module;

#include <errno.h>
#include <fcntl.h>
#include <linux/input.h>
#include <string>
#include <sys/mman.h>
#include <unistd.h>
#include <wayland-cursor.h>
#include <xkbcommon/xkbcommon.h>
#include <iostream>
#include <vulkan/vulkan.h>
#include <vulkan/vulkan_wayland.h>
#include <wayland-client.h>
#include <cstring>
#include "xdg-shell-client-protocol.h"
#include "wayland-xdg-decoration-unstable-v1-client-protocol.h"
#define _POSIX_C_SOURCE 200809L
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/mman.h>
#include <time.h>
#include <unistd.h>
#include <print>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>
#include <wayland-client.h>
#include <wayland-client-protocol.h>
#include <linux/input-event-codes.h>
#include <cmath>


module Crafter.Graphics;
import Crafter.Event;
using namespace Crafter;

static void xdg_wm_base_handle_ping(void* data, xdg_wm_base* xdg_wm_base, std::uint32_t serial) {
	xdg_wm_base_pong(xdg_wm_base, serial);
}

xdg_wm_base_listener xdgWmBaseListener = {
.ping = xdg_wm_base_handle_ping,
};


void WindowWayland::pointer_handle_button(void* data, wl_pointer* pointer, std::uint32_t serial, std::uint32_t time, std::uint32_t button, std::uint32_t state) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	if (button == BTN_LEFT) {
		if(state == WL_POINTER_BUTTON_STATE_PRESSED) {
			window->mouseLeftHeld = true;
			window->onMouseLeftClick.Invoke(window->currentMousePos);	
		} else {
			window->mouseLeftHeld = false;
			window->onMouseLeftRelease.Invoke(window->currentMousePos);	
		}
	} else if(button == BTN_RIGHT){
		if(state == WL_POINTER_BUTTON_STATE_PRESSED) {
			window->mouseRightHeld = true;
			window->onMouseRightClick.Invoke(window->currentMousePos);	
		} else {
			window->mouseRightHeld = true;
			window->onMouseRightRelease.Invoke(window->currentMousePos);	
		}
	}
}

void WindowWayland::PointerListenerHandleMotion(void* data, wl_pointer* wl_pointer, uint time, wl_fixed_t surface_x, wl_fixed_t surface_y) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	MousePoint pos = {wl_fixed_to_double(surface_x), wl_fixed_to_double(surface_y)};
	window->lastMousePos = window->currentMousePos;
	window->currentMousePos = pos;
	window->mouseDelta = {window->currentMousePos.x-window->lastMousePos.x, window->currentMousePos.y-window->lastMousePos.y};
	window->onMouseMove.Invoke({window->lastMousePos, window->currentMousePos, window->mouseDelta});
}

void WindowWayland::PointerListenerHandleEnter(void* data, wl_pointer* wl_pointer, uint serial, wl_surface* surface, wl_fixed_t surface_x, wl_fixed_t surface_y) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	window->onMouseEnter.Invoke({window->lastMousePos, window->currentMousePos, window->mouseDelta});
}

void WindowWayland::PointerListenerHandleLeave(void* data, wl_pointer*, std::uint32_t, wl_surface*) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	window->onMouseEnter.Invoke({window->lastMousePos, window->currentMousePos, window->mouseDelta});
}

void WindowWayland::PointerListenerHandleAxis(void*, wl_pointer*, std::uint32_t, std::uint32_t, wl_fixed_t value) {
	std::cout << wl_fixed_to_double(value) << std::endl;
}

wl_pointer_listener WindowWayland::pointer_listener = {
.enter = WindowWayland::PointerListenerHandleEnter,
.leave = WindowWayland::PointerListenerHandleLeave,
.motion = WindowWayland::PointerListenerHandleMotion,
.button = WindowWayland::pointer_handle_button,
.axis = WindowWayland::PointerListenerHandleAxis,
};

