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

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

#include <libusb-1.0/libusb.h>

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

static enum wl_output_transform const SENSOR_TO_OUTPUT_ROTATION[] = {
    [ACCEL_ROTATION_0DEG]   = WL_OUTPUT_TRANSFORM_270,
    [ACCEL_ROTATION_90DEG]  = WL_OUTPUT_TRANSFORM_NORMAL,
    [ACCEL_ROTATION_180DEG] = WL_OUTPUT_TRANSFORM_90,
    [ACCEL_ROTATION_270DEG] = WL_OUTPUT_TRANSFORM_180,
};

static char const* const DEFAULT_OUTPUT = "DSI-1";
static char const* const DEFAULT_MOTION_SENSOR =
    "/sys/bus/iio/devices/iio:device0";

static uint16_t const BASESTATION_VENDOR_ID  = 0x048d;
static uint16_t const BASESTATION_PRODUCT_ID = 0x8911;

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, char**)
{
	struct accel_monitor* monitor = accel_start_monitor(DEFAULT_MOTION_SENSOR);

	if (!monitor) {
		fprintf(stderr, "Failed to start iio motion monitoring\n");
		return -1;
	}

	struct usb_detector* base_station_detector =
	    create_detector(BASESTATION_VENDOR_ID, BASESTATION_PRODUCT_ID);

	base_station_detector->on_connected          = &on_basestation_connected;
	base_station_detector->on_disconnected       = &on_basestation_disconnected;
	base_station_detector->has_hotplug_callbacks = true;

	struct miix_wlr_state* state = miix_wlr_init();

	for (;;) {
		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) {
				miix_wlr_head_set_transform(
				    state,
				    DEFAULT_OUTPUT,
				    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;
		miix_wlr_head_set_transform(
		    state, DEFAULT_OUTPUT, SENSOR_TO_OUTPUT_ROTATION[rotation]);
		last_accel_rotation = rotation;
	}

	accel_stop_monitor(monitor);
	destroy_detector(base_station_detector);
	miix_wlr_cleanup(state);
}