#include "App.hpp"

#include <algorithm>
#include <cassert>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <span>
#include <sys/mman.h>
#include <sys/signalfd.h>
#include <thread>
#include <unistd.h>
#include <unordered_set>
#include <vector>

#include <GLES3/gl3.h>
#include <fontconfig/fontconfig.h>
#include <glib.h>
#include <raylib.h>
#include <rlgl.h>
#include <xkbcommon/xkbcommon.h>

#define namespace namespace_
#include "wlr-layer-shell-unstable-v1-client-protocol.h"
#undef namespace

#include "blur-client-protocol.h"
#include "ext-background-effect-v1-client-protocol.h"

namespace {

constexpr usize MAX_SURROUNDING_BYTES = 4000;

inline auto is_utf8_continuation(char c) -> bool
{
	return (static_cast<unsigned char>(c) & 0xC0) == 0x80;
}

inline auto adjust_utf8_backward(std::string const &text, int index) -> int
{
	index = std::clamp(index, 0, static_cast<int>(text.size()));
	while (
	    index > 0 && is_utf8_continuation(text[static_cast<usize>(index - 1)]))
		--index;
	return index;
}

inline auto adjust_utf8_forward(std::string const &text, int index) -> int
{
	int const size = static_cast<int>(text.size());
	index = std::clamp(index, 0, size);
	while (
	    index < size && is_utf8_continuation(text[static_cast<usize>(index)]))
		++index;
	return index;
}

struct SurroundingSlice {
	std::string text;
	int cursor { 0 };
	int anchor { 0 };
};

auto clamp_surrounding_text(std::string const &text, int cursor, int anchor)
    -> SurroundingSlice
{
	int const size = static_cast<int>(text.size());
	cursor = std::clamp(cursor, 0, size);
	anchor = std::clamp(anchor, 0, size);

	if (text.size() <= MAX_SURROUNDING_BYTES) {
		return SurroundingSlice { text, cursor, anchor };
	}

	int window_start = std::max(0,
	    std::min(cursor, anchor) - static_cast<int>(MAX_SURROUNDING_BYTES / 2));
	int window_end = window_start + static_cast<int>(MAX_SURROUNDING_BYTES);
	int const max_pos = std::max(cursor, anchor);
	if (window_end < max_pos) {
		window_end = max_pos;
		window_start
		    = std::max(0, window_end - static_cast<int>(MAX_SURROUNDING_BYTES));
	}
	if (window_end > size)
		window_end = size;
	if (window_end - window_start > static_cast<int>(MAX_SURROUNDING_BYTES)) {
		window_start = window_end - static_cast<int>(MAX_SURROUNDING_BYTES);
	}

	window_start = adjust_utf8_backward(text, window_start);
	window_end = adjust_utf8_forward(text, window_end);
	if (window_end < window_start)
		window_end = window_start;

	std::string slice(text.begin() + window_start, text.begin() + window_end);
	int const new_cursor
	    = std::clamp(cursor - window_start, 0, static_cast<int>(slice.size()));
	int const new_anchor
	    = std::clamp(anchor - window_start, 0, static_cast<int>(slice.size()));

	return SurroundingSlice { std::move(slice), new_cursor, new_anchor };
}

} // namespace

auto TypingBuffer::push_utf8(char const *s) -> void
{
	for (unsigned char const *p = reinterpret_cast<unsigned char const *>(s);
	    *p;) {
		u32 cp = 0;
		int len = 0;
		if (*p < 0x80) {
			cp = *p++;
			len = 1;
		} else if ((*p & 0xE0) == 0xC0) {
			cp = *p++ & 0x1F;
			len = 2;
		} else if ((*p & 0xF0) == 0xE0) {
			cp = *p++ & 0x0F;
			len = 3;
		} else {
			cp = *p++ & 0x07;
			len = 4;
		}
		for (int i = 1; i < len; i++)
			cp = (cp << 6) | ((*p++) & 0x3F);
		push_back(cp);
	}
}

App::App()
{
	init_wayland();
	init_egl();
	init_signal();
	init_theme_portal();
}

App::~App()
{
	if (m_sfd != -1)
		close(m_sfd);

	destroy_layer_surface();

	if (m_gl.edpy != EGL_NO_DISPLAY) {
		if (m_gl.ectx != EGL_NO_CONTEXT)
			eglDestroyContext(m_gl.edpy, m_gl.ectx);
		eglTerminate(m_gl.edpy);
	}

	if (m_kbd.xkb_state_v)
		xkb_state_unref(m_kbd.xkb_state_v);
	if (m_kbd.xkb_keymap_v)
		xkb_keymap_unref(m_kbd.xkb_keymap_v);
	if (m_kbd.xkb_ctx_v)
		xkb_context_unref(m_kbd.xkb_ctx_v);
	if (m_wayland.text_input) {
		zwp_text_input_v3_destroy(m_wayland.text_input);
		m_wayland.text_input = nullptr;
	}
	if (m_wayland.text_input_mgr) {
		zwp_text_input_manager_v3_destroy(m_wayland.text_input_mgr);
		m_wayland.text_input_mgr = nullptr;
	}
	if (m_wayland.kbd)
		wl_keyboard_destroy(m_wayland.kbd);
	if (m_wayland.seat)
		wl_seat_destroy(m_wayland.seat);
	if (m_wayland.compositor)
		wl_compositor_destroy(m_wayland.compositor);
	if (m_wayland.registry)
		wl_registry_destroy(m_wayland.registry);
	if (m_wayland.display)
		wl_display_disconnect(m_wayland.display);

