/* Authors:
Laura Manninen and Joni Suomalainen

27.11.2015 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <limits.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <glob.h>
#include <unistd.h>
#include <ctype.h>

#define LOGOUT 100
#define MAXNUM 40
#define MAXLEN 160
#define die(msg) do {perror(msg); exit(EXIT_FAILURE);} while (0);

void sighandler(int sig)
{
        switch (sig) {
                case SIGALRM:
                        printf("\nautologout\n");
                        exit(0);
                default:
                        break;
        }
        return;
}
/*reding history file*/
void histRead(char* currentdir){
        char* line;
        size_t len = 0;
        ssize_t read;
        int id = 1;
        FILE *filee;

        filee = fopen(currentdir, "r");
        while((read = getline(&line, &len, filee)) != -1) {
                printf("%d %s", id,  line);
                id ++;
        }
        fclose(filee);
}
/*Reads specified command from history*/
char* historynum(int i, char* currentdir) {

        char* line;
        size_t len = 0;
        ssize_t read;
        int j = 1;
        char * cmd;
        int pid;

        FILE *file2;
        file2 = fopen(currentdir, "r");
        while((read = getline(&line, &len, file2)) != -1) {
                if (i==j) {
                        printf("%s", line);
                        cmd = line;
                break;
                }
            else {
                        j++;
                }

    }
    fclose(file2);
    return cmd;
}

int main(void)
{
        char * cmd, line[MAXLEN], * args[MAXNUM];
        int background;
    int i = 0;
        int pid;
        char buff[PATH_MAX + 1];
        char* cwd;
        char buf[512];
        char* histline;
        int cmd_in = 0;
        FILE *f;

        signal(SIGALRM, sighandler);
        signal(SIGINT, sighandler);

        char currentdir[1234];

        if ((getcwd(currentdir, sizeof(currentdir)) != NULL))
                strcat(currentdir, "/history.txt");

        while (1) {
                int argc = i;
                int k = 0;
                int output_mode = 0;
                int input_mode = 0;
                char input[MAXNUM];
                char output[MAXNUM];
                char pipeput[MAXNUM];
                background = 0;

                cwd = getcwd(buff, PATH_MAX + 1);

                /* print the prompt */

                if (cwd != NULL) {
                        printf("%s ", cwd);
                };
                /* set the timeout for alarm signal (autologout) */
                alarm(LOGOUT);

                /* read the users command */
                if (fgets(line,MAXLEN,stdin) == NULL) {
                        printf("\nlogout\n");
                        exit(0);
                }

                line[strlen(line) - 1] = '\0';

                if (strlen(line) == 0)
                        continue;

                /* start to background? */
                if (line[strlen(line)-1] == '&') {
                        line[strlen(line)-1] = 0;
                        background = 1;
                }

                /* write history log */

                if (strlen(line) != 0) {
                        FILE* file3 = fopen(currentdir, "a");
                        fprintf(file3, "%s\n", line);
                        fclose(file3);
                }

                /*check if there is pipe and splits the command line */
                i = 0;
                cmd = line;

                if((strchr(line, '|'))!=NULL){
                        while ( (args[i] = strtok(cmd, "|")) != NULL) {
                                i++;
                                cmd = NULL;
                                //break;
                        }
                        args[0][strlen(args[0]) - 1] = '\0';
                        args[1] = args[1] + 1;
                        printf("arg 0: %s\n", args[0]);
                        printf("arg 1: %s\n", args[1]);
                        FILE *pipein, *pipeout;
                        char readbuf[80];
                        /* PIPE with popen */
                        pipein = popen(args[0], "r");
                        pipeout = popen(args[1], "w");

                        while(fgets(readbuf, 80, pipein)){
                                fputs(readbuf, pipeout);
            }
                        pclose(pipein);
                        pclose(pipeout);
                        continue;
                }
                else{
                        while ( (args[i] = strtok(cmd, " ")) != NULL) {
                                printf("arg %d: %s\n", i, args[i]);
                                i++;
                                cmd = NULL;
                        }
                }

                int cmd_in = 0;
                /*executes the specified command from history again*/
                if (strlen(args[0]) >= 2 && args[0][0] == '!' && atoi(args[0]+1)) {
                        int i = atoi(args[0]+1);
                        histline = historynum(i, currentdir);
                        histline[strlen(histline) - 1] = '\0';
                        if((strchr(histline, '|'))!=NULL) {
                                while ( (args[i] = strtok(cmd, "|")) != NULL) {
                                        i++;
                                        cmd = NULL;
                                }
                                args[0][strlen(args[0]) - 1] = '\0';
                                args[1] = args[1] + 1;
                        }
                        else {

                                while ( (args[cmd_in] = strtok(histline, " ")) != NULL) {
                                        printf("arg %d: %s\n", cmd_in, args[cmd_in]);
                                        cmd_in++;
                                        histline = NULL;
                                }
                        }

                }

        /*checks if there is redirect and also if there is wildcard*/
                int bonari = 0;
                while(args[k] != NULL){
                        if(strcmp(args[k], "<") == 0){
                                input_mode = 1;
                                args[k] = NULL;
                                strcpy(input, args[k+1]);

                        }else if(strcmp(args[k], ">") == 0){
                                output_mode = 1;
                                args[k] = NULL;
                                strcpy(output, args[k+1]);
                        }else if (strstr(args[k], "*") != NULL) {
                                bonari = 1;
                        }
                        k++;
                }

                if (strcmp(args[0],"exit")==0) {
                        exit(0);
                }


                if (strcmp(args[0], "cd")==0) {
                        if (args[1] == NULL) {
                                const char* home = getenv("HOME");
                                chdir(home);
                        }
                        char *token = args[1];
                        chdir(token);
                        continue;
                }

                /* print history log */
                if (strcmp(args[0],"history")==0) {
                        histRead(currentdir);
                        continue;
                }

        /* wildcard bonus feature*/
                int jj;
                glob_t globbuf;
                if (bonari == 1){
                        for (jj = 0; jj < argc; jj++) {
                                if (jj == 0)
                                        glob(args[0],GLOB_NOCHECK, NULL, &globbuf);
                                else
                                        glob(args[jj], GLOB_NOCHECK | GLOB_APPEND, NULL, &globbuf);
                        }

                }

                char reout;
                char rein;

                switch (pid = fork()) {

                        case -1:
                                /* error */
                                perror("fork");
                                continue;
                        case 0:
                                /* child process */
                /*Redirect*/
                                if (output_mode == 1) {
                                        reout = creat(output, 0644);
                                        dup2(reout, STDOUT_FILENO);
                                        close(reout);

                                }
                                if (input_mode == 1) {
                                        rein = open(input, O_RDONLY, 0);
                                        dup2(rein, STDIN_FILENO);
                                        close(rein);
                                }
                                if (bonari == 1){
                                        execvp(&globbuf.gl_pathv[0][0], &globbuf.gl_pathv[0]);
                                        perror("execvp");
                                        exit(1);
                                }
                                else{
                                        execvp(args[0], args);
                                        perror("execvp");
                                        exit(1);
                                }
                        default:
                                /* parent (shell) */
                                if (!background) {
                                        alarm(0);
                                        while (wait(NULL)!=pid)
                                                printf("some other child process exited\n");
                                }
                                break;
                }

        }
        return 0;
}