#include <sys/wait.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>

#define LSH_TOK_BUFSIZE 64
#define LSH_TOK_DELIM " \t\r\n\a"
#define KSH_SPLIT_COMMAND ";"


char homeDir[1000],hostname[1000];



char *username;

void p(char * l) {
   printf("%s\n",l);
 }

void removeSubstring(char *s,const char *toremove)
{
  while( s=strstr(s,toremove) )
    memmove(s,s+strlen(toremove),1+strlen(s+strlen(toremove)));
}

void printStylo(char * cwd)
{
    char *temp_cwd;
    if(strstr(cwd,homeDir)!=NULL)
    {
      removeSubstring(cwd,homeDir);
    }
    fprintf(stdout, "\033[33;1m%s@%s:\033[0m\e[32m%s$\033[0m", username, hostname, cwd);
}


char *lsh_read_line(void)
{
    //printf("This is read\n");
    char *line = NULL;
    ssize_t bufsize = 0; // have getline allocate a buffer for us
    getline(&line, &bufsize, stdin);
    return line;
}

char **lsh_split_line(char *line,int flag)
{
    //printf("This is split\n");
    int bufsize = LSH_TOK_BUFSIZE, position = 0;
    char **tokens = malloc(bufsize * sizeof(char*));
    char *token;
    if (!tokens) {
        fprintf(stderr, "KShell: allocation error\n");
        exit(EXIT_FAILURE);
    }
    //printf("Line:%s",line);
    if(flag==0)
    token = strtok(line, LSH_TOK_DELIM);
    else
    token = strtok(line, KSH_SPLIT_COMMAND);
    while (token != NULL) {
        //printf("Before:%s",token);
        tokens[position] = token;
        position++;
        if (position >= bufsize) {
            bufsize += LSH_TOK_BUFSIZE;
            tokens = realloc(tokens, bufsize * sizeof(char*));
            if (!tokens) {
                fprintf(stderr, "KShell: allocation error\n");
                exit(EXIT_FAILURE);
            }
        }
        if(flag==0)
            token = strtok(NULL, LSH_TOK_DELIM);
        else
            token = strtok(NULL, KSH_SPLIT_COMMAND);
        //printf("After:%s",token);
    }
    tokens[position] = NULL;
    return tokens;
}

int lsh_launch(char **args)
{
    //printf("This is launch\n");
    pid_t pid, wpid;
    int status,bufsize=LSH_TOK_BUFSIZE;
    //printf("args:%s\n",args[0]);
    pid = fork();
    if (pid == 0) {
        // Child process
        //printf("This is child\n");
        if (execvp(args[0], args) == -1) {
            perror("KShell Error:");
        }
        exit(EXIT_FAILURE);
    } else if (pid < 0) {
        // Error forking
        perror("KShell Error");
    } else {
        //printf("This is parent\n");
        // Parent process
        do {
            wpid = waitpid(pid, &status, WUNTRACED);
        } while (!WIFEXITED(status) && !WIFSIGNALED(status));
        //exit loop if the child process terminated normally
    }
    return 1;
}

int lsh_execute(char **args)
{
    //printf("\nThis is exec args:%s\n",args[0]);
    if (args[0] == NULL) {
        // An empty command was entered.
        return 1;
    }
    if(strcmp("quit",args[0])==0){
        //printf("fu\n");
        return 0;
    }
    return lsh_launch(args);
}

int ksh_run(char **commands)
{
    int run=1,status;
    char **args;
    pid_t pid,wpid;
    for(int i=0;commands[i]!=NULL;i++)
        {
            if(strcmp("quit",commands[i])==0){
                run=0;
            }

            pid=fork();
            if(pid==0)
            {
                //printf("i:%d\ncommand:%s\n",i,commands[i]);
                args = lsh_split_line(commands[i],0);
                run=lsh_execute(args);
                exit(EXIT_FAILURE);
                printf("uff\n");
            }
        }
        do {
            wpid = waitpid(pid, &status, WUNTRACED);
        } while (!WIFEXITED(status) && !WIFSIGNALED(status));
    return run;
}

void lsh_loop(void)
{
    char *line;
    char **commands;
    int status,flag,run=1;

  char home[]="HOME:";
  if(gethostname(hostname, sizeof(hostname)) == -1)
        perror("gethostname() error\n");

  char cwd[1000];
  getcwd(cwd, 1000);

  strcat(home,cwd);
  strcpy(homeDir,cwd);

  struct passwd *pass;
    pass = getpwuid(getuid());
    username = pass->pw_name;

    do {
        flag=1;
        printStylo(cwd);
        line = lsh_read_line();
        commands=lsh_split_line(line,1);
        run=ksh_run(commands);
    } while (run);
}

int main(int argc, char **argv)
{
    //printf("This is main\n");
    lsh_loop();
    return EXIT_SUCCESS;
}