	if (m_xdp.settings)
		g_object_unref(m_xdp.settings);
	if (m_xdp.portal)
		g_object_unref(m_xdp.portal);
}

auto App::run() -> void
{
	SetWindowSize(m_win_w, m_win_h);
	while (m_running) {
		pump_events();
		tick();
		m_kbd.typing.clear();
		m_kbd.clear_transients();
		std::this_thread::sleep_for(std::chrono::milliseconds(16));
	}
}

auto App::set_visible(bool visible) -> void
{
	if (visible == m_visible)
		return;

	if (visible) {
		create_layer_surface();
		ensure_egl_surface();
	} else {
		destroy_layer_surface();
	}

	if (m_wayland.display)
		wl_display_flush(m_wayland.display);
}

auto App::init_wayland() -> void
{
	m_wayland.display = wl_display_connect(nullptr);
	if (!m_wayland.display) {
		std::fprintf(stderr, "failed to connect to Wayland display\n");
		std::exit(EXIT_FAILURE);
	}

	static wl_keyboard_listener keyboard_listener {};
	{
		auto kb_keymap { [](void *data, wl_keyboard *, u32 format, i32 fd,
			                 u32 size) -> void {
			auto *app { static_cast<App *>(data) };
			if (format != WL_KEYBOARD_KEYMAP_FORMAT_XKB_V1) {
				close(fd);
				return;
			}
			void *map = mmap(nullptr, size, PROT_READ, MAP_PRIVATE, fd, 0);
			if (map == MAP_FAILED) {
				close(fd);
				return;
			}
			if (app->m_kbd.xkb_keymap_v)
				xkb_keymap_unref(app->m_kbd.xkb_keymap_v);
			if (app->m_kbd.xkb_state_v) {
				xkb_state_unref(app->m_kbd.xkb_state_v);
				app->m_kbd.xkb_state_v = nullptr;
			}
			app->m_kbd.xkb_keymap_v = xkb_keymap_new_from_string(
			    app->m_kbd.xkb_ctx_v, static_cast<char const *>(map),
			    XKB_KEYMAP_FORMAT_TEXT_V1, XKB_KEYMAP_COMPILE_NO_FLAGS);
			app->m_kbd.xkb_state_v = app->m_kbd.xkb_keymap_v
			    ? xkb_state_new(app->m_kbd.xkb_keymap_v)
			    : nullptr;
			munmap(map, size);
			close(fd);
		} };

		auto kb_enter { [](void *data, wl_keyboard *, u32 serial, wl_surface *,
			                wl_array *) -> void {
			static_cast<App *>(data)->m_last_serial = serial;
		} };
		auto kb_leave
		    = [](void *data, wl_keyboard *, u32, wl_surface *) -> void {
			static_cast<App *>(data)->m_kbd.held.clear();
		};

		auto kb_key { [](void *data, wl_keyboard *, u32 serial, u32, u32 key,
			              u32 state) -> void {
			auto *app { static_cast<App *>(data) };
			if (!app->m_kbd.xkb_state_v)
				return;

			app->m_last_serial = serial;

			xkb_keycode_t kc = key + 8;

			if (state == WL_KEYBOARD_KEY_STATE_PRESSED) {
				app->m_kbd.held.insert(key);

				xkb_state_update_key(app->m_kbd.xkb_state_v, kc, XKB_KEY_DOWN);
				xkb_keysym_t sym
				    = xkb_state_key_get_one_sym(app->m_kbd.xkb_state_v, kc);
				app->m_kbd.pressed_syms.insert(sym);

				bool ctrl = app->m_kbd.mod_active("Control");
				bool alt = app->m_kbd.mod_active("Mod1");
				bool meta = app->m_kbd.mod_active("Mod4");

				bool handled = false;
				switch (sym) {
				case XKB_KEY_Left:
					app->m_kbd.typing.push_back(1);
					handled = true;
					break;
				case XKB_KEY_Down:
					app->m_kbd.typing.push_back(2);
					handled = true;
					break;
				case XKB_KEY_Up:
					app->m_kbd.typing.push_back(3);
					handled = true;
					break;
				case XKB_KEY_Right:
					app->m_kbd.typing.push_back(4);
					handled = true;
					break;
				case XKB_KEY_BackSpace:
					app->m_kbd.typing.push_back(8);
					handled = true;
					break;
				case XKB_KEY_Delete:
				case XKB_KEY_KP_Delete:
					app->m_kbd.typing.push_back(0x7F);
					handled = true;
					break;
				case XKB_KEY_Return:
				case XKB_KEY_KP_Enter:
					app->m_kbd.typing.push_back('\n');
					handled = true;
					break;
				case XKB_KEY_v:
				case XKB_KEY_V:
					app->m_kbd.typing.push_back('v');
					handled = true;
					break;
				case XKB_KEY_c:
				case XKB_KEY_C:
					app->m_kbd.typing.push_back('c');
					handled = true;
					break;
				case XKB_KEY_w:
				case XKB_KEY_W:
					if (ctrl) {
						app->m_kbd.typing.push_back(8);
						handled = true;
					}
					break;
				default:
					break;
				}

