#include "entry.h"

#include "utils.h"
#include "disk.h"

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/stat.h>

bool is_entry_id_valid(const char* entry_id) {
	if (entry_id == NULL)
		return false;

	size_t length = strlen(entry_id);

	// Check that the length is valid
	if (length == 0 || length > MAX_ENTRY_LENGTH)
		return false;

	// Check that the entry id does not contain any slashes
	for (size_t i = 0; i < length; i++)
		if (entry_id[i] == '/')
			return false;

	// Check that the entry id is not a reserved name
	if (strcmp(entry_id, ".") == 0 || strcmp(entry_id, "..") == 0)
		return false;

	return true;
}

Result get_entry_path(const char* entry_id, char** out_path) {
	*out_path = NULL;

	// Check that the entry id is valid
	if (!is_entry_id_valid(entry_id)) {
		log_message(LOG_LEVEL_ERROR, "Invalid entry id '%s'.", entry_id);
		return FAILURE;
	}

	return format(out_path, "%s/%s", ENTRY_POOL_DIR, entry_id);
}

Result entry_exists(const char* entry_id, bool* out_exists) {
	*out_exists = false;

	// Get the path of the entry
	char* path;
	Result result = get_entry_path(entry_id, &path);
	if (result != SUCCESS)
		return result;

	// Check if the entry exists and is a directory
	struct stat st;
	bool exists = stat(path, &st) == 0 && S_ISDIR(st.st_mode);

	// Free the path
	free(path);

	// Output the result
	*out_exists = exists;

	return SUCCESS;
}

Result add_root_entry(const char* entry_id, uint64_t size) {
	// Check that the entry does not exist
	bool exists;
	Result result = entry_exists(entry_id, &exists);
	if (result != SUCCESS)
		return result;

	if (exists) {
		log_message(LOG_LEVEL_ERROR, "Entry '%s' already exists.", entry_id);
		return FAILURE;
	}

	// Get the path of the entry
	char* path;
	result = get_entry_path(entry_id, &path);
	if (result != SUCCESS)
		return result;

	// Create the directory
	int return_code = mkdir(path, 0755);

	// Free the path as it is no longer needed
	free(path);

	// Check if the directory was created
	if (return_code != 0) {
		log_message(LOG_LEVEL_ERROR, "Failed to create the entry '%s' (%s).", entry_id, strerror(errno));
		return FAILURE;
	}

	// Get the disk path
	char* disk_path;
	result = get_entry_disk_path(entry_id, &disk_path);
	if (result != SUCCESS) {
		remove_entry(entry_id);
		return result;
	}

	// Create the disk
	result = create_root_disk(disk_path, size, 0644);

	// Free the disk path as it is no longer needed
	free(disk_path);

	// Remove the entry if the disk could not be created
	if (result != SUCCESS) {
		remove_entry(entry_id);
		return result;
	}

	return SUCCESS;
}

Result remove_entry(const char* entry_id) {
	// Remove the disk
	char* disk_path;
	Result result = get_entry_disk_path(entry_id, &disk_path);
	if (result == SUCCESS) {
		unlink(disk_path);
		free(disk_path);
	}

	// Get the path of the entry
	char* path;
	result = get_entry_path(entry_id, &path);
	if (result != SUCCESS)
		return result;

	// Remove the directory
	int return_code = rmdir(path);

	// Free the path as it is no longer needed
	free(path);

	// Check if the directory was removed
	if (return_code != 0) {
		log_message(LOG_LEVEL_ERROR, "Failed to remove the entry '%s' (%s).", entry_id, strerror(errno));
		return FAILURE;
	}

	return SUCCESS;
}

Result get_entry_disk_path(const char* entry_id, char** out_path) {
	*out_path = NULL;

	// Get the path of the entry
	char* path;
	Result result = get_entry_path(entry_id, &path);
	if (result != SUCCESS)
		return result;

	// Format the disk path
	result = format(out_path, "%s/disk", path);

	// Free the path as it is no longer needed
	free(path);

	return result;
}