#include <paths.h>
#include <sys/stat.h>
#include <stdio.h>
#include <cerrno>
#include <cstring>
#include <string>
#include "../os.h"
#include "../../base/logger.h"

#include <mntent.h>
#include <dirent.h>
#include <sys/utsname.h>
#ifndef NDEBUG
#include <valgrind/memcheck.h>
#endif

#ifdef USE_DBUS
#include <dbus-1.0/dbus/dbus.h>
#endif

/**
 *Usually uuid are hex number separated by "-". this method read up to 8 hex
 *numbers skipping - characters.
 *@param uuid uuid as read in /dev/disk/by-uuid
 *@param buffer_out: unsigned char buffer[8] output buffer for result
 */
static void parseUUID(const char *uuid, unsigned char *buffer_out, unsigned int out_size) {
	unsigned int i, j;
	char *hexuuid;
	unsigned char cur_character;
	// remove characters not in hex set
	size_t len = strlen(uuid);
	hexuuid = (char *)malloc(sizeof(char) * len);
	memset(buffer_out, 0, out_size);
	memset(hexuuid, 0, sizeof(char) * len);

	for (i = 0, j = 0; i < len; i++) {
		if (isxdigit(uuid[i])) {
			hexuuid[j] = uuid[i];
			j++;
		} else {
			// skip
			continue;
		}
	}
	if (j % 2 == 1) {
		hexuuid[j++] = '0';
	}
	hexuuid[j] = '\0';
	for (i = 0; i < j / 2; i++) {
		sscanf(&hexuuid[i * 2], "%2hhx", &cur_character);
		buffer_out[i % out_size] = buffer_out[i % out_size] ^ cur_character;
	}

	free(hexuuid);
}

#define MAX_UNITS 40
FUNCTION_RETURN getDiskInfos(DiskInfo *diskInfos, size_t *disk_info_size) {
	struct stat mount_stat, sym_stat;
	/*static char discard[1024];
	 char device[64], name[64], type[64];
	 */
	char cur_dir[MAX_PATH];
	struct mntent *ent;

	int maxDrives, currentDrive, i, drive_found;
	__ino64_t *statDrives = NULL;
	DiskInfo *tmpDrives = NULL;
	FILE *aFile = NULL;
	DIR *disk_by_uuid_dir = NULL, *disk_by_label = NULL;
	struct dirent *dir = NULL;
	FUNCTION_RETURN result;

	if (diskInfos != NULL) {
		maxDrives = *disk_info_size;
		tmpDrives = diskInfos;
	} else {
		maxDrives = MAX_UNITS;
		tmpDrives = (DiskInfo *)malloc(sizeof(DiskInfo) * maxDrives);
	}
	memset(tmpDrives, 0, sizeof(DiskInfo) * maxDrives);
	statDrives = (__ino64_t *)malloc(maxDrives * sizeof(__ino64_t));
	memset(statDrives, 0, sizeof(__ino64_t) * maxDrives);

	aFile = setmntent("/proc/mounts", "r");
	if (aFile == NULL) {
		/*proc not mounted*/
		free(tmpDrives);
		free(statDrives);
		return FUNC_RET_ERROR;
	}

	currentDrive = 0;
	while (NULL != (ent = getmntent(aFile)) && currentDrive < maxDrives) {
		if ((strncmp(ent->mnt_type, "ext", 3) == 0 || strncmp(ent->mnt_type, "xfs", 3) == 0 ||
			 strncmp(ent->mnt_type, "vfat", 4) == 0 || strncmp(ent->mnt_type, "ntfs", 4) == 0 ||
			 strncmp(ent->mnt_type, "btr", 3) == 0) &&
			ent->mnt_fsname != NULL && strncmp(ent->mnt_fsname, "/dev/", 5) == 0) {
			if (stat(ent->mnt_fsname, &mount_stat) == 0) {
				drive_found = -1;
				for (i = 0; i < currentDrive; i++) {
					if (statDrives[i] == mount_stat.st_ino) {
						drive_found = i;
					}
				}
				if (drive_found == -1) {
					LOG_DEBUG("mntent fs:[%s],dir:[%s],inode:[%d]\n", ent->mnt_fsname, ent->mnt_dir,
							  (unsigned long int)mount_stat.st_ino);
					strncpy(tmpDrives[currentDrive].device, ent->mnt_fsname, 255 - 1);
					statDrives[currentDrive] = mount_stat.st_ino;
					drive_found = currentDrive;
					currentDrive++;
				}
				if (strcmp(ent->mnt_dir, "/") == 0) {
					strcpy(tmpDrives[drive_found].label, "root");
					LOG_DEBUG("drive %s set to preferred\n", ent->mnt_fsname);
					tmpDrives[drive_found].preferred = 1;
				} else {
					tmpDrives[drive_found].preferred = 0;
				}
			} else {
				LOG_DEBUG("Error %s during stat of %s \n", std::strerror(errno), ent->mnt_fsname);
			}
		}
	}
	endmntent(aFile);

