#include "Base.h"
#include "ScriptController.h"
#include "ScriptTarget.h"

namespace gameplay
{

// TODO: Handle reloading scripts and then case where EventRegistries have events added AFTER a script has been loaded (i.e. need to reload callbacks for the script).

extern void splitURL(const std::string& url, std::string* file, std::string* id);

const char* ScriptTarget::Event::getName() const
{
    return name.c_str();
}

const char* ScriptTarget::Event::getArgs() const
{
    return args.c_str();
}

ScriptTarget::EventRegistry::EventRegistry()
{
}

ScriptTarget::EventRegistry::~EventRegistry()
{
    for (size_t i = 0, count = _events.size(); i < count; ++i)
    {
        SAFE_DELETE(_events[i]);
    }
}

const ScriptTarget::Event* ScriptTarget::EventRegistry::addEvent(const char* name, const char* args)
{
    GP_ASSERT(name);

    Event* evt = new Event;
    evt->name = name;
    evt->args = args ? args : "";

    _events.push_back(evt);

    return evt;
}

unsigned int ScriptTarget::EventRegistry::getEventCount() const
{
    return _events.size();
}

const ScriptTarget::Event* ScriptTarget::EventRegistry::getEvent(unsigned int index) const
{
    GP_ASSERT(index < _events.size());

    return _events[index];
}

const ScriptTarget::Event* ScriptTarget::EventRegistry::getEvent(const char* name) const
{
    GP_ASSERT(name);

    for (size_t i = 0, count = _events.size(); i < count; ++i)
    {
        if (_events[i]->name == name)
            return _events[i];
    }

    return NULL;
}

ScriptTarget::ScriptTarget() : _scriptRegistries(NULL), _scripts(NULL), _scriptCallbacks(NULL)
{
}

ScriptTarget::~ScriptTarget()
{
    // Free callbacks
    SAFE_DELETE(_scriptCallbacks);

    // Free scripts
    ScriptEntry* se = _scripts;
    while (se)
    {
        ScriptEntry* tmp = se;
        se = se->next;

        SAFE_RELEASE(tmp->script);
        SAFE_DELETE(tmp);
    }

    // Free registry entries
    RegistryEntry* re = _scriptRegistries;
    while (re)
    {
        RegistryEntry* tmp = re;
        re = re->next;

        // Don't delete the actual EventRegistry, since it's shared by all
        // ScriptTargets of the same type
        SAFE_DELETE(tmp);
    }
}

void ScriptTarget::registerEvents(EventRegistry* registry)
{
    GP_ASSERT(registry);

    // Attach the registry
    RegistryEntry* re = new RegistryEntry(registry);
    if (_scriptRegistries)
    {
        RegistryEntry* last = _scriptRegistries;
        while (last->next)
            last = last->next;
        last->next = re;
        re->prev = last;
    }
    else
    {
        _scriptRegistries = re;
    }
}

Script* ScriptTarget::addScript(const char* path)
{
    ScriptController* sc = Game::getInstance()->getScriptController();

    // Load the script
    Script* script = sc->loadScript(path, Script::PROTECTED);
    if (!script)
        return NULL;

    // Attach the script
    ScriptEntry* se = new ScriptEntry(script);
    if (_scripts)
    {
        ScriptEntry* last = _scripts;
        while (last->next)
            last = last->next;
        last->next = se;
        se->prev = last;
    }
    else
    {
        _scripts = se;
    }

    // Inspect the loaded script for event functions that are supported by this ScriptTarget.
    // TODO: We'll need to re-load eventCallbacks when EventRegistries change for this ScriptObject.
    RegistryEntry* re = _scriptRegistries;
    while (re)
    {
        std::vector<Event*>& events = re->registry->_events;
        for (size_t i = 0, count = events.size(); i < count; ++i)
        {
            const Event* event = events[i];
            if (sc->functionExists(event->name.c_str(), script))
            {
                if (!_scriptCallbacks)
                    _scriptCallbacks = new std::map<const Event*, std::vector<CallbackFunction>>();
                (*_scriptCallbacks)[event].push_back(CallbackFunction(script, event->name.c_str()));
            }
        }
        re = re->next;
    }

