/*****************************************************************************
 * var_tree.hpp
 *****************************************************************************
 * Copyright (C) 2005 VideoLAN
 * $Id$
 *
 * Authors: Antoine Cellerier <dionoea@videolan.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifndef VAR_TREE_HPP
#define VAR_TREE_HPP

#include <list>

#include "variable.hpp"
#include "observer.hpp"
#include "ustring.hpp"
#include "var_percent.hpp"

/// Description of an update to the tree
typedef struct tree_update
{
     int i_type;
     int i_parent;
     int i_id;
     bool b_active_item;
     bool b_visible;
} tree_update;

/// Tree variable
class VarTree: public Variable, public Subject<VarTree, tree_update*>
{
    public:
        VarTree( intf_thread_t *pIntf );

        VarTree( intf_thread_t *pIntf, VarTree *pParent, int id,
                 const UStringPtr &rcString, bool selected, bool playing,
                 bool expanded,bool readonly, void *pData );

        virtual ~VarTree();

        /// Get the variable type
        virtual const string &getType() const { return m_type; }

        /// Add a pointer on string in the children's list
        virtual void add( int id, const UStringPtr &rcString, bool selected,
                          bool playing, bool expanded, bool readonly,
                          void *pData );

        /// Remove the selected item from the children's list
        virtual void delSelected();

        /// Remove all elements from the children's list
        virtual void clear();

        /// \todo Use accessors for these fields ?
        int m_id;
        UStringPtr m_cString;
        bool m_selected;
        bool m_playing;
        bool m_expanded;
        bool m_deleted;
        void *m_pData;

        inline bool isReadonly() { return m_readonly; };

        /// Get the number of children
        int size() const { return m_children.size(); }

        /// Iterators
        typedef list<VarTree>::iterator Iterator;
        typedef list<VarTree>::const_iterator ConstIterator;

        /// Begining of the children's list
        Iterator begin() { return m_children.begin(); }
        ConstIterator begin() const { return m_children.begin(); }

        /// End of children's list
        Iterator end() { return m_children.end(); }
        ConstIterator end() const { return m_children.end(); }

        /// Back of children's list
        VarTree &back() { return m_children.back(); }

        /// Return an iterator on the n'th element of the children's list
        Iterator operator[]( int n );
        ConstIterator operator[]( int n ) const;

        /// Parent node
        VarTree *parent() { return m_pParent; }
        void checkParents( VarTree *pParent );

        /// Get next sibling
        Iterator getNextSibling( Iterator );

        Iterator next_uncle();
        Iterator prev_uncle();

        /// Get root node
        VarTree *root()
        {
            VarTree *parent = this;
            while( parent->parent() != NULL )
                parent = parent->parent();
            return parent;
        }

        /// Get depth (root depth is 0)
        int depth()
        {
            VarTree *parent = this;
            int depth = 0;
            while( ( parent = parent->parent() ) != NULL )
                depth++;
            return depth;
        }

        void removeChild( VarTree::Iterator item )
        {
            m_children.erase( item );
        }

        /// Execute the action associated to this item
        virtual void action( VarTree *pItem ) {}

        /// Get a reference on the position variable
        VarPercent &getPositionVar() const
        { return *((VarPercent*)m_cPosition.get()); }

        /// Get a counted pointer on the position variable
        const VariablePtr &getPositionVarPtr() const { return m_cPosition; }

        /// Count the number of items that should be displayed if the playlist window wasn't limited
        int visibleItems();

        /// Return iterator to the n'th visible item
        Iterator getVisibleItem( int n );

        /// Given an iterator to a visible item, return the next visible item
        Iterator getNextVisibleItem( Iterator it );

        /// Given an it to a visible item, return the previous visible item
        Iterator getPrevVisibleItem( Iterator it );

        /// Given an iterator to an item, return the next item
        Iterator getNextItem( Iterator it );

        /// Find a children node with the given id
        Iterator findById( int id );

        /// Ensure an item is expanded
        void ensureExpanded( VarTree::Iterator );

    private:
        /// List of children
        list<VarTree> m_children;

        /// Pointer to parent node
        VarTree *m_pParent;

        bool m_readonly;

        /// Variable type
        static const string m_type;

        /// Position variable
        VariablePtr m_cPosition;
};

#endif