	if (diskInfos == NULL) {
		*disk_info_size = currentDrive;
		free(tmpDrives);
		result = (currentDrive > 0) ? FUNC_RET_OK : FUNC_RET_NOT_AVAIL;
	} else if (*disk_info_size >= currentDrive) {
		disk_by_uuid_dir = opendir("/dev/disk/by-uuid");
		if (disk_by_uuid_dir == nullptr) {
			LOG_WARN("Open /dev/disk/by-uuid fail");
			free(statDrives);
			return FUNC_RET_ERROR;
		}
		result = FUNC_RET_OK;
		*disk_info_size = currentDrive;

		while ((dir = readdir(disk_by_uuid_dir)) != nullptr) {
			std::string cur_dir("/dev/disk/by-uuid/");
			cur_dir += dir->d_name;

			bool found = false;
			if (stat(cur_dir.c_str(), &sym_stat) == 0) {
				for (i = 0; i < currentDrive; i++) {
					if (sym_stat.st_ino == statDrives[i]) {
						found = true;
						parseUUID(dir->d_name, tmpDrives[i].disk_sn, sizeof(tmpDrives[i].disk_sn));
#ifndef NDEBUG
						VALGRIND_CHECK_VALUE_IS_DEFINED(tmpDrives[i].device);
						LOG_DEBUG("uuid %d %s %02x%02x%02x%02x", i, tmpDrives[i].device, tmpDrives[i].disk_sn[0],
								  tmpDrives[i].disk_sn[1], tmpDrives[i].disk_sn[2], tmpDrives[i].disk_sn[3]);
#endif
					}
				}
				if (!found) {
					LOG_DEBUG("Drive [%s], num [%d] inode [%d] did not match any existing drive", cur_dir.c_str(),
							  (unsigned long int)sym_stat.st_ino);
				}
			} else {
				LOG_DEBUG("Error %s during stat of %s", std::strerror(errno), cur_dir.c_str());
			}
		}
		closedir(disk_by_uuid_dir);

		disk_by_label = opendir("/dev/disk/by-label");
		if (disk_by_label != nullptr) {
			while ((dir = readdir(disk_by_label)) != nullptr) {
				strcpy(cur_dir, "/dev/disk/by-label/");
				strcat(cur_dir, dir->d_name);
				if (stat(cur_dir, &sym_stat) == 0) {
					for (i = 0; i < currentDrive; i++) {
						if (sym_stat.st_ino == statDrives[i]) {
							strncpy(tmpDrives[i].label, dir->d_name, 255 - 1);
							LOG_DEBUG("label %d %s %s", i, tmpDrives[i].label, tmpDrives[i].device);
						}
					}
				}
			}
			closedir(disk_by_label);
		}
	} else {
		result = FUNC_RET_BUFFER_TOO_SMALL;
	}
	free(statDrives);
	return result;
}

FUNCTION_RETURN getMachineName(unsigned char identifier[6]) {
	static struct utsname u;

	if (uname(&u) < 0) {
		return FUNC_RET_ERROR;
	}
	memcpy(identifier, u.nodename, 6);
	return FUNC_RET_OK;
}

FUNCTION_RETURN getOsSpecificIdentifier(unsigned char identifier[6]) {
#if USE_DBUS
	char *dbus_id = dbus_get_local_machine_id();
	if (dbus_id == NULL) {
		return FUNC_RET_ERROR;
	}
	memcpy(identifier, dbus_id, 6);
	dbus_free(dbus_id);
	return FUNC_RET_OK;
#else
	return FUNC_RET_NOT_AVAIL;
#endif
}

FUNCTION_RETURN getModuleName(char buffer[MAX_PATH]) {
	FUNCTION_RETURN result;
	char path[MAX_PATH] = {0};
	char proc_path[MAX_PATH], pidStr[64];
	pid_t pid = getpid();
	sprintf(pidStr, "%d", pid);
	strcpy(proc_path, "/proc/");
	strcat(proc_path, pidStr);
	strcat(proc_path, "/exe");

	int ch = readlink(proc_path, path, MAX_PATH - 1);
	if (ch != -1) {
		path[ch] = '\0';
		strncpy(buffer, path, ch);
		result = FUNC_RET_OK;
	} else {
		result = FUNC_RET_ERROR;
	}
	return result;
}