				if (!handled && !(ctrl || alt || meta)) {
					u32 cp = xkb_keysym_to_utf32(sym);
					if (cp >= 0x20) {
						char buf[8];
						int n = xkb_keysym_to_utf8(sym, buf, sizeof(buf));
						if (n > 0)
							app->m_kbd.typing.push_utf8(buf);
					}
				}
			} else {
				xkb_keysym_t sym
				    = xkb_state_key_get_one_sym(app->m_kbd.xkb_state_v, kc);
				app->m_kbd.released_syms.insert(sym);

				app->m_kbd.held.erase(key);
				xkb_state_update_key(app->m_kbd.xkb_state_v, kc, XKB_KEY_UP);
			}
		} };

		auto kb_mods { [](void *data, wl_keyboard *, u32, u32 depressed,
			               u32 latched, u32 locked, u32 group) -> void {
			auto *app { static_cast<App *>(data) };
			if (!app->m_kbd.xkb_state_v)
				return;
			xkb_state_update_mask(app->m_kbd.xkb_state_v, depressed, latched,
			    locked, 0, 0, group);
		} };

		auto kb_repeat_info { [](void *, wl_keyboard *, i32, i32) -> void { } };

		keyboard_listener = { kb_keymap, kb_enter, kb_leave, kb_key, kb_mods,
			kb_repeat_info };
	}

	static zwp_text_input_v3_listener text_input_listener {};
	{
		auto ti_enter
		    = [](void *data, zwp_text_input_v3 *, wl_surface *surface) -> void {
			auto *app { static_cast<App *>(data) };
			bool const focused_surface
			    = surface && surface == app->m_wayland.surface;
			app->m_ime.seat_focus = focused_surface;
			app->m_ime.pending = {};
			app->m_ime.pending_done = false;
			if (!focused_surface) {
				app->m_ime.enabled = false;
				app->m_ime.last_surrounding.clear();
				if (app->m_gui)
					app->m_gui->ime_clear_preedit();
			} else {
				app->m_ime.surrounding_dirty = true;
			}
		};

		auto ti_leave { [](void *data, zwp_text_input_v3 *,
			                wl_surface *) -> void {
			auto *app { static_cast<App *>(data) };
			app->m_ime.seat_focus = false;
			app->m_ime.enabled = false;
			app->m_ime.pending = {};
			app->m_ime.pending_done = false;
			app->m_ime.last_surrounding.clear();
			if (app->m_gui)
				app->m_gui->ime_clear_preedit();
		} };

		auto ti_preedit { [](void *data, zwp_text_input_v3 *, char const *text,
			                  int32_t cursor_begin,
			                  int32_t cursor_end) -> void {
			auto *app { static_cast<App *>(data) };
			auto &pending { app->m_ime.pending };
			pending.has_preedit = true;
			pending.preedit_text = text ? text : "";
			pending.cursor_begin = cursor_begin;
			pending.cursor_end = cursor_end;
		} };

		auto ti_commit { [](void *data, zwp_text_input_v3 *,
			                 char const *text) -> void {
			auto *app { static_cast<App *>(data) };
			auto &pending { app->m_ime.pending };
			pending.has_commit = true;
			pending.commit_text = text ? text : "";
		} };

		auto ti_delete { [](void *data, zwp_text_input_v3 *, uint32_t before,
			                 uint32_t after) -> void {
			auto *app { static_cast<App *>(data) };
			auto &pending { app->m_ime.pending };
			pending.has_delete = true;
			pending.before = before;
			pending.after = after;
		} };

		auto ti_done
		    = [](void *data, zwp_text_input_v3 *, uint32_t serial) -> void {
			auto *app { static_cast<App *>(data) };
			app->m_ime.pending_done = true;
			app->m_ime.pending_serial = serial;
			app->m_ime.surrounding_dirty = true;
		};

		text_input_listener
		    = { ti_enter, ti_leave, ti_preedit, ti_commit, ti_delete, ti_done };
	}

	static auto ensure_text_input { +[](App *app) -> void {
		if (!app->m_wayland.text_input_mgr || !app->m_wayland.seat
		    || app->m_wayland.text_input)
			return;
		app->m_wayland.text_input = zwp_text_input_manager_v3_get_text_input(
		    app->m_wayland.text_input_mgr, app->m_wayland.seat);
		if (!app->m_wayland.text_input)
			return;
		zwp_text_input_v3_add_listener(
		    app->m_wayland.text_input, &text_input_listener, app);
		app->m_ime.supported = true;
		app->m_ime.enabled = false;
		app->m_ime.last_surrounding.clear();
		app->m_ime.sent_serial = 0;
	} };

