/* 
 * File:   mysh.c
 * Author: Arthur Brandao
 *
 * Created on 31 octobre 2018, 12:43
 */
#define _POSIX_C_SOURCE 2

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <wait.h>
#include <signal.h>
#include "error.h"
#include "str.h"
#include "parser.h"
#include "command.h"
#include "execute.h"
#include "mysh.h"

/* --- Extern --- */
extern Error error;
extern boolean exitsh;

/* --- Global --- */
pid_list pidlist;
pid_node* active = NULL;
int job = 1;

/* --- Fonctions privées --- */
void test_write() {
    char* a = "azerty\n";
    int tmp = write(1, a, strlen(a));
    printf("%d\n", tmp);
}

void test_tmp_file(){
    int a;
    FILE* f = tmpfile();
    printf("F : %d\n", f == NULL);
    int fd = fileno(f);
    printf("%d : %ld\n", fd, write(fd, "bonjour", 8));
    a = lseek(fd, 0L, SEEK_SET);
    sleep(2);
    char buf[10];
    memset(buf, 0 , 10);
    a = read(fd, buf, 10);
    printf("%d : %s\n", a, buf);
    close(fd);
}

void test(){
    CommandTab ct;
    char str[BUFFER_SIZE];
    int a;
    //Initialisation structures
    error_finit("mysh.log");
    ini_pid_list(&pidlist);
    
    //Recup ligne
    //printf("%s\n", fgets(str, 500, stdin));&
    memset(str, 0, 500);
    a = read(STDIN, str, 500);
    printf("%s\n", str);
    //Separe les commandes
    a = parse_line(&ct, str);
    if(a == SHELL_ERR){
        addserror("Erreur lors du parse de la ligne");
        error.exit_err();
    }
    //Parse les commandes
    a = parse_all_command(&ct);
    if(a == SHELL_FAIL){
        addserror("Erreur lors du parse des commandes");
        error.exit_err();
    }
    //Affiche resultat
    for (int i = 0; i < ct.length; i++) {
        Command* c = ct.cmd[i];
        printf("Commande %d (%s) : \n", i, c->name);
        for (int j = 0; j < c->argc; j++) {
            printf("    Argument %d : %s\n", j, c->argv[j]);
        }
        printf("Commande en fond : %d\n\n", ct.bck);
        //Si c'est une commande interne on l'execute
        if(is_internal_cmd(ct.cmd[i]->name)){
            show_current_dir(NULL, "\n");
            printf("Result : %d\n", launch_internal_command(ct.cmd[i]));
            show_current_dir(NULL, "\n");
        }
    }
    //Nettoyage structures
    clean_command(&ct);
    clean_pid(&pidlist);
    error.exit();
}

/* --- Fonctions utilitaires --- */
void show_current_dir(const char* before, const char* after) {
    char buffer[BUFFER_SIZE];
    if (getcwd(buffer, sizeof (buffer)) == NULL) {
        addperror("Erreur getcwd()");
    } else {
        if(before == NULL && after == NULL){
            printf("%s", buffer);
        } else if(before == NULL){
            printf("%s%s", buffer, after);
        } else if(after == NULL){
            printf("%s%s", before, buffer);
        } else {
            printf("%s%s%s", before, buffer, after);
        }
    }
    fflush(stdout);
}

int get_line(char* buffer){
    memset(buffer, 0, BUFFER_SIZE);
    if(read(STDIN, buffer, BUFFER_SIZE) == ERR){
        addperror("Impossible de lire dans STDIN");
        return SHELL_ERR;
    }
    return SHELL_OK;
}

int get_tmp_file(){
    FILE* f = tmpfile();
    if(f == NULL){
        adderror("Impossible de créer un fichier temporaire");
        return SHELL_ERR;
    }
    return fileno(f);
}

/* --- Main --- */
int main(int argc, char* argv[]) { 
    //Declaration variables
    CommandTab ct;
    int result;
    char line[BUFFER_SIZE], before[BUFFER_SIZE];
    sigset_t sigs_new, sigs_old, sigs_block;
    //Initialisation structures
    error_finit("mysh.log");
    ini_pid_list(&pidlist);
    //Preparation affichage
    sprintf(before, "\x1b[32m%s:\x1b[36m", getlogin());
    //Traitement des signeaux
    result = sigemptyset(&sigs_new);
    if(result == ERR){	
	addperror("Impossible de récuperer un ensemble de signaux vide");
        error.print("Erreur pendant l'initialisation\n");
        clean_pid(&pidlist);
        error.exit_err();
    }
    //On bloque que sigchld
    result = sigaddset(&sigs_new, SIGCHLD);
    if(result == -1){
	addperror("Impossible d'ajouter SIGCHLD à l'ensemble de signaux");
        error.print("Erreur pendant l'initialisation\n");
        clean_pid(&pidlist);
        error.exit_err();
    }
    result = sigprocmask(SIG_BLOCK, &sigs_new, &sigs_old);
    if(result == -1){
	addperror("Impossible de bloquer les signaux de l'ensemble");
        error.print("Erreur pendant l'initialisation\n");
        clean_pid(&pidlist);
        error.exit_err();
    }
    //Boucle infini de lecture
    while(!exitsh){
        //On regarde si un fils en fond est mort
	if(sigpending(&sigs_block) == ERR){
            addperror("Impossible de recuperer les signaux en attentes");
	} else if(sigismember(&sigs_block, SIGCHLD)){
            job--;
	}
        //Affichage repertoire
        show_current_dir(before, ">\x1b[0m ");      
        //Lecture ligne
        if(get_line(line) == SHELL_ERR){
            error.print("Impossible de lire les commandes\n");
            clean_pid(&pidlist);
            error.exit_err();
        }
        //Parse la ligne et commandes
        result = parse_line(&ct, line);
        if(result == SHELL_ERR){
            error.print("Impossible d'analyser la ligne\n");
            addserror("Erreur lors du parse de la ligne");
            continue;
        }
        //Si aucune commande on passe
        printf("Nb cmd : %d\n", ct.length);
        if(ct.length == 0){
            clean_command(&ct);
            continue;
        }
        //Parse les commandes
        result = parse_all_command(&ct);
        if(result == SHELL_FAIL){
            error.print("Impossible d'analyser la commande\n");
            addserror("Erreur lors du parse des commandes");
            continue;
        }
        //Execute
        result = run(ct, NULL);
        printf("Result : %d\n", result);
        //Vide le resultat du parse de la ligne de commande
        clean_command(&ct);
    }
    //Nettoyage
    clean_pid(&pidlist);
    error.end();
    return EXIT_SUCCESS;
}