    // Automatically call the 'attached' event if it is defined within the script
    if (sc->functionExists("attached", script))
    {
        char args[256];
        sprintf(args, "<%s>", getTypeName());
        sc->executeFunction<void>(script, "attached", args, dynamic_cast<void*>(this));
    }

    return script;
}

bool ScriptTarget::removeScript(const char* path)
{
    GP_ASSERT(path);

    ScriptEntry* se = _scripts;
    while (se)
    {
        if (strcmp(se->script->getPath(), path) == 0 && se->script->getScope() == Script::PROTECTED)
        {
            removeScript(se);
            return true;
        }
        se = se->next;
    }

    return false;
}

void ScriptTarget::removeScript(ScriptEntry* se)
{
    GP_ASSERT(se);

    // Link out this ScriptEntry
    if (se->prev)
        se->prev->next = se->next;
    if (se->next)
        se->next->prev = se->prev;
    if (_scripts == se)
        _scripts = se->next;

    Script* script = se->script;

    // Delete the ScriptEntry
    SAFE_DELETE(se);

    // Erase any callback functions registered for this script
    if (_scriptCallbacks)
    {
        std::map<const Event*, std::vector<CallbackFunction>>::iterator itr = _scriptCallbacks->begin();
        for ( ; itr != _scriptCallbacks->end(); ++itr)
        {
            std::vector<CallbackFunction>& callbacks = itr->second;
            std::vector<CallbackFunction>::iterator itr2 = callbacks.begin();
            while (itr2 != callbacks.end())
            {
                if (itr2->script == script)
                    itr2 = callbacks.erase(itr2);
                else
                    ++itr2;
            }
        }
    }

    // Free the script
    SAFE_RELEASE(script);
}

void ScriptTarget::addScriptCallback(const Event* event, const char* function)
{
    GP_ASSERT(event);
    GP_ASSERT(function);

    // Parse the script name (if it exists) and function out
    std::string scriptPath, func;
    splitURL(function, &scriptPath, &func);
    if (func.length() == 0)
    {
        // The url doesn't reference a script, only a function
        func = scriptPath;
        scriptPath = "";
    }

    // Have we already loaded this global script?
    bool loaded = true;
    Script* script = NULL;
    if (!scriptPath.empty())
    {
        loaded = false;
        ScriptEntry* se = _scripts;
        while (se)
        {
            if (scriptPath == se->script->getPath() && se->script->getScope() == Script::GLOBAL)
            {
                // Script is already loaded
                script = se->script;
                loaded = true;
                break;
            }
            se = se->next;
        }
    }

    if (!loaded)
    {
        // The specified global script is not yet loaded, so do so
        script = Game::getInstance()->getScriptController()->loadScript(scriptPath.c_str(), Script::GLOBAL);
        if (script)
        {
            loaded = true;
            ScriptEntry* se = new ScriptEntry(script);
            if (_scripts)
            {
                ScriptEntry* last = _scripts;
                while (last->next)
                    last = last->next;
                last->next = se;
                se->prev = last;
            }
            else
            {
                _scripts = se;
            }
        }
        else
        {
            GP_WARN("Failed to load script '%s' for script target while registering for function: %s", scriptPath.c_str(), function);
        }
    }

    if (loaded)
    {
        // Store the callback
        if (!_scriptCallbacks)
            _scriptCallbacks = new std::map<const Event*, std::vector<CallbackFunction>>();
        (*_scriptCallbacks)[event].push_back(CallbackFunction(script, func.c_str()));
    }
}

void ScriptTarget::removeScriptCallback(const Event* event, const char* function)
{
    // Parse the script name (if it exists) and function out
    std::string scriptPath, func;
    splitURL(function, &scriptPath, &func);
    if (func.length() == 0)
    {
        // The url doesn't reference a script, only a function
        func = scriptPath;
        scriptPath = "";
    }

    // Find the script entry for this callback
    ScriptEntry* scriptEntry = NULL;
    if (!scriptPath.empty())
    {
        ScriptEntry* se = _scripts;
        while (se)
        {
            if (scriptPath == se->script->getPath() && se->script->getScope() == Script::GLOBAL)
            {
                scriptEntry = se;
                break;
            }
            se = se->next;
        }
    }
    Script* script = scriptEntry ? scriptEntry->script : NULL;

