/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/* 
 * File:   Stack.cpp
 * Author: jens
 * 
 * Created on 25. Oktober 2019, 18:26
 */
#include <cassert>
#include "Stack.hpp"

using namespace std;

Stack::Stack(const std::string &name)
: m_name(name)
, m_pLayers(nullptr)
{
}

Stack::Stack(const Stack& orig)
: m_name(orig.m_name)
, m_pLayers(orig.m_pLayers)
{
}

Stack::~Stack()
{ }

size_t Stack::numLayers()
{
	size_t count = 0;
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		count++;
		pLayer = pLayer->next;
	}
	return count;
}

void Stack::addLayer(Layer *pOtherLayer)
{
	if (!m_pLayers)
	{
		m_pLayers = pOtherLayer;
		pOtherLayer->prev = nullptr;
	}
	else
	{
		Layer *pLayer = m_pLayers;
		while(pLayer->next) 
		{
			pLayer = pLayer->next;
		}
		pLayer->next = pOtherLayer;
		pOtherLayer->prev = pLayer;
	}
}

Layer* Stack::getLayer(size_t layerId) const
{
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		if (pLayer->id() == layerId)
		{
			return pLayer;
		}
		pLayer = pLayer->next;
	}
	return nullptr;
	
}

bool Stack::load(LayerConstructor *pLayerConstructor)
{
	std::cout << "Importing Project " << m_name << std::endl;
	ifstream ifs(m_name + string(".prj"));
	
	Json::Reader reader;
	Json::Value project;
	reader.parse(ifs, project);
	
	const string &name = project["stack"]["name"].asString();
	Json::Value &layers = project["stack"]["layers"];
			
	for (int i=0; i < layers.size(); i++)
	{
		Json::Value &layer = layers[i];
		
		string layername = layer["name"].asString();
		int numVisibleX = layer["numVisibleX"].asInt();
		int numVisibleY = layer["numVisibleY"].asInt();
		int numHidden = layer["numHidden"].asInt();
		
		Layer *pLayer = nullptr;
		if (!pLayerConstructor)
		{
			pLayer = new Layer(layername, i, numVisibleX, numVisibleY, numHidden);
		}
		else
		{
			pLayer = pLayerConstructor->onConstruct(layername, i, numVisibleX, numVisibleY, numHidden);
		}
		
		assert(pLayer != nullptr);
		
		pLayer->fromJson(layer["rbm"]);
		addLayer(pLayer);
	}
	
	return true;
}

bool Stack::save()
{
	std::cout << "Exporting Project " << m_name << std::endl;
	ofstream ofs(m_name + string(".prj"));
	
	Json::StyledWriter writer;
	Json::Value project;
	project["stack"]["name"] = m_name;
	
	Json::Value layers(Json::arrayValue);
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		layers.append(pLayer->toJson());
		pLayer = pLayer->next;
	}
	project["stack"]["layers"] = layers;
	
	ofs << writer.write(project);
	
	return true;
}

void Stack::weightsInit(double stddev)
{
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		pLayer->weightsInit(stddev);
		pLayer = pLayer->next;
	}
}

bool Stack::loadWeights()
{
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		if (!pLayer->loadWeights(m_name))
		{
			return false;
		}
		pLayer = pLayer->next;
	}
	return true;
}

bool Stack::saveWeights()
{
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		if (!pLayer->saveWeights(m_name))
		{
			return false;
		}
		pLayer = pLayer->next;
	}
	return true;
}

void Stack::train(const arma::mat& batch, Rbm::IListener* pListener)
{
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		train(pLayer->id(), batch, pListener);
		pLayer = pLayer->next;
	}
}

void Stack::train(size_t layerId, const arma::mat& batch, Rbm::IListener* pListener)
{
	arma::mat thisBatch = batch;
	Layer *pLayer = m_pLayers;
	while(pLayer)
	{
		if (pLayer->id() == layerId)
		{
			break;
		}
		thisBatch = pLayer->toHiddenProbs(thisBatch);
		pLayer = pLayer->next;
	}
	
	if (pLayer)
	{
		std::cout << m_name << ": " << " Training of layer " << std::to_string(layerId) << std::endl;
		pLayer->train(thisBatch, pListener);
	}
}