	auto handle_registry_global
	    = [](void *data, wl_registry *registry, u32 name, char const *interface,
	          u32 version) -> void {
		auto *app { static_cast<App *>(data) };
		if (std::strcmp(interface, wl_compositor_interface.name) == 0) {
			app->m_wayland.compositor = static_cast<wl_compositor *>(
			    wl_registry_bind(registry, name, &wl_compositor_interface, 4));
		} else if (std::strcmp(interface, wl_seat_interface.name) == 0) {
			app->m_wayland.seat = static_cast<wl_seat *>(
			    wl_registry_bind(registry, name, &wl_seat_interface, 9));
			static struct wl_seat_listener const seat_listener = {
				.capabilities =
				    [](void *data, struct wl_seat *seat, u32 caps) {
				        auto *app { static_cast<App *>(data) };
				        if (caps & WL_SEAT_CAPABILITY_KEYBOARD) {
					        app->m_wayland.kbd = wl_seat_get_keyboard(seat);
					        wl_keyboard_add_listener(
					            app->m_wayland.kbd, &keyboard_listener, data);
					        app->m_ime.seat_focus = false;
				        }
				        ensure_text_input(app);
				    },
				.name = [](void *, struct wl_seat *, char const *) {},
			};
			wl_seat_add_listener(app->m_wayland.seat, &seat_listener, data);
		} else if (std::strcmp(interface, zwlr_layer_shell_v1_interface.name)
		    == 0) {
			app->m_wayland.layer_shell = static_cast<zwlr_layer_shell_v1 *>(
			    wl_registry_bind(registry, name, &zwlr_layer_shell_v1_interface,
			        version >= 4 ? 4 : version));
		} else if (std::strcmp(interface,
		               ext_background_effect_manager_v1_interface.name)
		    == 0) {
			app->m_wayland.mgr
			    = static_cast<ext_background_effect_manager_v1 *>(
			        wl_registry_bind(registry, name,
			            &ext_background_effect_manager_v1_interface, 1));
		} else if (std::strcmp(interface, "org_kde_kwin_blur_manager") == 0) {
			app->m_wayland.kde_blur_mgr
			    = static_cast<org_kde_kwin_blur_manager *>(wl_registry_bind(
			        registry, name, &org_kde_kwin_blur_manager_interface, 1));
		} else if (std::strcmp(
		               interface, zwp_text_input_manager_v3_interface.name)
		    == 0) {
			app->m_wayland.text_input_mgr
			    = static_cast<zwp_text_input_manager_v3 *>(wl_registry_bind(
			        registry, name, &zwp_text_input_manager_v3_interface, 1));
			app->m_ime.supported = true;
			ensure_text_input(app);
		} else if (std::strcmp(interface, wl_data_device_manager_interface.name)
		    == 0) {
			app->m_wayland.ddm
			    = static_cast<wl_data_device_manager *>(wl_registry_bind(
			        registry, name, &wl_data_device_manager_interface,
			        std::min<uint32_t>(version, 3)));
			if (app->m_wayland.ddm && !app->m_wayland.ddev) {
				app->m_wayland.ddev = wl_data_device_manager_get_data_device(
				    app->m_wayland.ddm, app->m_wayland.seat);
				static wl_data_device_listener const ddev_l = {
					.data_offer =
					    [](void *data, wl_data_device *, wl_data_offer *offer) {
					        auto *app = static_cast<App *>(data);
					        static wl_data_offer_listener const offer_l = {
						        .offer =
						            [](void *data, wl_data_offer *,
						                char const *mime) {
						                auto *app = static_cast<App *>(data);
						                (void)app;
						                (void)mime;
						            },
#if WL_DATA_OFFER_SOURCE_ACTIONS_SINCE_VERSION
						        .source_actions
						        = [](void *, wl_data_offer *, uint32_t) {},
						        .action
						        = [](void *, wl_data_offer *, uint32_t) {}
#endif
					        };
					        wl_data_offer_add_listener(offer, &offer_l, app);
					        if (app->m_wayland.curr_offer
					            && app->m_wayland.curr_offer != offer)
						        wl_data_offer_destroy(
						            app->m_wayland.curr_offer);
					        app->m_wayland.curr_offer = offer;
					    },
					.enter
					= [](void *, wl_data_device *, uint32_t, wl_surface *,
					      wl_fixed_t, wl_fixed_t, wl_data_offer *) {},
					.leave = [](void *, wl_data_device *) {},
					.motion = [](void *, wl_data_device *, uint32_t, wl_fixed_t,
					              wl_fixed_t) {},
					.drop = [](void *, wl_data_device *) {},
					.selection =
					    [](void *data, wl_data_device *, wl_data_offer *offer) {
					        auto *app = static_cast<App *>(data);
					        if (!offer) {
						        app->m_clipboard_cache.clear();
						        return;
					        }

					        char const *mime = "text/plain;charset=utf-8";
					        int fds[2];
					        if (pipe(fds) != 0)
						        return;

					        wl_data_offer_receive(offer, mime, fds[1]);
					        wl_display_flush(app->m_wayland.display);
					        close(fds[1]);

					        int rfd = fds[0];

					        std::thread([app, rfd, offer]() {
						        std::string data;
						        char buf[4096];
						        for (;;) {
							        ssize_t n = read(rfd, buf, sizeof buf);
							        if (n > 0) {
								        data.append(buf, buf + n);
								        continue;
							        }
							        if (n < 0 && errno == EINTR)
								        continue;
							        break;
						        }
						        close(rfd);