    // Remove any registered callback functions that match the specified one
    int removedCallbacks = 0;
    int totalCallbacks = 0;
    if (_scriptCallbacks)
    {
        std::map<const Event*, std::vector<CallbackFunction>>::iterator itr = _scriptCallbacks->begin();
        for (; itr != _scriptCallbacks->end(); ++itr)
        {
            // Erase matching callback functions for this event
            bool forEvent = itr->first == event;
            std::vector<CallbackFunction>& callbacks = itr->second;
            std::vector<CallbackFunction>::iterator itr2 = callbacks.begin();
            while (itr2 != callbacks.end())
            {
                if (itr2->script == script)
                {
                    ++totalCallbacks; // sum total number of callbacks found for this script
                    if (forEvent && itr2->function == func)
                    {
                        itr2 = callbacks.erase(itr2);
                        ++removedCallbacks; // sum number of callbacks removed
                    }
                    else
                        ++itr2;
                }
            }
        }
    }

    // Cleanup the script if there are no remaining callbacks for it
    if (scriptEntry && (totalCallbacks - removedCallbacks) <= 0)
    {
        removeScript(scriptEntry);
    }
}

void ScriptTarget::clearScripts()
{
    while (_scripts)
    {
        removeScript(_scripts);
    }
}

bool ScriptTarget::hasScriptListener(const char* eventName) const
{
    const Event* event = getScriptEvent(eventName);
    return event ? hasScriptListener(event) : false;
}

const ScriptTarget::Event* ScriptTarget::getScriptEvent(const char* eventName) const
{
    GP_ASSERT(eventName);

    // Lookup the event for this name
    const Event* event = NULL;
    RegistryEntry* re = _scriptRegistries;
    while (re)
    {
        if ((event = re->registry->getEvent(eventName)) != NULL)
            break;
        re = re->next;
    }

    return event;
}

bool ScriptTarget::hasScriptListener(const Event* event) const
{
    GP_ASSERT(event);

    if (_scriptCallbacks)
    {
        std::map<const Event*, std::vector<CallbackFunction>>::iterator itr = _scriptCallbacks->find(event);
        if (itr != _scriptCallbacks->end())
        {
            return !itr->second.empty();
        }
    }

    return false;
}

template<> void ScriptTarget::fireScriptEvent<void>(const Event* event, ...)
{
    GP_ASSERT(event);

    if (!_scriptCallbacks)
        return; // no registered callbacks

    va_list list;
    va_start(list, event);

    // Lookup registered callbacks for this event and fire them
    std::map<const Event*, std::vector<CallbackFunction>>::iterator itr = _scriptCallbacks->find(event);
    if (itr != _scriptCallbacks->end())
    {
        ScriptController* sc = Game::getInstance()->getScriptController();
        std::vector<CallbackFunction>& callbacks = itr->second;
        for (size_t i = 0, count = callbacks.size(); i < count; ++i)
        {
            CallbackFunction& cb = callbacks[i];
            sc->executeFunction<void>(cb.script, cb.function.c_str(), event->args.c_str(), &list);
        }
    }

    va_end(list);
}

template<> bool ScriptTarget::fireScriptEvent<bool>(const Event* event, ...)
{
    GP_ASSERT(event);

    if (!_scriptCallbacks)
        return false; // no registered callbacks

    va_list list;
    va_start(list, event);

    // Lookup registered callbacks for this event and fire them
    std::map<const Event*, std::vector<CallbackFunction>>::iterator itr = _scriptCallbacks->find(event);
    if (itr != _scriptCallbacks->end())
    {
        ScriptController* sc = Game::getInstance()->getScriptController();
        std::vector<CallbackFunction>& callbacks = itr->second;
        for (size_t i = 0, count = callbacks.size(); i < count; ++i)
        {
            CallbackFunction& cb = callbacks[i];
            if (sc->executeFunction<bool>(cb.script, cb.function.c_str(), event->args.c_str(), &list))
            {
                va_end(list);
                return true;
            }
        }
    }

    va_end(list);

    return false;
}

}