bg; bg = bg->next) {
		register_bg(bg);
	}

	ready = 1;
}


void
wayland_flush()
{
	int i;

	wl_display_dispatch_pending(bg_state.wl_display);

	if (wl_display_flush(bg_state.wl_display) < 0 && errno == EAGAIN) {
		for (i = 0; i < 2; ++i) {
			if (pollfds[i].fd == displayfd) {
				pollfds[i].events |= POLLOUT;
			}
		}
	}
}


int
main(int argc, char *argv[])
{
	readimage();
	setup();

	while (wl_display_dispatch(bg_state.wl_display)) {
	}

	return 0;
}