/** @file shell.c */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include "log.h"
#include <sys/time.h>
#include "signal.h"

log_t *Log;
extern char ** environ;
char * str;
int am;
pid_t id2;
void ignoreExit(int signal)
{
	(void)signal;
	return;
}

void cleanZombie(int signal)
{
	(void)signal;
	int status;
  	while (waitpid((pid_t)(-1), &status, WNOHANG) > 0) {}
}

void printHistory()
{
	int i = 0;
	while(i < Log -> counter)
	{
		printf("%s\n", (Log -> data)[i]);
		i++;
	}
}

void forkStuff(int ti, char * st)
{
	int arg = 0;
	int counter = 0;
	while(1)
	{
		if(st[counter] == ' ')
			arg++;
		else if(st[counter] == '\0')
		{
			arg++;
			break;
		}
		counter++;
	}
	char ** argv = (char **) malloc((arg + 1)*sizeof(char*));
	char * delim = " ";
	char * first = strtok(st, delim);
	argv[0] = strdup(first);
	char * ptr;
	int g = 1;
	while ((ptr = strtok(NULL, delim)) != NULL) {
        	argv[g] = strdup(ptr);
        	g++;
    	}
    	argv[arg] = NULL;
	struct timeval start;
  	struct timeval end;
	if(ti == 1)
 		gettimeofday(&start, 0);
 	id2 = fork();
  	if(id2 == -1)
 		exit(EXIT_FAILURE);
 	else if(id2 == 0)
	{
		execvp(argv[0], argv);
        printf("%s: Command not found\n", argv[0]);
        int k = 0;
        while(k <= arg)
 		{
 			free(argv[k]);
 			k++;
 		}
 		free(argv);
 		log_destroy(Log);
 		free(st);
 		exit(0);
	}
 	else
 	{
 		if(am == 0)
		{
			printf("Command executed by pid = %d\n", id2);
			int status;
 			waitpid(id2, &status, 0);
 		}
 		else if(am == 1)
 		{
 			printf("Command executed by pid = %d\n", id2);
 			signal(SIGCHLD, cleanZombie);
 		}
 	}
 	if(ti == 1)
 	{
 		gettimeofday(&end, 0);
		long el = (end.tv_sec-start.tv_sec)*1000000 + end.tv_usec-start.tv_usec;
		printf("Execution took %ld microseconds.\n", el) ;
 	}
 	int k = 0;
 	while(k <= arg)
 	{
 		free(argv[k]);
 		k++;
 	}
 	free(argv);

}

void changeDirectory(char * s)
{
	char * dir = (char *)malloc((strlen(s) - 1)*sizeof(char)) ;
 	strcpy(dir, s + 3);
 	int sd = chdir(dir);
 	if(sd == -1)
 		printf("%s: No such file or directory\n", dir);
 	free(dir);
}
/**
 *  * Starting point for shell.
 *   */
int main(int argc, char ** argv) {
    /**
 *       * Analyze command line arguments
 *             */
	Log = malloc(sizeof(log_t));
	log_init(Log);
 	int tz = 0;
	if(argc > 1)
	{
 		if(strcmp(argv[1], "-h") == 0)
			printf("Shell by vinhha2\n");
		else if(strcmp(argv[1], "=") == 0)
		{
			char ** ptr = environ;
			while(*ptr)
			{
				printf("%s\n", *ptr);
				ptr++;
			}
		}
		else if(strcmp(argv[1], "-f") == 0)
		{
			FILE* f = fopen(argv[2], "r");
			if(f != NULL)
			{
				char* str1 = NULL;
				size_t size1 = 0;
				while(!feof(f)){
        				getline(&str1, &size1, f);
        				system(str1);
      				}
      			free(str1);
 			}
 			fclose(f);
		}
		else if(strcmp(argv[1], "-t") == 0)
			tz = 1;
	}
    	signal(SIGINT, ignoreExit);
	while(1)
    {
	/**
 * 	 * Print a command prompt
 * 	 	 */
		am = 0;
		int id = getpid();
		char wd[1024];
		getcwd(wd, sizeof(wd));
		printf("(pid=%d)%s$ ", id, wd);
	/**
 * 	 * Read the commands
 * 	 	 */
		str = NULL;
		size_t size = 0;
		getline(&str, &size, stdin);
		if(strcmp(str, "\n") == 0)
		{
			free(str);
			continue;
		}
		signal(SIGINT, ignoreExit);
		char * lol = strndup(str, strlen(str) - 1);
		free(str);
		str = strdup(lol);
		free(lol);
		if(strstr(str, "!") == NULL)
			log_push(Log, str);
	/**
 * 	 * Print the PID of the process executing the command
 * 	 	 */

	/**
 * 	 * Decide which actions to take based on the command (exit, run program, etc.)
 * 	 	 */
 		if(strstr(str, "cd ") != NULL && str[0] == 'c')
 		{
 			changeDirectory(str);
 		}
 		else if(strcmp(str, "exit") == 0)
 		{
 			log_destroy(Log);
 			free(str);
 			exit(0);
 		}
 		else if(strcmp(str, "!#") == 0)
 		{
 			printHistory();
 		}
		else if(str[0] == '!')
		{
			if(strlen(str) == 1)
			{
				free(str);
				printf("No Match\n");
				continue;
			}
			char * abc = str + 1;
			char * s = strdup(abc);
			char * argg = log_search(Log, s);
			if(argg == NULL)
			{
				printf("No Match\n");
				free(s);
				free(str);
				continue;
			}
			else
			{
				printf("%s matches %s\n", s, argg);
				free(str);
				str = strdup(argg);
				free(argg);
				free(s);

				if(strstr(str, "cd ") != NULL)
				{
					changeDirectory(str);
				}
				else if(strstr(str, "&") != NULL)
				{
					char * ok;
					if(strstr(str, " &") != NULL)
						ok = strndup(str, strlen(str) - 2);
					else
						ok = strndup(str, strlen(str) - 1);
					free(str);
					str = strdup(ok);
					free(ok);
					am = 1;
					forkStuff(tz, str);
				}
				else
				{
					forkStuff(tz, str);
				}
			}
		}
		else if(strstr(str, "&") != NULL)
		{
			char * ok;
			int k = 1;
			int abcd = 0;
			int le = strlen(str);
			while(abcd < le - 1)
			{
				if(str[abcd] == ' ')
					k++;
				else
					k = 1;
				lol++;
				abcd++;
			}
			ok = strndup(str, strlen(str) - k);
			free(str);
			str = strdup(ok);
			free(ok);
			am = 1;
			forkStuff(tz, str);
		}
 		else
 		{
 			forkStuff(tz, str);
 		}
 		free(str);
    }
    return 0;
}