/**
 *  @file
 *  @author     2016 Stefan Radomski (stefan.radomski@cs.tu-darmstadt.de)
 *  @copyright  Simplified BSD
 *
 *  @cond
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the FreeBSD license as published by the FreeBSD
 *  project.
 *
 *  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.
 *
 *  You should have received a copy of the FreeBSD license along with this
 *  program. If not, see <http://www.opensource.org/licenses/bsd-license>.
 *  @endcond
 */

#ifndef INTERPRETERIMPL_H_29D5BEBA
#define INTERPRETERIMPL_H_29D5BEBA

#include <memory>
#include <mutex>
#include <list>
#include <map>
#include <string>

#include "uscxml/Common.h"
#include "uscxml/util/URL.h"
#include "uscxml/plugins/Factory.h"
#include "uscxml/plugins/DataModel.h"
#include "uscxml/interpreter/MicroStepImpl.h"
#include "uscxml/interpreter/ContentExecutorImpl.h"
#include "uscxml/interpreter/EventQueueImpl.h"
#include "uscxml/util/DOM.h"
#include <xercesc/dom/DOM.hpp>

namespace uscxml {

class InterpreterMonitor;
class InterpreterIssue;

class USCXML_API ActionLanguage {
public:
	MicroStep microStepper;
	DataModel dataModel;
	ContentExecutor execContent;
};

class USCXML_API InterpreterImpl :
	public MicroStepCallbacks,
	public DataModelCallbacks,
	public ContentExecutorCallbacks,
	public DelayedEventQueueCallbacks
//    public std::enable_shared_from_this<InterpreterImpl>
{
public:
	enum Binding {
		EARLY = 0,
		LATE = 1
	};

	InterpreterImpl();
	virtual ~InterpreterImpl();

	void cloneFrom(InterpreterImpl* other);
	void cloneFrom(std::shared_ptr<InterpreterImpl> other);

	virtual InterpreterState step(bool blocking) {
		if (!_isInitialized) {
			init();
			_state = USCXML_INITIALIZED;
		} else {
			_state = _microStepper.step(blocking);
		}
		return _state;
	}

	virtual void reset() {///< Reset state machine
		_microStepper.reset();
		_isInitialized = false;
		_state = USCXML_INSTANTIATED;
//        _dataModel.reset();
//        _eventQueue.reset();
//        _contentExecutor.reset();
	}

	virtual void cancel(); ///< Cancel and finalize state machine

	InterpreterState getState() {
		return _state;
	}

	std::list<xercesc::DOMElement*> getConfiguration() {
		return _microStepper.getConfiguration();
	}

	void setMonitor(InterpreterMonitor* monitor) {
		_monitor = monitor;
	}

	/**
	 MicrostepCallbacks
	 */
	virtual Event dequeueInternal() {
		_currEvent = _internalQueue.dequeue(false);
		if (_currEvent)
			_dataModel.setEvent(_currEvent);
		return _currEvent;
	}
	virtual Event dequeueExternal(bool blocking);
	virtual bool isTrue(const std::string& expr);

	virtual void raiseDoneEvent(xercesc::DOMElement* state, xercesc::DOMElement* doneData) {
		_execContent.raiseDoneEvent(state, doneData);
	}

	virtual void process(xercesc::DOMElement* block) {
		_execContent.process(block, _xmlPrefix);
	}

	virtual bool isMatched(const Event& event, const std::string& eventDesc);
	virtual void initData(xercesc::DOMElement* element);

	virtual void invoke(xercesc::DOMElement* invoke) {
		_execContent.invoke(invoke);
	}

	virtual void uninvoke(xercesc::DOMElement* invoke) {
		_execContent.uninvoke(invoke);
	}

	virtual InterpreterMonitor* getMonitor() {
		return _monitor;
	}

	/**
	 DataModelCallbacks
	 */
	virtual const std::string& getName() {
		return _name;
	}
	virtual const std::string& getSessionId() {
		return _sessionId;
	}
	virtual const std::map<std::string, IOProcessor>& getIOProcessors() {
		return _ioProcs;
	}
	virtual const std::map<std::string, Invoker>& getInvokers() {
		return _invokers;
	}

	virtual bool isInState(const std::string& stateId) {
		return _microStepper.isInState(stateId);
	}
	virtual xercesc::DOMDocument* getDocument() const {
		return _document;
	}

