// TnzCore includes
#include "tstream.h"

// TnzExt includes
#include "ext/plasticskeletondeformation.h"

// STL includes
#include <set>

// tcg includes
#include "tcg/tcg_misc.h"
#include "tcg/tcg_pool.h"
#include "tcg/tcg_function_types.h"
#include "tcg/tcg_iterator_ops.h"

#include "ext/plasticskeleton.h"

PERSIST_IDENTIFIER(PlasticSkeletonVertex, "PlasticSkeletonVertex")
PERSIST_IDENTIFIER(PlasticSkeleton, "PlasticSkeleton")

DEFINE_CLASS_CODE(PlasticSkeleton, 122)

//************************************************************************************
//    PlasticSkeletonVertex  implementation
//************************************************************************************

PlasticSkeletonVertex::PlasticSkeletonVertex()
	: tcg::Vertex<TPointD>(), m_number(-1), m_parent(-1), m_minAngle(-(std::numeric_limits<double>::max)()), m_maxAngle((std::numeric_limits<double>::max)()), m_interpolate(true)
{
}

//-------------------------------------------------------------------------------

PlasticSkeletonVertex::PlasticSkeletonVertex(const TPointD &pos)
	: tcg::Vertex<TPointD>(pos), m_number(-1), m_parent(-1), m_minAngle(-(std::numeric_limits<double>::max)()), m_maxAngle((std::numeric_limits<double>::max)()), m_interpolate(true)
{
}

//-------------------------------------------------------------------------------

PlasticSkeletonVertex::operator PlasticHandle() const
{
	PlasticHandle result(P());
	result.m_interpolate = m_interpolate;
	return result;
}

//-------------------------------------------------------------------------------

void PlasticSkeletonVertex::saveData(TOStream &os)
{
	os.child("name") << m_name;
	os.child("number") << m_number;
	os.child("pos") << this->P().x << this->P().y;
	os.child("interpolate") << (int)this->m_interpolate;

	if (m_minAngle != -(std::numeric_limits<double>::max)())
		os.child("minAngle") << m_minAngle;

	if (m_maxAngle != (std::numeric_limits<double>::max)())
		os.child("maxAngle") << m_maxAngle;
}

//-------------------------------------------------------------------------------

void PlasticSkeletonVertex::loadData(TIStream &is)
{
	int val;

	std::string tagName;
	while (is.openChild(tagName)) {
		if (tagName == "name")
			is >> m_name, is.matchEndTag();
		else if (tagName == "number")
			is >> m_number, is.matchEndTag();
		else if (tagName == "pos")
			is >> this->P().x >> this->P().y, is.matchEndTag();
		else if (tagName == "interpolate")
			is >> val, m_interpolate = (bool)val, is.matchEndTag();
		else if (tagName == "minAngle")
			is >> m_minAngle, is.matchEndTag();
		else if (tagName == "maxAngle")
			is >> m_maxAngle, is.matchEndTag();
		else
			is.skipCurrentTag();
	}
}

//************************************************************************************
//    PlasticSkeleton::Imp  definition
//************************************************************************************

class PlasticSkeleton::Imp
{
public:
	std::set<PlasticSkeletonDeformation *> m_deformations; //!< Registered deformations for this skeleton (not owned)
	tcg::indices_pool<int> m_numbersPool;				   //!< Vertex numbers pool (used for naming vertices only)

public:
	Imp() {}
	Imp(const Imp &other);
	Imp &operator=(const Imp &other);

	Imp(Imp &&other);
	Imp &operator=(Imp &&other);
};

//===============================================================================

PlasticSkeleton::Imp::Imp(const Imp &other)
	: m_numbersPool(other.m_numbersPool)
{
}

//-------------------------------------------------------------------------------

PlasticSkeleton::Imp &PlasticSkeleton::Imp::operator=(const Imp &other)
{
	m_numbersPool = other.m_numbersPool;
	return *this;
}

//-------------------------------------------------------------------------------
PlasticSkeleton::Imp::Imp(Imp &&other)
	: m_numbersPool(std::move(other.m_numbersPool))
{
}

//-------------------------------------------------------------------------------

PlasticSkeleton::Imp &PlasticSkeleton::Imp::operator=(Imp &&other)
{
	m_numbersPool = std::move(other.m_numbersPool);
	return *this;
}

//************************************************************************************
//    PlasticSkeleton  implementation
//************************************************************************************

PlasticSkeleton::PlasticSkeleton()
	: m_imp(new Imp)
{
}

//------------------------------------------------------------------

PlasticSkeleton::~PlasticSkeleton()
{
}

//------------------------------------------------------------------

PlasticSkeleton::PlasticSkeleton(const PlasticSkeleton &other)
	: mesh_type(other), m_imp(new Imp(*other.m_imp))
{
}

