/*
* Copyright (C) 2010 - 2014 Eluna Lua Engine <http://emudevs.com/>
* This program is free software licensed under GPL version 3
* Please see the included DOCS/LICENSE.md for more information
*/

#ifndef _ELUNA_BINDING_H
#define _ELUNA_BINDING_H

#include "Common.h"
#include "LuaEngine.h"
#include "ElunaUtility.h"

extern "C"
{
#include "lua.h"
#include "lauxlib.h"
};

class ElunaBind
{
public:
    typedef std::pair<int, uint32> FunctionRefCounterPair; // (function reference, remaining calls counter)
    typedef std::vector<FunctionRefCounterPair> FunctionRefVector;
    typedef UNORDERED_MAP<int, FunctionRefVector> EventToFunctionsMap;

    Eluna& E;
    const char* groupName;

    ElunaBind(const char* bindGroupName, Eluna& _E) : E(_E), groupName(bindGroupName)
    {
    }

    virtual ~ElunaBind()
    {
        Clear();
    }

    // unregisters all registered functions and clears all registered events from the bindings
    virtual void Clear() { };

    // Updates the counters on all temporary bindings and erases them if the counter would reach 0.
    virtual void UpdateTemporaryBindings() { };
};

template<typename T>
class EventBind : public ElunaBind
{
public:
    EventBind(const char* bindGroupName, Eluna& _E) : ElunaBind(bindGroupName, _E)
    {
    }

    // unregisters all registered functions and clears all registered events from the bind std::maps (reset)
    void Clear() override
    {
        for (EventToFunctionsMap::iterator itr = Bindings.begin(); itr != Bindings.end(); ++itr)
        {
            for (FunctionRefVector::iterator it = itr->second.begin(); it != itr->second.end(); ++it)
                luaL_unref(E.L, LUA_REGISTRYINDEX, (*it).first);
            itr->second.clear();
        }
        Bindings.clear();
    }

    void UpdateTemporaryBindings() override
    {
        for (EventToFunctionsMap::iterator itr = Bindings.begin(); itr != Bindings.end();)
        {
            for (FunctionRefVector::iterator it = itr->second.begin(); it != itr->second.end();)
            {
                uint32 counter = (*it).second;

                if (counter > 1)
                {
                    counter--;
                    (*it).second = counter;
                    it++;
                }
                else if (counter == 1)
                {
                    luaL_unref(E.L, LUA_REGISTRYINDEX, (*it).first);
                    it = itr->second.erase(it);
                }
                else
                {
                    it++;
                }
            }

            // If there are no more entries in the vector, erase the vector.
            if (itr->second.empty())
            {
                itr = Bindings.erase(itr);
            }
            else
            {
                itr++;
            }
        }
    }

    void Insert(int eventId, int funcRef, uint32 shots) // Inserts a new registered event
    {
        Bindings[eventId].push_back(std::make_pair(funcRef, shots));
    }

    // Checks if there are events for ID
    bool HasEvents(T eventId) const
    {
        if (Bindings.empty())
            return false;
        if (Bindings.find(eventId) == Bindings.end())
            return false;
        return true;
    }

    EventToFunctionsMap Bindings; // Binding store Bindings[eventId] = {(funcRef, counter)};
};

template<typename T>
class EntryBind : public ElunaBind
{
public:
    typedef UNORDERED_MAP<uint32, EventToFunctionsMap> EntryToEventsMap;

    EntryBind(const char* bindGroupName, Eluna& _E) : ElunaBind(bindGroupName, _E)
    {
    }

    // unregisters all registered functions and clears all registered events from the bindmap
    void Clear() override
    {
        for (EntryToEventsMap::iterator itr = Bindings.begin(); itr != Bindings.end(); ++itr)
        {
            for (EventToFunctionsMap::iterator it = itr->second.begin(); it != itr->second.end(); ++it)
            {
                for (FunctionRefVector::iterator i = it->second.begin(); i != it->second.end(); ++i)
                    luaL_unref(E.L, LUA_REGISTRYINDEX, (*i).first);
                it->second.clear();
            }
            itr->second.clear();
        }
        Bindings.clear();
    }

    void UpdateTemporaryBindings() override
    {
        for (EntryToEventsMap::iterator itr = Bindings.begin(); itr != Bindings.end();)
        {
            for (EventToFunctionsMap::iterator it = itr->second.begin(); it != itr->second.end();)
            {
                for (FunctionRefVector::iterator i = it->second.begin(); i != it->second.end();)
                {
                    uint32 counter = (*i).second;
                    if (counter > 1)
                    {
                        counter--;
                        (*i).second = counter;
                        i++;
                    }
                    else if (counter == 1)
                    {
                        luaL_unref(E.L, LUA_REGISTRYINDEX, (*i).first);
                        i = it->second.erase(i);
                    }
                    else
                    {
                        i++;
                    }
                }

                // If there are no more entries in the vector, erase the vector.
                if (it->second.empty())
                {
                    it = itr->second.erase(it);
                }
                else
                {
                    it++;
                }
            }

            // If there are no more vector in the map, erase the map.
            if (itr->second.empty())
            {
                itr = Bindings.erase(itr);
            }
            else
            {
                itr++;
            }
        }
    }

    void Insert(uint32 entryId, int eventId, int funcRef, uint32 shots) // Inserts a new registered event
    {
        Bindings[entryId][eventId].push_back(std::make_pair(funcRef, shots));
    }

    // Returns true if the entry has registered binds
    bool HasEvents(uint32 entryId, int eventId) const
    {
        if (Bindings.empty())
            return false;

        EntryToEventsMap::const_iterator itr = Bindings.find(entryId);
        if (itr == Bindings.end())
            return false;

        return itr->second.find(eventId) != itr->second.end();
    }

    bool HasEvents(uint32 entryId) const
    {
        if (Bindings.empty())
            return false;

        return Bindings.find(entryId) != Bindings.end();
    }

    EntryToEventsMap Bindings; // Binding store Bindings[entryId][eventId] = {(funcRef, counter)};
};

#endif