#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "y.tab.h"

int main()
{
	printf("/////////////////////////////\n");
	printf("///\tThe Nutshell\n");
	printf("///\t-Joseph Szigeti\n///\t-Dimitar Dinev\n");
	printf("///\tDefault PATH=/bin/\n");
	printf("///\tOur Pipe command only works with single words\n");
	printf("///\t e.g. cmd1 | cmd2\n");
	printf("///\tPipe seems to crash the shell after running\n");
	putenv("PATH=/bin/");
	putenv("PRMPT=shell");
	int i = 0;
	while(1)
	{
		char * prompt;
		prompt = getenv("PRMPT");
		printf("%s %d: ",prompt,i++);
		yyparse();
	}
}

void pip(char * arg1, char * arg2)
{
	printf("\targ1: %s\n",arg1);
	printf("\targ2: %s\n",arg2);
	printf("\t%s | %s\n",arg1,arg2);

	int pipefd[2];

  	char *cmd1[] = {arg1, NULL};
  	char *cmd2[] = {arg2, NULL};

 	pipe(pipefd);

  	if (fork() == 0)
    	{
      		dup2(pipefd[0], 0);
      		close(pipefd[1]);
      		execvp(cmd2[0], cmd2);
    	}
  	else
    	{
      		dup2(pipefd[1], 1);
      		close(pipefd[0]);
      		execvp(cmd1[0], cmd1);
    	}
}

void bye()
{
	printf("\tbye'd\n");
	exit(1);
}

void set()
{
	printf("\tPath: %s\n",getenv("PATH"));
	printf("\tPrompt: %s\n",getenv("PRMPT"));
}

void setp(char *prm)
{
	char *var = "PRMPT=";
	char *val = prm;
	char *str3;
	str3 = (char *)calloc(strlen(var)+strlen(val)+1,sizeof(char));
	strcat(str3,var);
	strcat(str3,val);
	printf("\t%s\n",str3);
	putenv(str3);
}

void setpa(char *pat)
{
	char *var = "PATH=";
	char *val = pat;
	char *str3;
	str3 = (char *)calloc(strlen(var)+strlen(val)+1,sizeof(char));
	strcat(str3,var);
	strcat(str3,val);
	printf("\t%s\n",str3);
	putenv(str3);
}

void cd()
{
	chdir("/home");
}

void cdd(char *dir)
{
	int error = chdir(dir);
	if (error != 0) {printf("Error, directory unchanged");}
}

void run(char *com)
{
	char *var = "PATH=";
	char *val = com;
	char *str3;
	str3 = (char *)calloc(strlen(var)+strlen(val)+1,sizeof(char));
	strcat(str3,var);
	strcat(str3,val);
	printf("\t%s\n",str3);
	system(str3);
}

void aliasList()
{
	char name[10];
	char command[100];
        FILE *fp;
	if (fp = fopen("alias","r"))
	{
        	while (fscanf(fp,"%s %s",name,command) != EOF)
			printf("%s = %s\n",name,command);

		fclose(fp);
	}
	else
		printf("Error: alias file does not exist");
}

void alias(char *name, char *command)
{
	FILE *ofp;
        ofp = fopen("alias","a");
	fprintf(ofp,"%s %s",name,command);
        fclose(ofp);
}

void unalias(char *search)
{
	char name[10];
	char command[100];
	FILE *ifp, *ofp;
	ofp = fopen("temp","w");
	if (ifp = fopen("alias","r"))
	{
		while (fscanf(ifp,"%s %s",name,command) != EOF)
			if (strcmp(name,search)!=0)
				fprintf(ofp,"%s %s\n",name,command);

		fclose(ifp);
		fclose(ofp);
		unlink("alias");
		rename("temp","alias");
	}
	else
		printf("Error: alias file does not exist");
}

int aliasCheck(char *search)
{
	int bool;
	char name[10];
	char command[100];
	FILE *ifp;

	if(ifp = fopen("alias","r"))
	{
		while (fscanf(ifp,"%s %s",name,command) != EOF)
			if (strcmp(name,search)!=0)
				bool=0;
			else
				return 1;

		fclose(ifp);
		return bool;
	}
	return 0;
}

void aliasExec(char *search)
{
	char name[10];
	char command[100];
	FILE *ifp;

	if(ifp = fopen("alias","r"))
	{
		while (fscanf(ifp,"%s %s",name,command) != EOF)
			if (strcmp(name,search)==0)
				system(command);

		fclose(ifp);
	}
}

void aliasHelper(char * str)
{
	*str++;
	str[strlen(str)-1] = NULL;
	printf("\t%s\n",str);
	system(str);
}