#define _POSIX_C_SOURCE 200809L
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#include <wayland-client.h>
#include <wayland-cursor.h>
#include "config.h"
#include "swaybar/bar.h"
#include "swaybar/config.h"
#include "swaybar/i3bar.h"
#include "swaybar/input.h"
#include "swaybar/ipc.h"
#include "swaybar/status_line.h"
#include "swaybar/render.h"
#if HAVE_TRAY
#include "swaybar/tray/tray.h"
#endif
#include "ipc-client.h"
#include "list.h"
#include "log.h"
#include "loop.h"
#include "pool-buffer.h"
#include "wlr-layer-shell-unstable-v1-client-protocol.h"
#include "xdg-output-unstable-v1-client-protocol.h"

void free_workspaces(struct wl_list *list) {
	struct swaybar_workspace *ws, *tmp;
	wl_list_for_each_safe(ws, tmp, list, link) {
		wl_list_remove(&ws->link);
		free(ws->name);
		free(ws->label);
		free(ws);
	}
}

static void swaybar_output_free(struct swaybar_output *output) {
	if (!output) {
		return;
	}
	sway_log(SWAY_DEBUG, "Removing output %s", output->name);
	if (output->layer_surface != NULL) {
		zwlr_layer_surface_v1_destroy(output->layer_surface);
	}
	if (output->surface != NULL) {
		wl_surface_destroy(output->surface);
	}
	wl_output_destroy(output->output);
	destroy_buffer(&output->buffers[0]);
	destroy_buffer(&output->buffers[1]);
	free_hotspots(&output->hotspots);
	free_workspaces(&output->workspaces);
	wl_list_remove(&output->link);
	free(output->name);
	free(output->identifier);
	free(output);
}

static void set_output_dirty(struct swaybar_output *output) {
	if (output->frame_scheduled) {
		output->dirty = true;
	} else if (output->surface) {
		render_frame(output);
	}
}

static void layer_surface_configure(void *data,
		struct zwlr_layer_surface_v1 *surface,
		uint32_t serial, uint32_t width, uint32_t height) {
	struct swaybar_output *output = data;
	output->width = width;
	output->height = height;
	zwlr_layer_surface_v1_ack_configure(surface, serial);
	set_output_dirty(output);
}

static void layer_surface_closed(void *_output,
		struct zwlr_layer_surface_v1 *surface) {
	struct swaybar_output *output = _output;
	swaybar_output_free(output);
}

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

static void add_layer_surface(struct swaybar_output *output) {
	if (output->layer_surface) {
		return;
	}
	struct swaybar *bar = output->bar;

	struct swaybar_config *config = bar->config;
	bool hidden = strcmp(config->mode, "hide") == 0;
	bool overlay = !hidden && strcmp(config->mode, "overlay") == 0;
	output->layer_surface = zwlr_layer_shell_v1_get_layer_surface(
			bar->layer_shell, output->surface, output->output,
			hidden || overlay ? ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY :
			ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM, "panel");
	assert(output->layer_surface);
	zwlr_layer_surface_v1_add_listener(output->layer_surface,
			&layer_surface_listener, output);

	if (overlay) {
		// Empty input region
		struct wl_region *region = wl_compositor_create_region(bar->compositor);
		wl_surface_set_input_region(output->surface, region);
		wl_region_destroy(region);
	}

	zwlr_layer_surface_v1_set_anchor(output->layer_surface, config->position);
	if (hidden || overlay) {
		zwlr_layer_surface_v1_set_exclusive_zone(output->layer_surface, -1);
	}
}

void destroy_layer_surface(struct swaybar_output *output) {
	if (!output->layer_surface) {
		return;
	}
	zwlr_layer_surface_v1_destroy(output->layer_surface);
	wl_surface_attach(output->surface, NULL, 0, 0); // detach buffer
	output->layer_surface = NULL;
	output->width = 0;
	output->frame_scheduled = false;
}

void set_bar_dirty(struct swaybar *bar) {
	struct swaybar_output *output;
	wl_list_for_each(output, &bar->outputs, link) {
		set_output_dirty(output);
	}
}

bool determine_bar_visibility(struct swaybar *bar, bool moving_layer) {
	struct swaybar_config *config = bar->config;
	bool visible = !(strcmp(config->mode, "invisible") == 0 ||
		(strcmp(config->mode, config->hidden_state) == 0 // both "hide"
			&& !bar->visible_by_modifier && !bar->visible_by_urgency
			&& !bar->visible_by_mode));

