/**
 * trans - A program to replace characters in stdin
 * a replication of tr(1)
 * by Nathaniel "Nat" Welch
 * CSC 357
 * Due 4/9/08
 *
 * DF 82 8A F5 6F EF 0F 15 F6 12 09 0B 03 21 DA CF
 */

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

/*Function Stubs */
int parseArgs(char* arg);
int parseLine(char* ret);
void print(char* arg);
void replace(char* in, char* set1, char* set2);
int delete(char* set1, char* in);

int main(int argc, char * argv[])
{
	char* work = NULL;

	work = (char*)malloc(sizeof(char)*100);
	
	if(argc == 1 || argc > 3)
	{
		printf("Trans, a simple implementation of tr\n");
		printf("use: %s [-d] SET1 [SET2]\n",argv[0]);
		return 1;
	}
	else
	{
		while(!parseLine(work))
		{
			/*
			print(work);
			*/
			if(strcmp("-d", argv[1]) == 0)	
			{
				delete(argv[2],work);
				print(work);
			}
			else if(argc == 3)
			{
				replace(work,argv[1],argv[2]);
				print(work);
			}
			else
			{
				printf("I'm Sorry, your variables are incorrect.\n");
				return 2;
			}
		}
		
		free(work);
		return 0;
	}
}

/** 
 * Replaces characters from set1 with those of set2 in in.
 */
void replace(char* in, char* set1, char* set2)
{
	int c = 0;
	int r = 0;

	while(*(in + c) != '\0')
	{
		r = 0;
		while(*(set1 + r) != '\0')
		{
			if(*(in + c) == *(set1 + r))
			{
				*(in + c) = *(set2 + r);
			}
			r++;
		}
		c++;
	}
}

/**
 * prints out the provided char array.
 */
void print(char* arg)
{
	int c = 0;
	while(*(arg + c) != '\0')
	{
		printf("%c",*(arg + c));
		c++;
	}
	printf("\n");
}

/**
 * deletes the chars in set1 from in
 */
int delete(char* set1, char* in)
{
	int c = 0;
	int r = 0;

	while(*(in + c) != '\0')
	{
		while(*(set1 + r) != '\0')
		{
			if(*(in + c) == *(set1 + r))
			{
				/*delete crap...*/
			}
			r++;
		}
		c++;
	}
	return 0;
}

/* parses input. return 1 if last char is EOF */
int parseLine(char* ret)
{
	char temp;
	int c = 0;
	int edge = 100;
	int die = 0;

	/*
	ret = (char*)malloc(sizeof(char)*edge);
*/
	temp = (char)getchar();
	while(temp != '\n')
	{
		*(ret + c) = temp;
		c++;
		temp = (char)getchar();
		if( c == edge-1)
		{
			edge += 100;
			ret = (char*)realloc(ret, sizeof(char)*edge);
		}
		if(temp == EOF)
		{
			die = 1;
		}
	}

	*(ret + c) = '\0';

	return die;
}

/* Replaces special chars in arguments */
int parseArgs(char* arg)
{
	int c = 0;
	int d = 0;
	int ret = 0;

	while(*(arg + c) != '\0')
	{
		if(*(arg + c) == '\\')
		{
			if(*(arg + c + 1) == 'n')
			{
				*(arg + c) = '\n';
				ret++;
			}
			else if(*(arg + c + 1) == 't')
			{
				*(arg + c) = '\t';
				ret++;
			}
			else if(*(arg + c + 1) == '\\')
			{
				*(arg + c) = '\\';
				ret++;
			}
			d = c;
			while(*(arg + d) != '\0')
			{
				*(arg + d) = *(arg + d + 1);
				d++;
			}
		}
		else
		{
			c++;
		}
	}
	return ret;
}