/**
 * Copyright (c) 2025 favewa
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include "ratazana.h"

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

#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>

#include <linux/hidraw.h>
#include <sys/ioctl.h>

static constexpr int HID_OPEN_FLAGS = O_RDONLY | O_NONBLOCK;

static ratazana_result_t query_hidraw_info(int fd, const char *path,
										   ratazana_hid_device_t *info)
{
	struct hidraw_devinfo devinfo = {0};
	if (ioctl(fd, HIDIOCGRAWINFO, &devinfo) < 0)
		return close(fd), RATAZANA_ERROR_IO;

	char name[256] = {0};
	if (ioctl(fd, HIDIOCGRAWNAME(sizeof(name)), name) < 0)
		strncpy(name, "Unknown Device", sizeof(name) - 1);

	*info = (ratazana_hid_device_t){
		.vendor_id = devinfo.vendor,
		.product_id = devinfo.product,
		.bus_type = devinfo.bustype,
	};
	strncpy(info->path, path, sizeof(info->path) - 1);
	strncpy(info->name, name, sizeof(info->name) - 1);

	return close(fd), RATAZANA_OK;
}

ratazana_result_t ratazana_hid_enumerate(ratazana_hid_device_t *out,
										 ratazana_device_matcher_t match)
{
	if (!out)
		return RATAZANA_ERROR_INVALID_ARG;

	DIR *dir = opendir("/dev");
	if (dir == nullptr)
		return RATAZANA_ERROR_IO;

	struct dirent *entry;
	ratazana_result_t result = RATAZANA_ERROR_NOT_FOUND;

	while ((entry = readdir(dir)) != nullptr) {
		if (strncmp(entry->d_name, "hidraw", 6) != 0)
			continue;

		char path[256];
		snprintf(path, sizeof(path), "/dev/%s", entry->d_name);

		int fd = open(path, HID_OPEN_FLAGS);
		if (fd < 0)
			continue;

		ratazana_hid_device_t info = {0};
		ratazana_result_t query_result = query_hidraw_info(fd, path, &info);

		close(fd);
		if (query_result)
			continue;

		if (match == nullptr || match(&info))
			return (*out = info), closedir(dir), RATAZANA_OK;
	}

	return closedir(dir), result;
}

ratazana_result_t ratazana_device_open(ratazana_device_t *restrict dev,
									   const char *restrict path,
									   uint8_t device_index)
{
	if (!dev || !path)
		return RATAZANA_ERROR_INVALID_ARG;

	dev->fd = open(path, O_RDWR);
	if (dev->fd < 0) {
		perror("Failed to open device");
		if (errno == EACCES) {
			fprintf(stderr, "Hint: You may need root privileges or udev rules "
							"to access this device\n");
			return RATAZANA_ERROR_ACCESS;
		}
		return RATAZANA_ERROR_IO;
	}

	strncpy(dev->path, path, sizeof(dev->path) - 1);
	dev->idx = device_index;

	printf("Device opened: %s [idx=0x%02X]\n", path, device_index);
	return RATAZANA_OK;
}

void ratazana_device_close(ratazana_device_t *dev)
{
	if (dev != nullptr && dev->fd >= 0) {
		close(dev->fd);
		dev->fd = -1;
	}
}