	// Create/destroy layer surfaces as needed
	struct swaybar_output *output;
	wl_list_for_each(output, &bar->outputs, link) {
		// When moving to a different layer, we need to destroy and re-create
		// the layer surface
		if (!visible || moving_layer) {
			destroy_layer_surface(output);
		}

		if (visible) {
			add_layer_surface(output);
		}
	}
	set_bar_dirty(bar);

	if (visible != bar->visible) {
		bar->visible = visible;

		if (bar->status) {
			sway_log(SWAY_DEBUG, "Sending %s signal to status command",
					visible ? "cont" : "stop");
			kill(-bar->status->pid, visible ?
					bar->status->cont_signal : bar->status->stop_signal);
		}
	}

	return visible;
}

static bool bar_uses_output(struct swaybar_output *output) {
	if (wl_list_empty(&output->bar->config->outputs)) {
		return true;
	}
	char *identifier = output->identifier;
	struct config_output *coutput;
	wl_list_for_each(coutput, &output->bar->config->outputs, link) {
		if (strcmp(coutput->name, output->name) == 0 ||
				(identifier && strcmp(coutput->name, identifier) == 0)) {
			return true;
		}
	}
	return false;
}

static void output_geometry(void *data, struct wl_output *wl_output, int32_t x,
		int32_t y, int32_t width_mm, int32_t height_mm, int32_t subpixel,
		const char *make, const char *model, int32_t transform) {
	struct swaybar_output *output = data;
	output->subpixel = subpixel;
}

static void output_mode(void *data, struct wl_output *wl_output, uint32_t flags,
		int32_t width, int32_t height, int32_t refresh) {
	// Who cares
}

static void output_done(void *data, struct wl_output *wl_output) {
	struct swaybar_output *output = data;
	set_output_dirty(output);
}

static void output_scale(void *data, struct wl_output *wl_output,
		int32_t factor) {
	struct swaybar_output *output = data;
	output->scale = factor;

	bool render = false;
	struct swaybar_seat *seat;
	wl_list_for_each(seat, &output->bar->seats, link) {
		if (output == seat->pointer.current) {
			update_cursor(seat);
			render = true;
		}
	};
	if (render) {
		render_frame(output);
	}
}

static const struct wl_output_listener output_listener = {
	.geometry = output_geometry,
	.mode = output_mode,
	.done = output_done,
	.scale = output_scale,
};

static void xdg_output_handle_logical_position(void *data,
		struct zxdg_output_v1 *xdg_output, int32_t x, int32_t y) {
	struct swaybar_output *output = data;
	output->output_x = x;
	output->output_y = y;
}

static void xdg_output_handle_logical_size(void *data,
		struct zxdg_output_v1 *xdg_output, int32_t width, int32_t height) {
	struct swaybar_output *output = data;
	output->output_height = height;
	output->output_width = width;
}

static void xdg_output_handle_done(void *data,
		struct zxdg_output_v1 *xdg_output) {
	struct swaybar_output *output = data;
	struct swaybar *bar = output->bar;

	if (!wl_list_empty(&output->link)) {
		return;
	}

	assert(output->name != NULL);
	if (!bar_uses_output(output)) {
		wl_list_remove(&output->link);
		wl_list_insert(&bar->unused_outputs, &output->link);
		return;
	}

	wl_list_remove(&output->link);
	wl_list_insert(&bar->outputs, &output->link);

	output->surface = wl_compositor_create_surface(bar->compositor);
	assert(output->surface);

	determine_bar_visibility(bar, false);

	if (bar->running && bar->config->workspace_buttons) {
		ipc_get_workspaces(bar);
	}
}

static void xdg_output_handle_name(void *data,
		struct zxdg_output_v1 *xdg_output, const char *name) {
	struct swaybar_output *output = data;
	free(output->name);
	output->name = strdup(name);
}

static void xdg_output_handle_description(void *data,
		struct zxdg_output_v1 *xdg_output, const char *description) {
	// wlroots currently sets the description to `make model serial (name)`
	// If this changes in the future, this will need to be modified.
	struct swaybar_output *output = data;
	free(output->identifier);
	output->identifier = NULL;
	char *paren = strrchr(description, '(');
	if (paren) {
		size_t length = paren - description;
		output->identifier = malloc(length);
		if (!output->identifier) {
			sway_log(SWAY_ERROR, "Failed to allocate output identifier");
			return;
		}
		strncpy(output->identifier, description, length);
		output->identifier[length - 1] = '\0';
	}
}