//------------------------------------------------------------------

PlasticSkeleton &PlasticSkeleton::operator=(const PlasticSkeleton &other)
{
	assert(m_imp->m_deformations.empty());

	mesh_type::operator=(other);
	*m_imp = *other.m_imp;

	return *this;
}

//------------------------------------------------------------------
PlasticSkeleton::PlasticSkeleton(PlasticSkeleton &&other)
	: mesh_type(std::forward<mesh_type>(other)), m_imp(new Imp(std::move(*other.m_imp)))
{
}

//------------------------------------------------------------------

PlasticSkeleton &PlasticSkeleton::operator=(PlasticSkeleton &&other)
{
	assert(m_imp->m_deformations.empty());

	mesh_type::operator=(std::forward<mesh_type>(other));
	*m_imp = std::move(*other.m_imp);

	return *this;
}

//------------------------------------------------------------------

void PlasticSkeleton::addListener(PlasticSkeletonDeformation *deformation)
{
	m_imp->m_deformations.insert(deformation);
}

//------------------------------------------------------------------

void PlasticSkeleton::removeListener(PlasticSkeletonDeformation *deformation)
{
	m_imp->m_deformations.erase(deformation);
}

//------------------------------------------------------------------

bool PlasticSkeleton::setVertexName(int v, const QString &newName)
{
	assert(!newName.isEmpty());

	if (m_vertices[v].m_name == newName)
		return true;

	// Traverse the vertices list - if the same name already exists, return false
	tcg::list<vertex_type>::iterator vt, vEnd(m_vertices.end());
	for (vt = m_vertices.begin(); vt != vEnd; ++vt)
		if (vt.m_idx != v && vt->m_name == newName) // v should be skipped in the check
			return false;

	// Notify deformations before changing the name
	std::set<PlasticSkeletonDeformation *>::iterator dt, dEnd(m_imp->m_deformations.end());
	for (dt = m_imp->m_deformations.begin(); dt != dEnd; ++dt)
		(*dt)->vertexNameChange(this, v, newName);

	m_vertices[v].m_name = newName;

	return true;
}

//------------------------------------------------------------------

void PlasticSkeleton::moveVertex(int v, const TPointD &pos)
{
	mesh_type::vertex(v).P() = pos; // Apply new position
}

//------------------------------------------------------------------

int PlasticSkeleton::addVertex(const PlasticSkeletonVertex &vx, int parent)
{
	// Add the vertex
	int v = mesh_type::addVertex(vx);

	// Retrieve a vertex index
	PlasticSkeletonVertex &vx_ = vertex(v);

	vx_.m_number = m_imp->m_numbersPool.acquire();

	// Assign a name to the vertex in case none was given
	QString name(vx.name());
	if (name.isEmpty())
		name = (v == 0) ? QString("Root") : "Vertex " + QString::number(vx_.m_number).rightJustified(3, '_');

	// Ensure the name is unique
	while (!setVertexName(v, name))
		name += "_";

	if (parent >= 0) {
		// Link it to the parent
		mesh_type::addEdge(edge_type(parent, v)); // Observe that parent is always v0
		vx_.m_parent = parent;
		assert(parent != v);
	}

	// Notify deformations
	std::set<PlasticSkeletonDeformation *>::iterator dt, dEnd(m_imp->m_deformations.end());
	for (dt = m_imp->m_deformations.begin(); dt != dEnd; ++dt)
		(*dt)->addVertex(this, v);

	return v;
}

//-------------------------------------------------------------------------------

int PlasticSkeleton::insertVertex(const PlasticSkeletonVertex &vx,
								  int parent, const std::vector<int> &children)
{
	assert(parent >= 0);

	if (children.empty())
		return addVertex(vx, parent);

	// Add the vertex
	int v = mesh_type::addVertex(vx);

	// Retrieve a vertex index
	PlasticSkeletonVertex &vx_ = vertex(v);

	vx_.m_number = m_imp->m_numbersPool.acquire();

	// Assign a name to the vertex in case none was given
	QString name(vx.name());
	if (name.isEmpty())
		name = "Vertex " + QString::number(vx_.m_number).rightJustified(3, '_');

	// Ensure the name is unique
	while (!setVertexName(v, name))
		name += "_";

	// Link it to the parent
	{
		PlasticSkeletonVertex &vx_ = vertex(v);

		mesh_type::addEdge(edge_type(parent, v)); // Observe that parent is always v0
		vx_.m_parent = parent;
		assert(parent != v);
	}

	// Link it to children
	int c, cCount = int(children.size());
	for (c = 0; c != cCount; ++c) {
		int vChild = children[c];
		PlasticSkeletonVertex &vxChild = vertex(vChild);

		assert(vxChild.parent() == parent);

