/* -*- Mode: C; indent-tabs-mode: nil; c-basic-offset: 8 -*- */

/*
 * This file is part of The Croco Library
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2.1 of the GNU Lesser General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * See COPYRIGHTS file for copyright information.
 */

#include <string.h>
#include "cr-selector.h"
#include "cr-parser.h"

/**
 * cr_selector_new:
 *
 *@a_simple_sel: the initial simple selector list
 *of the current instance of #CRSelector.
 *
 *Creates a new instance of #CRSelector.
 *
 *Returns the newly built instance of #CRSelector, or
 *NULL in case of failure.
 */
CRSelector *
cr_selector_new (CRSimpleSel * a_simple_sel)
{
        CRSelector *result = NULL;

        result = g_try_malloc (sizeof (CRSelector));
        if (!result) {
                cr_utils_trace_info ("Out of memory");
                return NULL;
        }
        memset (result, 0, sizeof (CRSelector));
        result->simple_sel = a_simple_sel;
        return result;
}

/**
 * cr_selector_append:
 *
 *@a_this: the current instance of #CRSelector.
 *@a_new: the instance of #CRSelector to be appended.
 *
 *Appends a new instance of #CRSelector to the current selector list.
 *
 *Returns the new list.
 */
CRSelector *
cr_selector_append (CRSelector * a_this, CRSelector * a_new)
{
        CRSelector *cur = NULL;

        if (!a_this) {
                return a_new;
        }

        /*walk forward the list headed by a_this to get the list tail */
        for (cur = a_this; cur && cur->next; cur = cur->next) ;

        cur->next = a_new;
        a_new->prev = cur;

        return a_this;
}

/**
 * cr_selector_prepend:
 *
 *@a_this: the current instance of #CRSelector list.
 *@a_new: the instance of #CRSelector.
 *
 *Prepends an element to the #CRSelector list.
 * 
 *Returns the new list.
 */
CRSelector *
cr_selector_prepend (CRSelector * a_this, CRSelector * a_new)
{
        CRSelector *cur = NULL;

        a_new->next = a_this;
        a_this->prev = a_new;

        for (cur = a_new; cur && cur->prev; cur = cur->prev) ;

        return cur;
}

/**
 * cr_selector_append_simple_sel:
 *
 *@a_this: the current instance of #CRSelector.
 *@a_simple_sel: the simple selector to append.
 *
 *append a simple selector to the current #CRSelector list.
 *
 *Returns the new list or NULL in case of failure.
 */
CRSelector *
cr_selector_append_simple_sel (CRSelector * a_this,
                               CRSimpleSel * a_simple_sel)
{
        CRSelector *selector = NULL;

        selector = cr_selector_new (a_simple_sel);
        g_return_val_if_fail (selector, NULL);

        return cr_selector_append (a_this, selector);
}

guchar *
cr_selector_to_string (CRSelector const * a_this)
{
        guchar *result = NULL;
        GString *str_buf = NULL;

        str_buf = g_string_new (NULL);
        g_return_val_if_fail (str_buf, NULL);

        if (a_this) {
                CRSelector const *cur = NULL;

                for (cur = a_this; cur; cur = cur->next) {
                        if (cur->simple_sel) {
                                guchar *tmp_str = NULL;

                                tmp_str = cr_simple_sel_to_string
                                        (cur->simple_sel);

                                if (tmp_str) {
                                        if (cur->prev)
                                                g_string_append (str_buf, 
								 ", ");

                                        g_string_append (str_buf, (const gchar *) tmp_str);

                                        g_free (tmp_str);
                                        tmp_str = NULL;
                                }
                        }
                }
        }

        if (str_buf) {
                result = (guchar *) g_string_free (str_buf, FALSE);
                str_buf = NULL;
        }

        return result;
}

/**
 * cr_selector_dump:
 *
 *@a_this: the current instance of #CRSelector.
 *@a_fp: the destination file.
 *
 *Serializes the current instance of #CRSelector to a file.
 */
void
cr_selector_dump (CRSelector const * a_this, FILE * a_fp)
{
        guchar *tmp_buf = NULL;

        if (a_this) {
                tmp_buf = cr_selector_to_string (a_this);
                if (tmp_buf) {
                        fprintf (a_fp, "%s", tmp_buf);
                        g_free (tmp_buf);
                        tmp_buf = NULL;
                }
        }
}

/**
 * cr_selector_ref:
 *
 *@a_this: the current instance of #CRSelector.
 *
 *Increments the ref count of the current instance
 *of #CRSelector.
 */
void
cr_selector_ref (CRSelector * a_this)
{
        g_return_if_fail (a_this);

        a_this->ref_count++;
}

/**
 * cr_selector_unref:
 *
 *@a_this: the current instance of #CRSelector.
 *
 *Decrements the ref count of the current instance of
 *#CRSelector.
 *If the ref count reaches zero, the current instance of
 *#CRSelector is destroyed.
 *
 *Returns TRUE if this function destroyed the current instance
 *of #CRSelector, FALSE otherwise.
 */
gboolean
cr_selector_unref (CRSelector * a_this)
{
        g_return_val_if_fail (a_this, FALSE);

        if (a_this->ref_count) {
                a_this->ref_count--;
        }

        if (a_this->ref_count == 0) {
                cr_selector_destroy (a_this);
                return TRUE;
        }

        return FALSE;
}

/**
 * cr_selector_destroy:
 *
 *@a_this: the current instance of #CRSelector.
 *
 *Destroys the selector list.
 */
void
cr_selector_destroy (CRSelector * a_this)
{
        CRSelector *cur = NULL;

        g_return_if_fail (a_this);

        /*
         *go and get the list tail. In the same time, free
         *all the simple selectors contained in the list.
         */
        for (cur = a_this; cur && cur->next; cur = cur->next) {
                if (cur->simple_sel) {
                        cr_simple_sel_destroy (cur->simple_sel);
                        cur->simple_sel = NULL;
                }
        }

        if (cur) {
                if (cur->simple_sel) {
                        cr_simple_sel_destroy (cur->simple_sel);
                        cur->simple_sel = NULL;
                }
        }

        /*in case the list has only one element */
        if (cur && !cur->prev) {
                g_free (cur);
                return;
        }

        /*walk backward the list and free each "next element" */
        for (cur = cur->prev; cur && cur->prev; cur = cur->prev) {
                if (cur->next) {
                        g_free (cur->next);
                        cur->next = NULL;
                }
        }

        if (!cur)
                return;

        if (cur->next) {
                g_free (cur->next);
                cur->next = NULL;
        }

        g_free (cur);
}
