/*-
 * Copyright (c) 2012 valsorym <valsorym.e@gmail.com>.
 * All rights reserved.
 * 
 * Discussion on the forums.freebsd.org.
 *  url: http://forums.freebsd.org/showthread.php?p=177208
 */
 
/*
 * Very simple class, for example OOD in ANSI C.
 */

#include <stdio.h>
#include <string.h> 
#include <memory.h>

#include "employee.h"
 
/* INTERFACES */
/* Private:
 * For the experiment, the method of Private.
 */
static int goodage(int );

/* Public: */
/* Constructor & Destructor */
static struct w_employee *create(int , char *, char *);
static void destroy(struct w_employee *);

static char *setpost(struct w_employee *, char *);
static char *getpost(struct w_employee *);

/* w_human methods. */
static int  setage(struct w_employee *, int );
static int  getage(struct w_employee *);
static char *setname(struct w_employee *, char *);
static char *getname(struct w_employee *);

/* Initialization (constructor / destructor). */
const struct w_employee_vtable w_employee = {
    .create = create,   .destroy = destroy,
    .setpost = setpost, .getpost = getpost,
    
    .setage  = setage,  .getage  = getage,
    .setname = setname, .getname = getname
};

/* IMPLEMENTATIONS */
/* Private: */
/*
 * In this class, the method gooage() determines whether the normal
 * age of a person.
 */
static int
goodage(int age)
{
    /*
     * Under the legislation an employee must be between the ages of 
     * 18 to 60 years.
     */
    if (age >= 18 && age <= 60)
        return 1;
        
    return 0;
}

/* Public: */
/*
 * The constructor, allocates memory to accommodate the class, 
 * initialize its elements. 
 */
static struct w_employee 
*create(int age, char *name, char *post)
{
    struct w_employee *self = 
        (struct w_employee *)malloc(sizeof(struct w_employee));
   
    /* Initialize the elements. */    
    /* Private data. */
    if (goodage(age) == 0)
        age = 18;

    self->human = w_human.create(age, name);
    w_employee.setpost(self, post);

    return self;
}

/*
 * The destructor frees the allocated memory in self class.
 */
static void
destroy(struct w_employee *self)
{
    if (self) {
        if (self->human)
            w_human.destroy(self->human);

        if (self->post) 
            free(self->post);

        free(self);
    }
}

/*
 * Set the post of employee.
 */
static char 
*setpost(struct w_employee *self, char *post)
{
    int post_len = strlen(post) + 1;

    if (self) {
        if (self->post)
            free(self->post);
            
        self->post = (char *)malloc(post_len * sizeof(char));
        strncpy(self->post, post, post_len);
        
        return self->post;
    }
    
    return NULL;
}

/*
 * Get the post of employee.
 */
static char
*getpost(struct w_employee *self)
{
    if (self)
        return self->post;
        
    return NULL;
}

/*
 * Set a person's age.
 */
static int
setage(struct w_employee *self, int age)
{
    if (self && self->human) {
        if (goodage(age) == 0) /* Use function of private sector. */
            return 0;
        
        w_human.setage(self->human, age);
        return w_human.getage(self->human);
    }

    return 0;
}

/*
 * Get the person's age.
 */
static int
getage(struct w_employee *self)
{
    if (self && self->human)
        return w_human.getage(self->human);
        
    return 0;
}

/*
 * Set the name of the person.
 */
static char 
*setname(struct w_employee *self, char *name)
{
    if (self && self->human) {
        w_human.setname(self->human, name);
        return w_human.getname(self->human);
    }
    
    return NULL;
}

/*
 * Get the name of the person.
 */
static char
*getname(struct w_employee *self)
{
    if (self && self->human)
        return w_human.getname(self->human);
        
    return NULL;
}

/* The End. */