		// Remove the edge and substitute it with a new one
		int e = edgeInciding(parent, vChild);
		mesh_type::removeEdge(e);

		mesh_type::addEdge(edge_type(v, vChild));
		vxChild.m_parent = v;
		assert(v != vChild);
	}

	// Notify deformations
	std::set<PlasticSkeletonDeformation *>::iterator dt, dEnd(m_imp->m_deformations.end());
	for (dt = m_imp->m_deformations.begin(); dt != dEnd; ++dt)
		(*dt)->insertVertex(this, v);

	return v;
}

//-------------------------------------------------------------------------------

int PlasticSkeleton::insertVertex(const PlasticSkeletonVertex &vx, int e)
{
	const edge_type &ed = edge(e);
	return insertVertex(vx, ed.vertex(0), std::vector<int>(1, ed.vertex(1)));
}

//-------------------------------------------------------------------------------

void PlasticSkeleton::removeVertex(int v)
{
	int vNumber;
	{
		// Reparent all of v's children to its parent's children, first. This is needed
		// to ensure that deformations update vertex deformations correctly.

		PlasticSkeletonVertex vx(vertex(v)); // Note the COPY - not referencing. It's best since
											 // we'll be iterating and erasing vx's edges at the same time
		int parent = vx.m_parent;
		if (parent < 0) {
			// Root case - clear the whole skeleton
			clear(); // Should ensure that the next inserted vertex has index 0
			return;
		}

		// Add edges from parent to vx's children
		vertex_type::edges_iterator et, eEnd = vx.edgesEnd();
		for (et = vx.edgesBegin(); et != eEnd; ++et) {
			int vChild = edge(*et).vertex(1);
			if (vChild == v)
				continue;

			mesh_type::removeEdge(*et);

			mesh_type::addEdge(edge_type(parent, vChild));
			vertex(vChild).m_parent = parent;
			assert(vChild != parent);
		}

		vNumber = vx.m_number;
	}

	// Notify deformations BEFORE removing the vertex, so the vertex deformations are still accessible.
	std::set<PlasticSkeletonDeformation *>::iterator dt, dEnd(m_imp->m_deformations.end());
	for (dt = m_imp->m_deformations.begin(); dt != dEnd; ++dt)
		(*dt)->deleteVertex(this, v);

	// Then, erase v. This already ensures that edges connected with v are destroyed.
	mesh_type::removeVertex(v);

	m_imp->m_numbersPool.release(vNumber);
}

//-------------------------------------------------------------------------------

void PlasticSkeleton::clear()
{
	mesh_type::clear();
	m_imp->m_numbersPool.clear();

	// Notify deformations
	std::set<PlasticSkeletonDeformation *>::iterator dt, dEnd(m_imp->m_deformations.end());
	for (dt = m_imp->m_deformations.begin(); dt != dEnd; ++dt)
		(*dt)->clear(this);
}

//-------------------------------------------------------------------------------

void PlasticSkeleton::squeeze()
{
	// Squeeze associated deformations first
	int v, e;

	// Update indices
	tcg::list<vertex_type>::iterator vt, vEnd(m_vertices.end());
	for (v = 0, vt = m_vertices.begin(); vt != vEnd; ++vt, ++v)
		vt->setIndex(v);

	tcg::list<edge_type>::iterator et, eEnd(m_edges.end());
	for (e = 0, et = m_edges.begin(); et != eEnd; ++et, ++e)
		et->setIndex(e);

	// Update stored indices
	for (et = m_edges.begin(); et != eEnd; ++et) {
		edge_type &ed = *et;
		ed.setVertex(0, vertex(ed.vertex(0)).getIndex());
		ed.setVertex(1, vertex(ed.vertex(1)).getIndex());
	}

	for (vt = m_vertices.begin(); vt != vEnd; ++vt) {
		vertex_type &vx = *vt;

		if (vt->m_parent >= 0)
			vt->m_parent = vertex(vt->m_parent).getIndex();

		vertex_type::edges_iterator vet, veEnd(vx.edgesEnd());
		for (vet = vx.edgesBegin(); vet != veEnd; ++vet)
			*vet = edge(*vet).getIndex();
	}

	// Finally, rebuild the actual containers
	if (!m_edges.empty()) {
		tcg::list<edge_type> temp(m_edges.begin(), m_edges.end());
		std::swap(m_edges, temp);
	}

	if (!m_vertices.empty()) {
		tcg::list<vertex_type> temp(m_vertices.begin(), m_vertices.end());
		std::swap(m_vertices, temp);
	}
}

