// ================================================================================
// ==      This file is a part of Turbo Badger. (C) 2011-2014, Emil Segerås      ==
// ==                     See tb_core.h for more information.                    ==
// ================================================================================

#ifndef TB_NODE_REF_TREE_H
#define TB_NODE_REF_TREE_H

#include "tb_linklist.h"
#include "tb_node_tree.h"
#include "tb_id.h"

namespace tb {

class TBNode;
class TBNodeRefTreeListener;

/** TBNodeRefTree is a named TBNode.
    Nodes under this node may be referenced from other nodes, either when
    requesting a value (TBNode::GetValueFollowRef), or while parsing the
    node tree. While parsing, the values can be used for branch conditions
    or branches of nodes can be included. */
class TBNodeRefTree : public TBLinkOf<TBNodeRefTree>
{
public:
    TBNodeRefTree(const char *name);
    virtual ~TBNodeRefTree();

    const char *GetName() const { return m_name; }
    const TBID &GetNameID() const { return m_name_id; }

    /** Read the data file. This will *not* invoke any change listener! */
    bool ReadFile(const char *filename) { return m_node.ReadFile(filename); }
    void ReadData(const char *data) { m_node.ReadData(data); }

    /** Add a listener that is invoked on changes in this tree. */
    void AddListener(TBNodeRefTreeListener *listener) { m_listeners.AddLast(listener); }

    /** Remove a change listener from this tree. */
    void RemoveListener(TBNodeRefTreeListener *listener) { m_listeners.Remove(listener); }

    /** Set the value for the given request and invoke the change listener.
        Creates the nodes that doesn't exist. */
    virtual void SetValue(const char *request, const TBValue &value);

    /** Get the value of the given request. Follows references if any.
        Returns a null value if the request doesn't exist. */
    virtual TBValue &GetValue(const char *request);

    /** Get the value of the given tree name and request (@treename>noderequest).
        Returns a null value if the given tree or request doesn't exist. */
    static TBValue &GetValueFromTree(const char *request);

    /** Return the tree with the given name, or nullptr if no matching tree exists. */
    static TBNodeRefTree *GetRefTree(const char *name, int name_len);

    /** Go through the tree of nodes recursively and include
        or remove branches depending on any conditions. */
    static void ResolveConditions(TBNode *parent_node);
private:
    friend class TBNode;
    friend class TBNodeTarget;
    /** Follow any references to data trees and return the destination node.
        If there's broken references, the node will be returned. */
    static TBNode *FollowNodeRef(TBNode *node);

    void InvokeChangeListenersInternal(const char *request);
    TBNode m_node;
    TBStr m_name;
    TBID m_name_id;
    TBLinkListOf<TBNodeRefTreeListener> m_listeners;
    static TBLinkListOf<TBNodeRefTree> s_ref_trees;
};

/**	TBNodeRefTreeListener receive OnDataChanged when the
    value of a node in a TBNodeRefTree is changed.
    FIX: The listener can currently only listen to one tree. */
class TBNodeRefTreeListener : public TBLinkOf<TBNodeRefTreeListener>
{
public:
    /** Called when the value is changed for the given node
        in the given ref tree. The request is without tree name. */
    virtual void OnDataChanged(TBNodeRefTree *rt, const char *request) = 0;
};

}; // namespace tb

#endif // TB_NODE_REF_TREE_H