static const struct zxdg_output_v1_listener xdg_output_listener = {
	.logical_position = xdg_output_handle_logical_position,
	.logical_size = xdg_output_handle_logical_size,
	.done = xdg_output_handle_done,
	.name = xdg_output_handle_name,
	.description = xdg_output_handle_description,
};

static void add_xdg_output(struct swaybar_output *output) {
	if (output->xdg_output != NULL) {
		return;
	}
	assert(output->bar->xdg_output_manager != NULL);
	output->xdg_output = zxdg_output_manager_v1_get_xdg_output(
		output->bar->xdg_output_manager, output->output);
	zxdg_output_v1_add_listener(output->xdg_output, &xdg_output_listener,
		output);
}

static void handle_global(void *data, struct wl_registry *registry,
		uint32_t name, const char *interface, uint32_t version) {
	struct swaybar *bar = data;
	if (strcmp(interface, wl_compositor_interface.name) == 0) {
		bar->compositor = wl_registry_bind(registry, name,
				&wl_compositor_interface, 4);
	} else if (strcmp(interface, wl_seat_interface.name) == 0) {
		struct swaybar_seat *seat = calloc(1, sizeof(struct swaybar_seat));
		if (!seat) {
			sway_abort("Failed to allocate swaybar_seat");
			return;
		}
		seat->bar = bar;
		seat->wl_name = name;
		seat->wl_seat = wl_registry_bind(registry, name, &wl_seat_interface, 5);
		wl_seat_add_listener(seat->wl_seat, &seat_listener, seat);
		wl_list_insert(&bar->seats, &seat->link);
	} else if (strcmp(interface, wl_shm_interface.name) == 0) {
		bar->shm = wl_registry_bind(registry, name,
				&wl_shm_interface, 1);
	} else if (strcmp(interface, wl_output_interface.name) == 0) {
		struct swaybar_output *output =
			calloc(1, sizeof(struct swaybar_output));
		output->bar = bar;
		output->output = wl_registry_bind(registry, name,
				&wl_output_interface, 3);
		wl_output_add_listener(output->output, &output_listener, output);
		output->scale = 1;
		output->wl_name = name;
		wl_list_init(&output->workspaces);
		wl_list_init(&output->hotspots);
		wl_list_init(&output->link);
		if (bar->xdg_output_manager != NULL) {
			add_xdg_output(output);
		}
	} else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
		bar->layer_shell = wl_registry_bind(
				registry, name, &zwlr_layer_shell_v1_interface, 1);
	} else if (strcmp(interface, zxdg_output_manager_v1_interface.name) == 0) {
		bar->xdg_output_manager = wl_registry_bind(registry, name,
			&zxdg_output_manager_v1_interface, 2);
	}
}

static void handle_global_remove(void *data, struct wl_registry *registry,
		uint32_t name) {
	struct swaybar *bar = data;
	struct swaybar_output *output, *tmp;
	wl_list_for_each_safe(output, tmp, &bar->outputs, link) {
		if (output->wl_name == name) {
			swaybar_output_free(output);
			return;
		}
	}
	wl_list_for_each_safe(output, tmp, &bar->unused_outputs, link) {
		if (output->wl_name == name) {
			swaybar_output_free(output);
			return;
		}
	}
	struct swaybar_seat *seat, *tmp_seat;
	wl_list_for_each_safe(seat, tmp_seat, &bar->seats, link) {
		if (seat->wl_name == name) {
			swaybar_seat_free(seat);
			return;
		}
	}
}

static const struct wl_registry_listener registry_listener = {
	.global = handle_global,
	.global_remove = handle_global_remove,
};

bool bar_setup(struct swaybar *bar, const char *socket_path) {
	bar->visible = true;
	bar->config = init_config();
	wl_list_init(&bar->outputs);
	wl_list_init(&bar->unused_outputs);
	wl_list_init(&bar->seats);
	bar->eventloop = loop_create();

	bar->ipc_socketfd = ipc_open_socket(socket_path);
	bar->ipc_event_socketfd = ipc_open_socket(socket_path);
	if (!ipc_initialize(bar)) {
		return false;
	}

	bar->display = wl_display_connect(NULL);
	if (!bar->display) {
		sway_abort("Unable to connect to the compositor. "
				"If your compositor is running, check or set the "
				"WAYLAND_DISPLAY environment variable.");
	}

	struct wl_registry *registry = wl_display_get_registry(bar->display);
	wl_registry_add_listener(registry, &registry_listener, bar);
	wl_display_roundtrip(bar->display);
	assert(bar->compositor && bar->layer_shell && bar->shm &&
		bar->xdg_output_manager);

