#include<stdio.h>
#include<stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
int searchVirus(char* virus, char* fileName);
int main(int argc, char** argv){
	DIR *dp;
	char directory[100];
	struct dirent *ep;
	int check;
	FILE * resultFile;
	char result1[] = "  not infected";
	char result2[] = "  INFECTED!";
	resultFile = fopen("AntiVirusLog.txt", "wb");
	printf("please write the name of the directory you want to search the files in\n");
	scanf("%s", directory);
	dp = opendir(directory);
	if (dp != NULL)
	{
		while (ep = readdir(dp))
		{
			check=searchVirus(argv[1],ep->d_name);
			printf("%d", check);
			if (check == 1)
			{
				int ret_code = fwrite(strcat(ep->d_name, result2), sizeof(char), strlen(result2), resultFile);
				if (ret_code != strlen(result2))
				{
					printf("there was a problem");
				}
			}
			if (check == 2)
			{
				int ret_code = fwrite(strcat(ep->d_name, result1), sizeof(char), strlen(result2), resultFile);
				if (ret_code != strlen(result2))
				{
					printf("there was a problem");
				}
			}
		}

		(void)closedir(dp);
	}
	else
	{
		perror("Couldn't open the directory");
	}
	fclose(resultFile);
	system("PAUSE");
	return (0);
}

int searchVirus(char* virus, char* fileName)/*if returns 0 something was wrong, if returns 1 the file
											is with a virus if returns 2 the file is okay*/
{
	FILE * virusFile;
	FILE * checkFile;
	int ch;
	char firstByte[1];//the first byte of the virus
	int length = 0;//what is the length of the virus
	int i;
	virusFile = fopen(virus, "rb");
	if (virusFile == NULL)
	{
		printf("Error opening first file");
		return 0;
	}
	checkFile = fopen(fileName, "rb");
	if (virusFile == NULL)
	{
		fclose(virusFile);
		printf("Error opening second file");
		return 0;
	}
	while ((ch = fgetc(virusFile)) != EOF)
	{
		length++;
	}
	char* strCheck = (char*)malloc(sizeof(char)*(length + 1));
	char* virusBinary = (char*)malloc(sizeof(char)*(length + 1));
	size_t ret_code1 = fread(virusBinary, sizeof (char), length, virusFile);
	printf("%d", ret_code1);
	if (ret_code1 == length)
	{
		size_t ret_code2 = fread(firstByte, 1, 1, virusFile);
		if (ret_code2 == 1)
		{
			while ((ch = fgetc(checkFile)) != EOF)
			{
				if (ch == firstByte)
				{
					i = 0;
					while (i < length && ch != firstByte)
					{
						strCheck[i] = ch;
						ch = fgetc(checkFile);
						i++;
					}
				}
				if (strcmp(strCheck, virusBinary) == 0)
				{
					return 1;
				}
				fseek(checkFile, (-1), SEEK_CUR);
			}
			return 2;
		}
		else
		{
			return 0;
		}
	}
	else
	{
		return 3;
	}
	free(strCheck);
	free(virusBinary);
	fclose(virusFile);
	fclose(checkFile);
}