#include <stdio.h>
#include "file.h"
#include "audit.h"

/*
 * This function check the ownership of the file
 * If the owner is root, the audit test fail
 * Return the struct st_audit which contain the result
 */
struct st_audit ownership(uid_t uid, char *username, size_t len){
    struct st_audit st_audit;
    get_username(uid, username);
    if (strncmp(username, "root", 64) == 0){
        //printf("The %s account is not recommended. You should change the owner.\n", username);
        char result[BUF_SIZE_AUDIT];
        sprintf(st_audit.result, "The account %s is not recommended. You should change the owner.", username);
        st_audit.audit = FALSE;
    }
    else{
        //printf("The owner of the file is not root, it's recommended.\n");
        sprintf(st_audit.result, "Audit passed with success. The owner of the file isn't root.");
        st_audit.audit = TRUE;
    }
    return st_audit;
}
/*
 * This function check the permission of the file
 * Return the struct st_audit which contain the result
 * https://www.man7.org/linux/man-pages/man2/chmod.2.html
 */
void permission(mode_t mode, struct st_audit *st_audit_owner, struct st_audit *st_audit_group, struct st_audit *st_audit_other){

    /* Owner */
    int irusr = mode & S_IRUSR;
    int iwusr = mode & S_IWUSR;
    int ixusr = mode & S_IXUSR;
    if (irusr == 0 && iwusr == 0) {
        sprintf(st_audit_owner->result, "Audit passed with success. Only the owner has the privilege to read/write the file.");
        st_audit_owner->audit = TRUE;
    }
    else if (ixusr != 0){
        sprintf(st_audit_owner->result, "The file can be executabled for the owner. The permission should be removed.");
        st_audit_owner->audit = FALSE;
    }
    else{
        sprintf(st_audit_owner->result, "The certificate has the correct permission for the owner.");
        st_audit_owner->audit = TRUE;
    }

    /* Group */
    int irgrp = mode & S_IRGRP;
    int iwgrp = mode & S_IWGRP;
    int ixgrp = mode & S_IXGRP;
    if (irgrp != 0 || iwgrp != 0 || ixgrp != 0){
        sprintf(st_audit_group->result, "The group has the permission to manipulate the file. Should be removed.");
        st_audit_group->audit = FALSE;
    }
    else
        st_audit_group->audit = TRUE;

    /* Other */
    int iroth = mode & S_IROTH;
    int iwoth = mode & S_IWOTH;
    int ixoth = mode & S_IXOTH;
    if (iroth != 0 || iwoth != 0 || ixoth != 0){
        sprintf(st_audit_other->result, "The other has the permission to manipulate the file. Should be removed.");
        st_audit_other->audit = FALSE;
    }
    else
        st_audit_other->audit = TRUE;
}
/*
 * This function convert the mode_t value to human-readable value
 */
int convert_mode_t(mode_t mode){
    int perm = 0;

    /* Owner */
    if (mode & S_IRUSR)
        perm += 400;
    if (mode & S_IWUSR)
        perm += 200;
    if (mode & S_IXUSR)
        perm += 100;
    /* Group */
    if (mode & S_IRGRP)
        perm += 40;
    if (mode & S_IWGRP)
        perm += 20;
    if (mode & S_IXGRP)
        perm += 10;
    /* Other */
    if (mode & S_IROTH)
        perm += 4;
    if (mode & S_IWOTH)
        perm += 2;
    if (mode & S_IXOTH)
        perm += 1;

    return perm;
}
/*
 * This function retrieve the username from the uid_t passed in argument
 */
static void get_username(uid_t uid, char *username){
    struct passwd *p;
    p = getpwuid(uid);
    if (p == NULL){
        //printf("Failed to get the username from the UID\n");
        strncpy(username, "Unknown", 8);
        return;
    }
    strncpy(username, p->pw_name, 64);
}