	// Second roundtrip for xdg-output
	wl_display_roundtrip(bar->display);

	struct swaybar_seat *seat;
	wl_list_for_each(seat, &bar->seats, link) {
		struct swaybar_pointer *pointer = &seat->pointer;
		if (!pointer) {
			continue;
		}
		pointer->cursor_surface =
			wl_compositor_create_surface(bar->compositor);
		assert(pointer->cursor_surface);
	}

	if (bar->config->status_command) {
		bar->status = status_line_init(bar->config->status_command);
		bar->status->bar = bar;
	}

#if HAVE_TRAY
	if (!bar->config->tray_hidden) {
		bar->tray = create_tray(bar);
	}
#endif

	if (bar->config->workspace_buttons) {
		ipc_get_workspaces(bar);
	}
	determine_bar_visibility(bar, false);
	return true;
}

static void display_in(int fd, short mask, void *data) {
	struct swaybar *bar = data;
	if (mask & (POLLHUP | POLLERR)) {
		if (mask & POLLERR) {
			sway_log(SWAY_ERROR, "Wayland display poll error");
		}
		bar->running = false;
		return;
	}
	if (wl_display_dispatch(bar->display) == -1) {
		sway_log(SWAY_ERROR, "wl_display_dispatch failed");
		bar->running = false;
	}
}

static void ipc_in(int fd, short mask, void *data) {
	struct swaybar *bar = data;
	if (mask & (POLLHUP | POLLERR)) {
		if (mask & POLLERR) {
			sway_log(SWAY_ERROR, "IPC poll error");
		}
		bar->running = false;
		return;
	}
	if (handle_ipc_readable(bar)) {
		set_bar_dirty(bar);
	}
}

void status_in(int fd, short mask, void *data) {
	struct swaybar *bar = data;
	if (mask & (POLLHUP | POLLERR)) {
		status_error(bar->status, "[error reading from status command]");
		set_bar_dirty(bar);
		loop_remove_fd(bar->eventloop, fd);
	} else if (status_handle_readable(bar->status)) {
		set_bar_dirty(bar);
	}
}

void bar_run(struct swaybar *bar) {
	loop_add_fd(bar->eventloop, wl_display_get_fd(bar->display), POLLIN,
			display_in, bar);
	loop_add_fd(bar->eventloop, bar->ipc_event_socketfd, POLLIN, ipc_in, bar);
	if (bar->status) {
		loop_add_fd(bar->eventloop, bar->status->read_fd, POLLIN,
				status_in, bar);
	}
#if HAVE_TRAY
	if (bar->tray) {
		loop_add_fd(bar->eventloop, bar->tray->fd, POLLIN, tray_in, bar->tray->bus);
	}
#endif
	while (bar->running) {
		errno = 0;
		if (wl_display_flush(bar->display) == -1 && errno != EAGAIN) {
			break;
		}
		loop_poll(bar->eventloop);
	}
}

static void free_outputs(struct wl_list *list) {
	struct swaybar_output *output, *tmp;
	wl_list_for_each_safe(output, tmp, list, link) {
		swaybar_output_free(output);
	}
}

static void free_seats(struct wl_list *list) {
	struct swaybar_seat *seat, *tmp;
	wl_list_for_each_safe(seat, tmp, list, link) {
		swaybar_seat_free(seat);
	}
}

void bar_teardown(struct swaybar *bar) {
#if HAVE_TRAY
	destroy_tray(bar->tray);
#endif
	free_outputs(&bar->outputs);
	free_outputs(&bar->unused_outputs);
	free_seats(&bar->seats);
	if (bar->config) {
		free_config(bar->config);
	}
	close(bar->ipc_event_socketfd);
	close(bar->ipc_socketfd);
	if (bar->status) {
		status_line_free(bar->status);
	}
	free(bar->id);
	free(bar->mode);
}