void WindowWayland::seat_handle_capabilities(void* data, wl_seat* seat, uint32_t capabilities) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	window->seat = seat;
	if (capabilities & WL_SEAT_CAPABILITY_POINTER) {
		wl_pointer* pointer = wl_seat_get_pointer(seat);
		wl_pointer_add_listener(pointer, &pointer_listener, window);
	}
}

wl_seat_listener WindowWayland::seat_listener = {
.capabilities = seat_handle_capabilities,
};

void WindowWayland::handle_global(void *data, wl_registry *registry, std::uint32_t name, const char *interface, std::uint32_t version) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	if (strcmp(interface, wl_shm_interface.name) == 0) {
		window->shm = reinterpret_cast<wl_shm*>(wl_registry_bind(registry, name, &wl_shm_interface, 1));
	} else if (strcmp(interface, wl_seat_interface.name) == 0) {
		wl_seat* seat = reinterpret_cast<wl_seat*>(wl_registry_bind(registry, name, &wl_seat_interface, 1));
		wl_seat_add_listener(seat, &seat_listener, window);
	} else if (compositor == NULL && strcmp(interface, wl_compositor_interface.name) == 0) {
		compositor =  reinterpret_cast<wl_compositor*>(wl_registry_bind(registry, name, &wl_compositor_interface, 1));
	} else if (strcmp(interface, xdg_wm_base_interface.name) == 0) {
		window->xdgWmBase = reinterpret_cast<xdg_wm_base*>(wl_registry_bind(registry, name, &xdg_wm_base_interface, 1));
		xdg_wm_base_add_listener(window->xdgWmBase, &xdgWmBaseListener, NULL);
	} else if (strcmp(interface, zxdg_decoration_manager_v1_interface.name) == 0) {
		window->manager = reinterpret_cast<zxdg_decoration_manager_v1*>(wl_registry_bind(registry, name, &zxdg_decoration_manager_v1_interface, 1));
	}
}

static void handle_global_remove(void* data, wl_registry* registry, uint32_t name) {

	
}

wl_registry_listener WindowWayland::registry_listener = {
.global = WindowWayland::handle_global,
.global_remove = handle_global_remove,
};

static void noop5(void*, xdg_toplevel*, std::int32_t, std::int32_t, wl_array*){
	
}

void WindowWayland::xdg_toplevel_handle_close(void* data, xdg_toplevel*) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	window->onClose.Invoke();
	window->open = false;
}

xdg_toplevel_listener WindowWayland::xdg_toplevel_listener = {
.configure = noop5,
.close = WindowWayland::xdg_toplevel_handle_close,
};

void WindowWayland::xdg_surface_handle_configure(void* data, xdg_surface* xdg_surface, std::uint32_t serial) {
	WindowWayland* window = reinterpret_cast<WindowWayland*>(data);
	// The compositor configures our surface, acknowledge the configure event
	xdg_surface_ack_configure(xdg_surface, serial);

	if (window->configured) {
		// If this isn't the first configure event we've received, we already
		// have a buffer attached, so no need to do anything. Commit the
		// surface to apply the configure acknowledgement.
		wl_surface_commit(window->surface);
	}

	window->configured = true;
}

xdg_surface_listener WindowWayland::xdg_surface_listener = {
.configure = xdg_surface_handle_configure,
};

static void randname(char *buf) {
	struct timespec ts;
	clock_gettime(CLOCK_REALTIME, &ts);
	long r = ts.tv_nsec;
	for (int i = 0; i < 6; ++i) {
		buf[i] = 'A'+(r&15)+(r&16)*2;
		r >>= 5;
	}
}

static int anonymous_shm_open(void) {
	char name[] = "/hello-wayland-XXXXXX";
	int retries = 100;

	do {
		randname(name + strlen(name) - 6);