						        struct Ctx {
							        App *app;
							        wl_data_offer *offer;
							        std::string data;
						        };
						        auto *ctx
						            = new Ctx { app, offer, std::move(data) };

						        g_main_context_invoke(
						            nullptr,
						            +[](gpointer p) -> gboolean {
							            auto *ctx = static_cast<Ctx *>(p);
							            if (!ctx->data.empty())
								            ctx->app->m_clipboard_cache
								                = std::move(ctx->data);
							            wl_data_offer_destroy(ctx->offer);
							            delete ctx;
							            return G_SOURCE_REMOVE;
						            },
						            ctx);
					        }).detach();
					    },
				};
				wl_data_device_add_listener(app->m_wayland.ddev, &ddev_l, app);
			}
		}
	};

	static wl_registry_listener const registry_listener {
		.global = handle_registry_global,
		.global_remove = [](void *, wl_registry *, u32) { },
	};

	m_wayland.registry = wl_display_get_registry(m_wayland.display);
	wl_registry_add_listener(m_wayland.registry, &registry_listener, this);

	m_kbd.xkb_ctx_v = xkb_context_new(XKB_CONTEXT_NO_FLAGS);

	wl_display_roundtrip(m_wayland.display);

	create_layer_surface();
}

auto App::init_egl() -> void
{
	m_gl.edpy = eglGetDisplay(
	    reinterpret_cast<EGLNativeDisplayType>(m_wayland.display));
	eglInitialize(m_gl.edpy, nullptr, nullptr);

	EGLint const cfgAttribs[] { EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT, EGL_RED_SIZE, 8,
		EGL_GREEN_SIZE, 8, EGL_BLUE_SIZE, 8, EGL_ALPHA_SIZE, 8, EGL_NONE };
	EGLint n = 0;
	eglChooseConfig(m_gl.edpy, cfgAttribs, &m_gl.ecfg, 1, &n);

	EGLint const ctxAttribs[] = { EGL_CONTEXT_MAJOR_VERSION, 2, EGL_NONE };
	m_gl.ectx
	    = eglCreateContext(m_gl.edpy, m_gl.ecfg, EGL_NO_CONTEXT, ctxAttribs);

	ensure_egl_surface();

	InitWindow(m_win_w, m_win_h, "");

	m_tr = std::make_shared<TextRenderer>();
	m_gui = std::make_shared<ImGui>(m_tr);
	auto const font { find_font_path() };
	assert(font && "Could not find font");
	std::vector<std::filesystem::path> fallback_paths;
	std::unordered_set<std::string> seen_paths;
	auto const primary_path_str { font->string() };

	constexpr char const *fallback_candidates[] = {
		"Noto Sans CJK JP:style=Regular",
		"Noto Sans CJK SC:style=Regular",
		"Noto Sans CJK KR:style=Regular",
		"Noto Sans CJK TC:style=Regular",
		"sans-serif:lang=ja",
		"sans-serif:lang=ko",
		"sans-serif:lang=zh-cn",
		"sans-serif:lang=zh-tw",
		"sans-serif:lang=zh-hk",
		"Noto Color Emoji:style=Regular",
	};
	for (auto const *name : fallback_candidates) {
		if (auto fallback { find_font_path(name) }) {
			auto const path_str { fallback->string() };
			if (path_str == primary_path_str)
				continue;
			if (!seen_paths.emplace(path_str).second)
				continue;
			fallback_paths.push_back(*fallback);
		}
	}
	if (fallback_paths.empty()) {
		TraceLog(LOG_WARNING,
		    "No fallback fonts found; some glyphs may render as missing");
	}
	auto const font_handle { m_tr->load_font(
		*font, std::span(fallback_paths)) };
	assert(font_handle && "Could not load font");
	m_font = *font_handle;
	m_gui->set_font(m_font);
}

auto App::init_signal() -> void
{
	sigset_t mask;
	sigemptyset(&mask);
	sigaddset(&mask, SIGUSR1);

	if (pthread_sigmask(SIG_BLOCK, &mask, nullptr) != 0) {
		std::perror("pthread_sigmask");
		std::exit(EXIT_FAILURE);
	}

	m_sfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
	if (m_sfd == -1) {
		std::perror("signalfd");
		std::exit(EXIT_FAILURE);
	}
}

void App::on_settings_changed(XdpSettings * /*self*/, char const *ns,
    char const *key, GVariant * /*value*/, gpointer data)
{
	auto *app { static_cast<App *>(data) };
	if (g_strcmp0(ns, "org.freedesktop.appearance") == 0) {
		if (g_strcmp0(key, "color-scheme") == 0) {
			guint v = xdp_settings_read_uint(app->m_xdp.settings,
			    "org.freedesktop.appearance", "color-scheme", NULL, NULL);

			if (v == 1)
				app->m_active_theme = Theme::Dark;
			else
				app->m_active_theme = Theme::Light;
		} else if (g_strcmp0(key, "accent-color") == 0) {
			auto val { xdp_settings_read_value(app->m_xdp.settings,
				"org.freedesktop.appearance", "accent-color", NULL, NULL) };
			if (val) {
				gdouble r, g, b;
				g_variant_get(val, "(ddd)", &r, &g, &b);
				app->m_accent_color.r = static_cast<u8>(r * 255);
				app->m_accent_color.g = static_cast<u8>(g * 255);
				app->m_accent_color.b = static_cast<u8>(b * 255);
				g_variant_unref(val);
			}
		}
	}
}

