// This is for asprintf support.
// TODO: Don't use asprintf and remove this.
#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libusb-1.0/libusb.h>

#include "accel_monitor.h"
#include "device_information.h"
#include "output_manager.h"
#include "usb_device_detection.h"

static struct device_information get_device_info_for_name(
    char const* const device_name)
{
	if (strcmp(device_name, "generic") == 0) {
		fprintf(
		    stderr,
		    "WARNING: Using a 'generic' device. This may not work properly.\n");
		return DEVICE_INFORMATION_GENERIC;
	}

	static size_t const device_info_count =
	    sizeof(DEVICE_INFOS) / sizeof(*DEVICE_INFOS);
	for (size_t i = 0; i < device_info_count; ++i) {
		struct device_information current = DEVICE_INFOS[i];
		if (strcmp(current.device_name, device_name) == 0) return current;
	}

	fprintf(stderr,
	        "No matching configuration for '%s'. Using the generic "
	        "configuration.\n",
	        device_name);

	return DEVICE_INFORMATION_GENERIC;
}

static char* get_hook_path(char const* const hook_name)
{
	char* path;
	char* xdg_config_dir = getenv("XDG_CONFIG_HOME");
	if (xdg_config_dir)
		asprintf(
		    &path, "%s/convertablet/hooks/%s-hook", xdg_config_dir, hook_name);
	else
		asprintf(&path,
		         "%s/.config/convertablet/hooks/%s-hook",
		         getenv("HOME"),
		         hook_name);
	return path;
}

static void on_basestation_connected()
{
	printf("Basestation connected\n");

	char* hook_path = get_hook_path("basestation-connected");

	if (access(hook_path, X_OK) != 0) {
		fprintf(stderr, "Couldn't read or execute hook at %s\n", hook_path);
		free(hook_path);
		return;
	}

	pid_t pid = fork();

	if (pid < 0) {
		// Error
		fprintf(stderr, "Unable to run hook script!\n");
		perror("fork");
	} else if (pid == 0) {
		// In the child
		char* argv[] = {hook_path, 0};
		execve(hook_path, argv, environ);
		exit(-1);
	} else {
		free(hook_path);
	}
}

static void on_basestation_disconnected()
{
	printf("Basestation disconnected\n");

	char* hook_path = get_hook_path("basestation-disconnected");

	if (access(hook_path, X_OK) != 0) {
		// Hook is innaccessible
		fprintf(stderr, "Couldn't read or execute hook at %s\n", hook_path);
		free(hook_path);
		return;
	}

	pid_t pid = fork();

	if (pid < 0) {
		// Error
		fprintf(stderr, "Unable to run hook script!\n");
		perror("fork");
	} else if (pid == 0) {
		// In the child
		char* argv[] = {hook_path, 0};
		execve(hook_path, argv, environ);
		exit(-1);
	} else {
		free(hook_path);
	}
}

static enum accel_rotation last_accel_rotation = ACCEL_ROTATION_NO_CHANGE;

int main(int argc, char** argv)
{
	if (argc < 2) {
		fprintf(stderr,
		        "No device specified! Please specify your device's name or use "
		        "'generic' for sane defaults.\n");
		fprintf(stderr, "\tUsage: %s <device name>\n", argv[0]);
		fprintf(stderr, "\t       %s list-devices \n", argv[0]);
		return -1;
	}

	if (strcmp(argv[1], "list-devices") == 0) {
		printf("Device names:\n");
		static size_t const device_info_count =
		    sizeof(DEVICE_INFOS) / sizeof(*DEVICE_INFOS);
		for (size_t i = 0; i < device_info_count; ++i)
			printf("\t- %s\n", DEVICE_INFOS[i].device_name);
		return 0;
	}

	struct device_information device_info = get_device_info_for_name(argv[1]);

	struct accel_monitor*          monitor = 0;
	struct convertablet_wlr_state* state   = 0;
	if (device_info.screen_rotation_supported) {
		monitor = accel_start_monitor(device_info.target_motion_sensor);
		if (!monitor) {
			fprintf(stderr, "Failed to start iio motion monitoring\n");
			return -1;
		}

		state = convertablet_wlr_init();
		if (!state) {
			fprintf(stderr, "Failed to connect to wayland server.\n");
			return -1;
		}
	} else
		fprintf(stderr, "Screen rotation not supported.\n");

	struct usb_detector* base_station_detector = 0;
	if (device_info.basestation_detection_supported) {
		base_station_detector =
		    create_detector(device_info.basestation_vendor_id,
		                    device_info.basestation_product_id);
		if (!base_station_detector) {
			fprintf(stderr, "Failed to create basestation detector.\n");
			return -1;
		}

		base_station_detector->on_connected    = &on_basestation_connected;
		base_station_detector->on_disconnected = &on_basestation_disconnected;
		base_station_detector->has_hotplug_callbacks = true;
	} else
		fprintf(stderr, "Base station detection not supported.\n");

	for (;;) { // Main loop that handles the rotation detection.
		// If screen rotation isn't supported, let's just do nothing.
		if (!device_info.screen_rotation_supported) continue;

		thrd_sleep(&(struct timespec){0, 10000000UL}, NULL);
		if (!monitor->data_is_ready) continue;

		if (base_station_detector && base_station_detector->is_connected) {
			if (last_accel_rotation != ACCEL_ROTATION_0DEG) {
				convertablet_wlr_head_set_transform(
				    state,
				    device_info.target_output,
				    device_info.sensor_to_output_rotation[ACCEL_ROTATION_0DEG]);
				last_accel_rotation = ACCEL_ROTATION_0DEG;
			}
			continue;
		}

		enum accel_rotation rotation = accel_get_current_rotation(monitor);
		if (rotation == ACCEL_ROTATION_NO_CHANGE ||
		    rotation == last_accel_rotation)
			continue;
		convertablet_wlr_head_set_transform(
		    state,
		    device_info.target_output,
		    device_info.sensor_to_output_rotation[rotation]);
		last_accel_rotation = rotation;
	}

	if (device_info.screen_rotation_supported) {
		accel_stop_monitor(monitor);
		convertablet_wlr_cleanup(state);
	}

	if (device_info.basestation_detection_supported)
		destroy_detector(base_station_detector);
}