	/**
	 ContentExecutorCallbacks
	 */

	virtual void enqueueInternal(const Event& event) {
		return _internalQueue.enqueue(event);
	}
	virtual void enqueueExternal(const Event& event) {
		return _externalQueue.enqueue(event);
	}
	virtual void enqueueExternalDelayed(const Event& event, size_t delayMs, const std::string& eventUUID) {
		return _delayQueue.enqueueDelayed(event, delayMs, eventUUID);
	}
	virtual void cancelDelayed(const std::string& eventId);

	virtual size_t getLength(const std::string& expr) {
		return _dataModel.getLength(expr);
	}

	virtual void setForeach(const std::string& item,
	                        const std::string& array,
	                        const std::string& index,
	                        uint32_t iteration) {
		return _dataModel.setForeach(item, array, index, iteration);
	}
	virtual Data evalAsData(const std::string& expr) {
		return _dataModel.evalAsData(expr);
	}

	virtual Data getAsData(const std::string& expr) {
		return _dataModel.getAsData(expr);
	}

	virtual void assign(const std::string& location, const Data& data);

	virtual std::string getInvokeId() {
		return _invokeId;
	}
	virtual std::string getBaseURL() {
		return _baseURL;
	}

	virtual bool checkValidSendType(const std::string& type, const std::string& target);
	virtual void invoke(const std::string& type, const std::string& src, bool autoForward, xercesc::DOMElement* finalize, const Event& invokeEvent);
	virtual void uninvoke(const std::string& invokeId);
	virtual void enqueue(const std::string& type, const std::string& target, size_t delayMs, const Event& sendEvent);

	virtual const Event& getCurrentEvent() {
		return _currEvent;
	}

	/**
	 DelayedEventQueueCallbacks
	 */

	virtual void eventReady(Event& event, const std::string& eventUUID);

	/** --- */

	void setActionLanguage(const ActionLanguage& al) {
		_execContent = al.execContent;
		_microStepper = al.microStepper;
		_dataModel = al.dataModel;
	}

	static std::map<std::string, std::weak_ptr<InterpreterImpl> > getInstances();

	virtual xercesc::DOMDocument* getDocument() {
		return _document;
	}

protected:
	static void addInstance(std::shared_ptr<InterpreterImpl> instance);

	Binding _binding;

	std::string _sessionId;
	std::string _name;
	std::string _invokeId; // TODO: Never set!

	bool _isInitialized;
	xercesc::DOMDocument* _document;
	xercesc::DOMElement* _scxml;

	std::map<std::string, std::tuple<std::string, std::string, std::string> > _delayedEventTargets;

	virtual void init();

	static std::map<std::string, std::weak_ptr<InterpreterImpl> > _instances;
	static std::recursive_mutex _instanceMutex;
	std::recursive_mutex _delayMutex;

	friend class Interpreter;
	friend class InterpreterIssue;
	friend class TransformerImpl;
	friend class USCXMLInvoker;
	friend class SCXMLIOProcessor;

	X _xmlPrefix;
	X _xmlNS;
	Factory* _factory;

	URL _baseURL;

	MicroStep _microStepper;
	DataModel _dataModel;
	ContentExecutor _execContent;

	InterpreterState _state;

	EventQueue _internalQueue;
	EventQueue _externalQueue;
	EventQueue _parentQueue;
	DelayedEventQueue _delayQueue;

	Event _currEvent;
	Event _invokeReq;

	std::map<std::string, IOProcessor> _ioProcs;
	std::map<std::string, Invoker> _invokers;
	std::set<std::string> _autoForwarders;
	InterpreterMonitor* _monitor;

private:
	void setupDOM();
};

}

#endif /* end of include guard: INTERPRETERIMPL_H_29D5BEBA */