auto App::init_theme_portal() -> void
{
	m_xdp.portal = xdp_portal_new();
	m_xdp.settings = xdp_portal_get_settings(m_xdp.portal);

	guint v = xdp_settings_read_uint(m_xdp.settings,
	    "org.freedesktop.appearance", "color-scheme", NULL, NULL);
	if (v == 1)
		m_active_theme = Theme::Dark;
	else
		m_active_theme = Theme::Light;

	auto val { xdp_settings_read_value(m_xdp.settings,
		"org.freedesktop.appearance", "accent-color", NULL, NULL) };
	if (val) {
		gdouble r, g, b;
		g_variant_get(val, "(ddd)", &r, &g, &b);
		m_accent_color.r = static_cast<u8>(r * 255);
		m_accent_color.g = static_cast<u8>(g * 255);
		m_accent_color.b = static_cast<u8>(b * 255);
		g_variant_unref(val);
	}

	g_signal_connect(
	    m_xdp.settings, "changed", G_CALLBACK(on_settings_changed), this);
}

auto App::create_layer_surface() -> void
{
	if (m_wayland.layer_surface)
		return;

	if (!m_wayland.compositor || !m_wayland.layer_shell)
		return;

	m_wayland.surface = wl_compositor_create_surface(m_wayland.compositor);

	if (m_wayland.mgr) {
		m_wayland.eff = ext_background_effect_manager_v1_get_background_effect(
		    m_wayland.mgr, m_wayland.surface);
	}
	if (m_wayland.kde_blur_mgr) {
		m_wayland.kde_blur = org_kde_kwin_blur_manager_create(
		    m_wayland.kde_blur_mgr, m_wayland.surface);
	}

	m_wayland.layer_surface = zwlr_layer_shell_v1_get_layer_surface(
	    m_wayland.layer_shell, m_wayland.surface, nullptr,
	    ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY, "waylight-overlay");

	if (!m_wayland.layer_surface) {
		if (m_wayland.eff) {
			ext_background_effect_surface_v1_destroy(m_wayland.eff);
			m_wayland.eff = nullptr;
		}
		if (m_wayland.kde_blur) {
			org_kde_kwin_blur_destroy(m_wayland.kde_blur);
			m_wayland.kde_blur = nullptr;
		}
		if (m_wayland.surface) {
			wl_surface_destroy(m_wayland.surface);
			m_wayland.surface = nullptr;
		}
		return;
	}

	zwlr_layer_surface_v1_set_anchor(m_wayland.layer_surface, 0);
	zwlr_layer_surface_v1_set_size(m_wayland.layer_surface, m_win_w, m_win_h);
	zwlr_layer_surface_v1_set_exclusive_zone(m_wayland.layer_surface, 0);

	if (zwlr_layer_shell_v1_get_version(m_wayland.layer_shell) >= 3) {
		zwlr_layer_surface_v1_set_keyboard_interactivity(
		    m_wayland.layer_surface,
		    ZWLR_LAYER_SURFACE_V1_KEYBOARD_INTERACTIVITY_ON_DEMAND);
	}

	auto handle_layer_configure { [](void *data, zwlr_layer_surface_v1 *ls,
		                              u32 serial, u32 w, u32 h) -> void {
		auto *app { static_cast<App *>(data) };
		if (w)
			app->m_win_w = static_cast<int>(w);
		if (h)
			app->m_win_h = static_cast<int>(h);

		zwlr_layer_surface_v1_ack_configure(ls, serial);

		if (app->m_gl.edpy != EGL_NO_DISPLAY) {
			if (!app->m_gl.wegl || app->m_gl.esurf == EGL_NO_SURFACE) {
				app->ensure_egl_surface();
			} else {
				wl_egl_window_resize(
				    app->m_gl.wegl, app->m_win_w, app->m_win_h, 0, 0);
				eglMakeCurrent(app->m_gl.edpy, app->m_gl.esurf, app->m_gl.esurf,
				    app->m_gl.ectx);
			}
		}

		app->update_blur_region();

		if (app->m_wayland.surface)
			wl_surface_commit(app->m_wayland.surface);
	} };

	auto handle_layer_closed { [](void *data, zwlr_layer_surface_v1 *) -> void {
		static_cast<App *>(data)->m_running = false;
	} };

	static zwlr_layer_surface_v1_listener const lsl = {
		.configure = handle_layer_configure,
		.closed = handle_layer_closed,
	};

	zwlr_layer_surface_v1_add_listener(m_wayland.layer_surface, &lsl, this);

	update_blur_region();

	if (m_wayland.surface)
		wl_surface_commit(m_wayland.surface);

	if (m_wayland.display)
		wl_display_roundtrip(m_wayland.display);

	ensure_egl_surface();

	m_visible = true;
}

auto App::destroy_layer_surface() -> void
{
	if (m_gl.edpy != EGL_NO_DISPLAY && m_gl.esurf != EGL_NO_SURFACE) {
		eglMakeCurrent(
		    m_gl.edpy, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
		eglDestroySurface(m_gl.edpy, m_gl.esurf);
		m_gl.esurf = EGL_NO_SURFACE;
	}