		--retries;
		// shm_open guarantees that O_CLOEXEC is set
		int fd = shm_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
		if (fd >= 0) {
			shm_unlink(name);
			return fd;
		}
	} while (retries > 0 && errno == EEXIST);

	return -1;
}

int create_shm_file(off_t size) {
	int fd = anonymous_shm_open();
	if (fd < 0) {
		return fd;
	}

	if (ftruncate(fd, size) < 0) {
		close(fd);
		return -1;
	}

	return fd;
}

WindowWayland::WindowWayland(std::string name, std::uint32_t width, std::uint32_t height) : Window(name, width, height) {
	// Connect to the Wayland compositor
	display = wl_display_connect(NULL);
	if (display == NULL) {
		std::cerr <<  "failed to create display" << std::endl;
	}
	// Obtain the wl_registry and fetch the list of globals
	wl_registry* registry = wl_display_get_registry(display);
	wl_registry_add_listener(registry, &registry_listener, this);
	if (wl_display_roundtrip(display) == -1) {
		exit(EXIT_FAILURE);
	}
	// Check that all globals we require are available
	if (shm == NULL || compositor == NULL || xdgWmBase == NULL) {
		std::cerr << "no wl_shm, wl_compositor or xdg_wm_base support" << std::endl;
		exit(EXIT_FAILURE);
	}

	// Create a wl_surface, a xdg_surface and a xdg_toplevel
	surface = wl_compositor_create_surface(compositor);
	xdgSurface = xdg_wm_base_get_xdg_surface(xdgWmBase, surface);
	xdgToplevel = xdg_surface_get_toplevel(xdgSurface);


	xdg_surface_add_listener(xdgSurface, &xdg_surface_listener, this);
	xdg_toplevel_add_listener(xdgToplevel, &xdg_toplevel_listener, this);
	wl_surface_commit(surface);

	while (wl_display_dispatch(display) != -1 && !configured) {
		// This space intentionally left blank
	}

	// Create a wl_buffer, attach it to the surface and commit the surface
	int stride = width * 4;
	int size = stride * height;

	// Allocate a shared memory file with the right size
	int fd = create_shm_file(size);
	if (fd < 0) {
		fprintf(stderr, "creating a buffer file for %d B failed: %m\n", size);
	}

	// Map the shared memory file
	shm_data = reinterpret_cast<Pixel_RU8_GU8_BU8_AU8*>(mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
	if (shm_data == MAP_FAILED) {
		fprintf(stderr, "mmap failed: %m\n");
		close(fd);
	}

	// Create a wl_buffer from our shared memory file descriptor
	wl_shm_pool *pool = wl_shm_create_pool(shm, fd, size);
	buffer = wl_shm_pool_create_buffer(pool, 0, width, height, stride, WL_SHM_FORMAT_ARGB8888);
	wl_shm_pool_destroy(pool);

	// Now that we've mapped the file and created the wl_buffer, we no longer
	// need to keep file descriptor opened
	close(fd);


	if (buffer == NULL) {
		exit(EXIT_FAILURE);
	}

	wl_surface_attach(surface, buffer, 0, 0);
	wl_surface_commit(surface);

	for(std::uint32_t x = 0; x < 128; x++) {
		for(std::uint32_t y = 0; y < 128; y++) {
			shm_data[x*128+y].r = 0;
			shm_data[x*128+y].g = 0;
			shm_data[x*128+y].b = 0;
			shm_data[x*128+y].a = 255;
		}
	}

	zxdg_toplevel_decoration_v1* decoration = zxdg_decoration_manager_v1_get_toplevel_decoration(manager, xdgToplevel); // toplevel is from xdg_surface_get_toplevel
	zxdg_toplevel_decoration_v1_set_mode(decoration, ZXDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
}

WindowWayland::~WindowWayland() {
	xdg_toplevel_destroy(xdgToplevel);
	xdg_surface_destroy(xdgSurface);
	wl_surface_destroy(surface);
	wl_buffer_destroy(buffer);
}