#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <dirent.h>
#include <errno.h>
#include <pwd.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <fcntl.h>
#include <ctype.h>

const int max = 1000;

void cut(char **argv, char *command){
	int w = 0;
	char sep[] = " ";
	char *ptr = strtok(command, sep);
	while (ptr != NULL){
		argv[w]=ptr;
		w+=1;
		ptr = strtok(NULL, sep);
	}
	argv[w]=NULL;
}

void rmChar(char *str, char garbage) {   /*przesledzic jak to dziala!!!!! w opisie sobie napisac*/
    char *src, *dst;
    for (src = dst = str; *src != '\0'; src++) {
        *dst = *src;
        if (*dst != garbage) dst++;
    }
    *dst = '\0';
}

void cd (char **argv){
	if(argv[1] == NULL){
		printf("Add arguments\n");
		return;
	}
	else if(argv[2] != NULL){
		printf("Too many arguments\n");
		return;
	}
	else{
		if (chdir(argv[1]) != 0)
			perror("chdir error");
		return;
	}
}

void spathf (char **argv, int *spath){
	int l;
	if (argv[1] == NULL){
		printf("Add arguments\n");
		return;
	}
	else if (argv[2] != NULL){
		printf("Too many arguments\n");
		return;
	}
	else if (!strcmp(argv[1], "help")){
		printf("Arguments:\n0 turns off path showing\n1 turns on path showing\n");
		return;
	}
	l = argv[1][0] - '0';
	if (argv[1][1] != 0 || l < 0 || l > 1){
		printf("Wrong number\n");
		return;
	}
	else
		*spath = l;
}

void help (char **argv){
	if (fork() == 0){
		execlp("less", "less", "help", NULL);
		perror("execlp");
		exit(EXIT_FAILURE);
	}
	else
		wait(NULL);
}

void exe (char **argv){
	if (fork() == 0){
		execvp(argv[0], argv);
		perror("execvp");
		exit(EXIT_FAILURE);
	}
	else
		wait(NULL);
}

void ptab (int ile){
	int i;
	for (i=0; i<ile; i++)
		printf("    |");
}

void tree (char **argv, char * directory){
	if (argv[1] != NULL && argv[2] != NULL){
		printf("Too many arguments\nshowtree takes no arguments \nor exacly 1 argument for desired directory\n");
		return;
	}
	else{
		if (fork() == 0){
			DIR *d;
			struct dirent *ent;
			char ndr[max];
			int tab = 0;

			if (argv[1] != NULL && argv[2] == NULL){ /*jeden argument*/
				cd(argv);
				getcwd(ndr, sizeof(ndr));
			}
			else
				strcpy(ndr, directory);
			printf("Content of: %s\n", ndr);

			if ((d = opendir(ndr)) != NULL){ /*wchodzimy do katalogu*/
				while ((ent = readdir(d)) != NULL){ /*czytamy zawartosc*/
					char *name = ent->d_name;
					if (!(!strcmp(name, ".") || !strcmp(name, ".."))){ /*jesli nazwa rozna od . lub .. */
						if (fork()==0){
							if (chdir(name) == 0){ /*udalo nam sie wejsc do katalogu*/
								closedir(d);
								ptab(tab);
								printf("\033[1;34m%s\033[0m\n", name);
								getcwd(ndr, sizeof(ndr)); /*zmieniamy directory*/
								d = opendir(ndr);
								tab++;
							}
							else{
								ptab(tab);
								printf("%s\n", name);
								exit(0);
							}
						}
						else
							wait(NULL);
					}
				}
				closedir(d);
			}
			exit(0);
		}
		else{
			wait(NULL);
			return;
		}
	}
}

void mycp (char **argv){
	if (argv[1] == NULL || argv[2] == NULL){
		printf("Add arguments\n");
		return;
	}
	else if (argv[3] != NULL){
		printf("Too many arguments\n");
		return;
	}
	else{
		int file1 = open(argv[1], O_RDONLY);
		if (file1 == -1){
			perror("open error");
			return;
		}
		if (open(argv[2], O_RDONLY) != -1){
			printf("%s already exists!\n", argv[2]);
			return;
		}
		int newfile = creat(argv[2], 0666);
		if (newfile == -1){
			perror("create error");
			return;
		}

		char bufor[1024];
		int r;
		while ((r = read(file1, bufor, sizeof(bufor))) > 0)
			write(newfile, bufor, r);

		close(file1);
		close(newfile);
	}
}

void myps (char **argv){
	if (fork() == 0){
		if (chdir("/proc") != 0){
			perror("cant open /proc");
			exit(0);
		}
		else{ /*weszlismy w 1 fork do katalogu proc */
			DIR *d;
			struct dirent *ent;
			int i, p;

			if ((d = opendir("/proc")) != NULL){ /*otwieramy proc*/
				while ((ent = readdir(d)) != NULL){ /*czytamy zawartosc*/
					char *name = ent->d_name;
					p=0;
					for (i=0; i<strlen(name); i++)
					 	if (!isdigit(name[i])){
							p=1;
							break;
						}
					if(p)
						continue; /*jesli nie jest liczba to idziemy dalej*/

					char *direc;
					direc = (char*)malloc((strlen(name) + 10) * sizeof(char));
					direc[0] = '\0';
					strcat(direc, "./");
					strcat(direc, name);
					strcat(direc, "/status"); /*tworzenie sciezki*/

					if (fork() == 0){
						printf("Pid: %s  ", name);
						exit(0);
					}
					else
						wait(NULL);

					if (fork() == 0){
						execlp("sed", "sed", "-n", "1p", direc, NULL);
					}
					else
						wait(NULL);
				}
			}
		}
		exit(0);
	}
	else
		wait(NULL);
}

int main (){
	int spath = 1, i=0;
	using_history();
	struct passwd *p = getpwuid(getuid());

	while (1){
		char *argv[100];
		char *komenda, *prompt, directory[max];

		if (getcwd(directory, sizeof(directory)) == NULL){
			perror("getcwd() error");
			return -1;
		}

		if (spath){
			prompt = (char*)malloc(strlen(directory)+strlen(p->pw_name)+22 *sizeof(char));
			prompt[0]='\0';
			strcat(prompt, "\033[1;32m");
			strcat(prompt, "[");
			strcat(prompt, directory);
			strcat(prompt, "]\033[0m");
			strcat(prompt, p->pw_name);
		}
		else{
			prompt = (char*)malloc(strlen(p->pw_name)+3 *sizeof(char));
			strcat(prompt, p->pw_name);
		}
		strcat(prompt, "$ ");

		if (!(komenda = readline(prompt)))
			break;
		if (komenda[0] == 0)
			continue;

		add_history(komenda);
		cut(argv, komenda);
		while (argv[i] != NULL){
			rmChar(argv[i], 34);
			i+=1;
		}
		i=0;

		if (argv[0]==NULL)
			continue;
		else if (!strcmp(argv[0], "spath")){
			spathf(argv, &spath);
			continue;
		}
		else if (!strcmp(argv[0], "cd")){
			cd(argv);
			continue;
		}
		else if (!strcmp(argv[0], "help")){
			help(argv);
			continue;
		}
		else if (!strcmp(argv[0], "showtree")){
			tree(argv, directory);
			continue;
		}
		else if (!strcmp(argv[0], "mycp")){
			mycp(argv);
			continue;
		}
		else if (!strcmp(argv[0], "showps")){
			myps(argv);
			continue;
		}
		else if (!strcmp(argv[0], "exit"))
			break;
		else
			exe(argv);

		free(komenda);
		free(prompt);
	}
	return 0;
}