	if (m_gl.wegl) {
		wl_egl_window_destroy(m_gl.wegl);
		m_gl.wegl = nullptr;
	}

	if (m_wayland.eff) {
		ext_background_effect_surface_v1_destroy(m_wayland.eff);
		m_wayland.eff = nullptr;
	}

	if (m_wayland.kde_blur) {
		org_kde_kwin_blur_destroy(m_wayland.kde_blur);
		m_wayland.kde_blur = nullptr;
	}

	if (m_wayland.layer_surface) {
		zwlr_layer_surface_v1_destroy(m_wayland.layer_surface);
		m_wayland.layer_surface = nullptr;
	}

	if (m_wayland.surface) {
		wl_surface_destroy(m_wayland.surface);
		m_wayland.surface = nullptr;
	}

	if (m_wayland.display)
		wl_display_flush(m_wayland.display);

	m_visible = false;
}

auto App::ensure_egl_surface() -> void
{
	if (m_gl.edpy == EGL_NO_DISPLAY || m_gl.ectx == EGL_NO_CONTEXT)
		return;
	if (!m_wayland.surface)
		return;

	if (!m_gl.wegl)
		m_gl.wegl = wl_egl_window_create(m_wayland.surface, m_win_w, m_win_h);

	if (!m_gl.wegl)
		return;

	if (m_gl.esurf == EGL_NO_SURFACE) {
		m_gl.esurf = eglCreateWindowSurface(m_gl.edpy, m_gl.ecfg,
		    reinterpret_cast<EGLNativeWindowType>(m_gl.wegl), nullptr);
	}

	if (m_gl.esurf == EGL_NO_SURFACE)
		return;

	eglMakeCurrent(m_gl.edpy, m_gl.esurf, m_gl.esurf, m_gl.ectx);
	eglSwapInterval(m_gl.edpy, 1);
}

auto App::update_blur_region() -> void
{
	if (!m_wayland.compositor)
		return;
	if (!m_wayland.eff && !m_wayland.kde_blur)
		return;

	wl_region *region = wl_compositor_create_region(m_wayland.compositor);
	if (!region)
		return;

	wl_region_add(region, 0, 0, m_win_w - 50, m_win_h);

	if (m_wayland.eff)
		ext_background_effect_surface_v1_set_blur_region(m_wayland.eff, region);
	if (m_wayland.kde_blur)
		org_kde_kwin_blur_set_region(m_wayland.kde_blur, region);

	wl_region_destroy(region);
}

auto App::process_pending_text_input() -> void
{
	if (!m_ime.pending_done)
		return;
	if (!m_gui)
		return;
	if (!m_ime.bound_text)
		return;
	if (!m_wayland.text_input)
		return;

	auto focused { m_gui->focused_text_input() };
	if (!focused || *focused != m_ime.bound_id) {
		m_ime.pending = {};
		m_ime.pending_done = false;
		return;
	}

	m_gui->ime_clear_preedit();

	if (m_ime.pending.has_delete) {
		m_gui->ime_delete_surrounding(
		    *m_ime.bound_text, m_ime.pending.before, m_ime.pending.after);
	}

	if (m_ime.pending.has_commit) {
		m_gui->ime_commit_text(*m_ime.bound_text, m_ime.pending.commit_text);
	}

	if (m_ime.pending.has_preedit) {
		m_gui->ime_set_preedit(m_ime.pending.preedit_text,
		    m_ime.pending.cursor_begin, m_ime.pending.cursor_end);
	} else {
		m_gui->ime_clear_preedit();
	}

	m_ime.pending = {};
	m_ime.pending_done = false;
	m_ime.surrounding_dirty = true;
}

auto App::update_text_input_state(
    std::pmr::string const &text, usize id, Rectangle field_rect) -> void
{
	if (!m_wayland.text_input || !m_ime.supported || !m_gui)
		return;

	m_ime.bound_rect = field_rect;

	auto focused { m_gui->focused_text_input() };
	bool const has_focus { focused && (*focused == id) };
	bool const should_enable { has_focus && m_ime.seat_focus };

	if (!should_enable) {
		if (m_ime.enabled) {
			zwp_text_input_v3_disable(m_wayland.text_input);
			zwp_text_input_v3_commit(m_wayland.text_input);
			m_ime.sent_serial++;
			m_ime.enabled = false;
			m_ime.last_surrounding.clear();
		}
		return;
	}

	bool state_dirty = false;

	if (!m_ime.enabled) {
		zwp_text_input_v3_enable(m_wayland.text_input);
		zwp_text_input_v3_set_content_type(m_wayland.text_input,
		    ZWP_TEXT_INPUT_V3_CONTENT_HINT_NONE,
		    ZWP_TEXT_INPUT_V3_CONTENT_PURPOSE_NORMAL);
		m_ime.enabled = true;
		m_ime.surrounding_dirty = true;
		state_dirty = true;
	}