//-------------------------------------------------------------------------------

void PlasticSkeleton::saveData(TOStream &os)
{
	// NOTE: Primitives saved by INDEX iteration is NOT COINCIDENTAL - since
	// the lists' internal linking could have been altered to mismatch the
	// natural indexing referred to by primitives' data.

	if (m_vertices.size() != m_vertices.nodesCount() ||
		m_edges.size() != m_edges.nodesCount()) {
		// Ensure that there are no holes in the representation
		PlasticSkeleton skel(*this);

		skel.squeeze();
		skel.saveData(os);

		return;
	}

	// Save vertices
	os.openChild("V");
	{
		int vCount = int(m_vertices.size());
		os << vCount;

		for (int v = 0; v != vCount; ++v)
			os.child("Vertex") << m_vertices[v];
	}
	os.closeChild();

	// Save edges
	os.openChild("E");
	{
		int eCount = int(m_edges.size());
		os << eCount;

		for (int e = 0; e != eCount; ++e) {
			PlasticSkeleton::edge_type &ed = m_edges[e];
			os << ed.vertex(0) << ed.vertex(1);
		}
	}
	os.closeChild();
}

//-------------------------------------------------------------------------------

void PlasticSkeleton::loadData(TIStream &is)
{
	// Ensure the skeleton is clean
	clear();

	// Load vertices
	std::string str;
	int i, size;

	while (is.openChild(str)) {
		if (str == "V") {
			is >> size;

			std::vector<int> acquiredVertexNumbers;
			acquiredVertexNumbers.reserve(size);

			m_vertices.reserve(size);

			for (i = 0; i < size; ++i) {
				if (is.openChild(str) && (str == "Vertex")) {
					vertex_type vx;

					is >> vx;
					int idx = mesh_type::addVertex(vx);

					if (vx.m_number < 0)
						vertex(idx).m_number = vx.m_number = idx + 1;

					acquiredVertexNumbers.push_back(vx.m_number);

					is.matchEndTag();
				} else
					assert(false), is.skipCurrentTag();
			}

			m_imp->m_numbersPool = tcg::indices_pool<int>(
				acquiredVertexNumbers.begin(), acquiredVertexNumbers.end());

			is.matchEndTag();
		} else if (str == "E") {
			is >> size;

			m_edges.reserve(size);
			int v0, v1;

			for (i = 0; i < size; ++i) {
				is >> v0 >> v1;

				addEdge(edge_type(v0, v1));
				vertex(v1).m_parent = v0;
			}

			is.matchEndTag();
		} else
			assert(false), is.skipCurrentTag();
	}
}

//************************************************************************************
//    PlasticSkeleton  utility functions
//************************************************************************************

int PlasticSkeleton::closestVertex(const TPointD &pos, double *dist) const
{
	// Traverse vertices
	double d2, minDist2 = (std::numeric_limits<double>::max)();
	int v = -1;

	tcg::list<vertex_type>::const_iterator vt, vEnd(m_vertices.end());
	for (vt = m_vertices.begin(); vt != vEnd; ++vt) {
		d2 = tcg::point_ops::dist2(pos, vt->P());
		if (d2 < minDist2)
			minDist2 = d2, v = int(vt.m_idx);
	}

	if (dist && v >= 0)
		*dist = sqrt(minDist2);

	return v;
}

//-------------------------------------------------------------------------------

int PlasticSkeleton::closestEdge(const TPointD &pos, double *dist) const
{
	// Traverse edges
	double d, minDist = (std::numeric_limits<double>::max)();
	int e = -1;

	tcg::list<edge_type>::const_iterator et, eEnd(m_edges.end());
	for (et = m_edges.begin(); et != eEnd; ++et) {
		const TPointD &vp0 = vertex(et->vertex(0)).P(), &vp1 = vertex(et->vertex(1)).P();

		d = tcg::point_ops::segDist(vp0, vp1, pos);
		if (d < minDist)
			minDist = d, e = int(et.m_idx);
	}

	if (dist && e >= 0)
		*dist = minDist;

	return e;
}

//-------------------------------------------------------------------------------

std::vector<PlasticHandle> PlasticSkeleton::verticesToHandles() const
{
	// Someway, PlasticHandle's EXPLICIT unary constructors are not enough
	// to disambiguate the direct construction of a vector of PlasticHandles
	// from m_vertices, at least with *gcc*. I guess it could be a compiler bug.

	// So, we'll convert them using an explicit casting iterator...

	typedef tcg::function < PlasticHandle (PlasticSkeletonVertex::*)() const,
		&PlasticSkeletonVertex::operator PlasticHandle> Func;

	return std::vector<PlasticHandle>(
		tcg::make_cast_it(m_vertices.begin(), Func()),
		tcg::make_cast_it(m_vertices.end(), Func()));
}