int run(CommandTab ct, int* status){
    pid_t pid;
    int result = 0;
    //Si en fond creation d'un fork pour executer les commandes
    printf("bck : %d\n", ct.bck);
    if(ct.bck){
        pid = fork();
        if(pid == ERR){
            addperror("Erreur lors du fork pour l'execution des commandes");
            error.print("Erreur systeme, impossible de continuer\n");
            return SHELL_ERR;
        }
        //Fils
        if(pid == 0){
            int stat = 0;
            ct.bck = 0;
            result = run(ct, &stat);
            //Message de fin + retour
            if(result == SHELL_FAIL){
                printf("\n%s (jobs=[%d], pid=%d) terminée avec status=-1\n", ct.line, job, getpid());
                exit(EXIT_FAILURE);
            }
            printf("\n%s (jobs=[%d], pid=%d) terminée avec status=%d\n", ct.line, job, getpid(), stat);
            exit(EXIT_SUCCESS);
        }
        printf("[%d] %d\n", job, pid);
        //Ajout du fils dans la liste des pid
        add_pid(&pidlist, pid, job++);
        //Pour le pere c'est fini
        return SHELL_OK;
    }
    //Sinon execution de chaque commande
    Command* c;
    int tube[ct.length][2];
    int tubepos = 0;
    int infd = -1, outfd = -1, errfd = -1;
    boolean bpipe = false, skippipe = false, skip = false;
    //Parcours les commandes
    for(int i = 0; i < ct.length; i++){
        c = ct.cmd[i];
        //Si on skip
        if(skip){
            skip = false;
            continue;
        }
        //Si pipe avant
        if(skippipe){
            //Si fin chaine pipe
            if(c->next != SHELL_PIPE){
                skippipe = false;
            }
            //Passe la commande
            continue;
        }
        //Si pipe creation d'un fichier commun
        skippipe = c->next == SHELL_PIPE ;
        if(c->next == SHELL_PIPE && c->output == STDOUT){
            skippipe = false;
            bpipe = true;
            //Creation tube
            if(pipe(tube[tubepos]) == ERR){
                addperror("Impossible de créer un tube");
                return SHELL_FAIL;
            }
            //Redirection
            c->output = tube[tubepos][TUBE_ECRITURE];
            if(ct.cmd[i + 1]->input == STDIN){
                ct.cmd[i + 1]->input = tube[tubepos][TUBE_LECTURE];
            }
        }
        //Effectue les redirections IO
        if(c->input != STDIN){
            infd = redirect_fd2(STDIN, c->input);
            if(infd == ERR){
                return SHELL_FAIL;
            }
        }
        if(c->output != STDOUT){
            outfd = redirect_fd2(STDOUT, c->output);
            if(outfd == ERR){
                return SHELL_FAIL;
            }
        }
        if(c->error != STDERR){
            errfd = redirect_fd2(STDERR, c->error);
            if(errfd == ERR){
                return SHELL_FAIL;
            }
        }
        //Execute la commande
        if(is_internal_cmd(c->name)){
            result = launch_internal_command(c);
        } else if(is_executable_file(c->name)){
            result = exec_file(c->name, c->argv);
        } else {
            result = exec_shell(c->name, c->argv);
        }
        //Si on a une variable pour stocker le status de retoure
        if(status != NULL){
            *status = result;
        }
        //Reset IO
        if(c->input != STDIN){
            infd = redirect_fd(STDIN, infd);
            if(infd == ERR){
                return SHELL_FAIL;
            }
        }
        if(c->output != STDOUT){
            outfd = redirect_fd(STDOUT, outfd);
            if(outfd == ERR){
                return SHELL_FAIL;
            }
        }
        if(c->error != STDERR){
            errfd = redirect_fd(STDERR, errfd);
            if(errfd == ERR){
                return SHELL_FAIL;
            }
        }
        //Fermeture tube
        if(bpipe){
            bpipe = false;
            if(close(outfd) == ERR){
                addperror("Impossible de fermer tube ecriture");
                return SHELL_FAIL;
            }
            if(close(c->output) == ERR){
                addperror("Impossible de fermer tube ecriture");
                return SHELL_FAIL;
            }
            c->output = STDOUT;
        }
        //Agit en fonction de la jointure avec la prochaine commande
        if(c->next == SHELL_IF){
            if(result != EXIT_SUCCESS){
                skip = true;
            }
        } else if(c->next == SHELL_ELSE){
            if(result == EXIT_SUCCESS){
                skip = true;
            }
        }
    }
    if(result != EXIT_SUCCESS){
        return SHELL_FAIL;
    }
    return SHELL_OK;
}