	if (auto info { m_gui->text_input_surrounding(id, text) }) {
		auto slice
		    = clamp_surrounding_text(info->text, info->cursor, info->anchor);
		if (m_ime.surrounding_dirty || slice.text != m_ime.last_surrounding
		    || slice.cursor != m_ime.last_cursor
		    || slice.anchor != m_ime.last_anchor) {
			zwp_text_input_v3_set_surrounding_text(m_wayland.text_input,
			    slice.text.c_str(), slice.cursor, slice.anchor);
			m_ime.last_surrounding = std::move(slice.text);
			m_ime.last_cursor = slice.cursor;
			m_ime.last_anchor = slice.anchor;
			state_dirty = true;
		}
	}

	if (auto cursor_info { m_gui->text_input_cursor(id) }) {
		Rectangle rect = cursor_info->rect;
		int32_t const x = static_cast<int32_t>(std::round(rect.x));
		int32_t const y = static_cast<int32_t>(std::round(rect.y));
		int32_t const width
		    = std::max(1, static_cast<int32_t>(std::round(rect.width)));
		int32_t const height
		    = std::max(1, static_cast<int32_t>(std::round(rect.height)));
		bool const visible = cursor_info->visible;

		if (rect.x != m_ime.last_cursor_rect.x
		    || rect.y != m_ime.last_cursor_rect.y
		    || rect.width != m_ime.last_cursor_rect.width
		    || rect.height != m_ime.last_cursor_rect.height
		    || visible != m_ime.last_cursor_visible) {
			zwp_text_input_v3_set_cursor_rectangle(
			    m_wayland.text_input, x, y, width, height);
			m_ime.last_cursor_rect = rect;
			m_ime.last_cursor_visible = visible;
			state_dirty = true;
		}
	}

	if (state_dirty) {
		zwp_text_input_v3_commit(m_wayland.text_input);
		m_ime.sent_serial++;
		m_ime.surrounding_dirty = false;
	}
}

auto App::pump_events() -> void
{
	while (g_main_context_iteration(nullptr, false))
		;

	wl_display_dispatch_pending(m_wayland.display);
	wl_display_flush(m_wayland.display);

	pollfd fds[2] { { wl_display_get_fd(m_wayland.display), POLLIN, 0 },
		{ m_sfd, POLLIN, 0 } };

	auto prepared { (wl_display_prepare_read(m_wayland.display) == 0) };
	auto ret { poll(fds, 2, 0) };

	if (ret > 0 && (fds[0].revents & POLLIN)) {
		if (prepared) {
			wl_display_read_events(m_wayland.display);
			prepared = false;
		}
	} else if (prepared) {
		wl_display_cancel_read(m_wayland.display);
	}

	if (ret > 0 && (fds[1].revents & POLLIN)) {
		signalfd_siginfo si;
		while (read(m_sfd, &si, sizeof(si)) == sizeof(si)) {
			if (si.ssi_signo == SIGUSR1) {
				set_visible(!visible());
			}
		}
	}
}

auto App::clipboard(std::string_view const &str) -> void
{
	if (!m_wayland.ddm || !m_wayland.ddev || !m_wayland.seat)
		return;
	if (m_last_serial == 0)
		return;

	if (m_wayland.curr_source) {
		wl_data_source_destroy(m_wayland.curr_source);
		m_wayland.curr_source = nullptr;
	}
	m_wayland.curr_source
	    = wl_data_device_manager_create_data_source(m_wayland.ddm);

	static wl_data_source_listener const src_l = {
		.target = [](void *, wl_data_source *, char const *) {},
		.send =
		    [](void *data, wl_data_source *, char const *, int32_t fd) {
		        auto *app = static_cast<App *>(data);

		        int wfd = dup(fd);
		        close(fd);

		        std::pmr::string payload = app->m_clipboard_cache;
		        std::thread([wfd, payload = std::move(payload)]() {
			        size_t off = 0;
			        while (off < payload.size()) {
				        ssize_t n = write(wfd, payload.data() + off,
				            std::min<size_t>(64 * 1024, payload.size() - off));
				        if (n > 0) {
					        off += (size_t)n;
					        continue;
				        }
				        if (n < 0 && (errno == EINTR))
					        continue;
				        if (n < 0 && (errno == EAGAIN)) {
					        std::this_thread::sleep_for(
					            std::chrono::milliseconds(1));
					        continue;
				        }
				        break;
			        }
			        close(wfd);
		        }).detach();
		    },
		.cancelled =
		    [](void *data, wl_data_source *src) {
		        auto *app = static_cast<App *>(data);
		        if (app->m_wayland.curr_source == src)
			        app->m_wayland.curr_source = nullptr;
		        wl_data_source_destroy(src);
		    },
#if WL_DATA_SOURCE_DND_DROP_PERFORMED_SINCE_VERSION
		.dnd_drop_performed = [](void *, wl_data_source *) {},
		.dnd_finished = [](void *, wl_data_source *) {},
		.action = [](void *, wl_data_source *, uint32_t) {}
#endif
	};
	wl_data_source_add_listener(m_wayland.curr_source, &src_l, this);
	wl_data_source_offer(m_wayland.curr_source, "text/plain;charset=utf-8");
	wl_data_source_offer(m_wayland.curr_source, "text/plain");

	m_clipboard_cache.assign(str.begin(), str.end());

	wl_data_device_set_selection(
	    m_wayland.ddev, m_wayland.curr_source, m_last_serial);
	wl_display_flush(m_wayland.display);
}