/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Esteban Tovagliari, Cedric Paille, Kevin Dietrich
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "abc_nurbs.h"

#include "abc_transform.h"
#include "abc_util.h"

extern "C" {
#include "MEM_guardedalloc.h"

#include "DNA_curve_types.h"
#include "DNA_object_types.h"

#include "BLI_listbase.h"
#include "BLI_math.h"
#include "BLI_string.h"

#include "BKE_curve.h"
#include "BKE_object.h"
}

using Alembic::AbcGeom::bool_t;
using Alembic::AbcGeom::FloatArraySample;
using Alembic::AbcGeom::FloatArraySamplePtr;
using Alembic::AbcGeom::MetaData;
using Alembic::AbcGeom::P3fArraySamplePtr;
using Alembic::AbcGeom::kWrapExisting;

using Alembic::AbcGeom::IBoolProperty;
using Alembic::AbcGeom::ICompoundProperty;
using Alembic::AbcGeom::INuPatch;
using Alembic::AbcGeom::INuPatchSchema;
using Alembic::AbcGeom::IObject;
using Alembic::AbcGeom::ISampleSelector;

using Alembic::AbcGeom::OBoolProperty;
using Alembic::AbcGeom::OCompoundProperty;
using Alembic::AbcGeom::ONuPatch;
using Alembic::AbcGeom::ONuPatchSchema;

/* ************************************************************************** */

AbcNurbsWriter::AbcNurbsWriter(Scene *scene,
                               Object *ob,
                               AbcTransformWriter *parent,
                               uint32_t time_sampling,
                               ExportSettings &settings)
    : AbcObjectWriter(scene, ob, time_sampling, settings, parent)
{
	m_is_animated = isAnimated();

	/* if the object is static, use the default static time sampling */
	if (!m_is_animated) {
		m_time_sampling = 0;
	}

	Curve *curve = static_cast<Curve *>(m_object->data);
	size_t numNurbs = BLI_listbase_count(&curve->nurb);

	for (size_t i = 0; i < numNurbs; ++i) {
		std::stringstream str;
		str << m_name << '_' << i;

		while (parent->alembicXform().getChildHeader(str.str())) {
			str << "_";
		}

		ONuPatch nurbs(parent->alembicXform(), str.str().c_str(), m_time_sampling);
		m_nurbs_schema.push_back(nurbs.getSchema());
	}
}

bool AbcNurbsWriter::isAnimated() const
{
	/* check if object has shape keys */
	Curve *cu = static_cast<Curve *>(m_object->data);
	return (cu->key != NULL);
}

static void get_knots(std::vector<float> &knots, const int num_knots, float *nu_knots)
{
	if (num_knots <= 1) {
		return;
	}

	/* Add an extra knot at the beggining and end of the array since most apps
	 * require/expect them. */
	knots.reserve(num_knots + 2);

	knots.push_back(0.0f);

	for (int i = 0; i < num_knots; ++i) {
		knots.push_back(nu_knots[i]);
	}

	knots[0] = 2.0f * knots[1] - knots[2];
	knots.push_back(2.0f * knots[num_knots] - knots[num_knots - 1]);
}

void AbcNurbsWriter::do_write()
{
	/* we have already stored a sample for this object. */
	if (!m_first_frame && !m_is_animated) {
		return;
	}

	if (!ELEM(m_object->type, OB_SURF, OB_CURVE)) {
		return;
	}

	Curve *curve = static_cast<Curve *>(m_object->data);
	ListBase *nulb;

	if (m_object->curve_cache->deformed_nurbs.first != NULL) {
		nulb = &m_object->curve_cache->deformed_nurbs;
	}
	else {
		nulb = BKE_curve_nurbs_get(curve);
	}

	size_t count = 0;
	for (Nurb *nu = static_cast<Nurb *>(nulb->first); nu; nu = nu->next, ++count) {
		std::vector<float> knotsU;
		get_knots(knotsU, KNOTSU(nu), nu->knotsu);

		std::vector<float> knotsV;
		get_knots(knotsV, KNOTSV(nu), nu->knotsv);

		const int size = nu->pntsu * nu->pntsv;
		std::vector<Imath::V3f> positions(size);
		std::vector<float> weights(size);

		const BPoint *bp = nu->bp;

		for (int i = 0; i < size; ++i, ++bp) {
			copy_yup_from_zup(positions[i].getValue(), bp->vec);
			weights[i] = bp->vec[3];
		}

		ONuPatchSchema::Sample sample;
		sample.setUOrder(nu->orderu + 1);
		sample.setVOrder(nu->orderv + 1);
		sample.setPositions(positions);
		sample.setPositionWeights(weights);
		sample.setUKnot(FloatArraySample(knotsU));
		sample.setVKnot(FloatArraySample(knotsV));
		sample.setNu(nu->pntsu);
		sample.setNv(nu->pntsv);

		/* TODO(kevin): to accomodate other software we should duplicate control
		 * points to indicate that a NURBS is cyclic. */
		OCompoundProperty user_props = m_nurbs_schema[count].getUserProperties();

		if ((nu->flagu & CU_NURB_ENDPOINT) != 0) {
			OBoolProperty prop(user_props, "endpoint_u");
			prop.set(true);
		}

		if ((nu->flagv & CU_NURB_ENDPOINT) != 0) {
			OBoolProperty prop(user_props, "endpoint_v");
			prop.set(true);
		}

		if ((nu->flagu & CU_NURB_CYCLIC) != 0) {
			OBoolProperty prop(user_props, "cyclic_u");
			prop.set(true);
		}

		if ((nu->flagv & CU_NURB_CYCLIC) != 0) {
			OBoolProperty prop(user_props, "cyclic_v");
			prop.set(true);
		}

		m_nurbs_schema[count].set(sample);
	}
}

/* ************************************************************************** */

AbcNurbsReader::AbcNurbsReader(const IObject &object, ImportSettings &settings)
    : AbcObjectReader(object, settings)
{
	getNurbsPatches(m_iobject);
	get_min_max_time(m_iobject, m_schemas[0].first, m_min_time, m_max_time);
}

bool AbcNurbsReader::valid() const
{
	if (m_schemas.empty()) {
		return false;
	}

	std::vector< std::pair<INuPatchSchema, IObject> >::const_iterator it;
	for (it = m_schemas.begin(); it != m_schemas.end(); ++it) {
		const INuPatchSchema &schema = it->first;

		if (!schema.valid()) {
			return false;
		}
	}

	return true;
}

static bool set_knots(const FloatArraySamplePtr &knots, float *&nu_knots)
{
	if (!knots || knots->size() == 0) {
		return false;
	}

	/* Skip first and last knots, as they are used for padding. */
	const size_t num_knots = knots->size() - 2;
	nu_knots = static_cast<float *>(MEM_callocN(num_knots * sizeof(float), "abc_setsplineknotsu"));

	for (size_t i = 0; i < num_knots; ++i) {
		nu_knots[i] = (*knots)[i + 1];
	}

	return true;
}

void AbcNurbsReader::readObjectData(Main *bmain, const Alembic::Abc::ISampleSelector &sample_sel)
{
	Curve *cu = static_cast<Curve *>(BKE_curve_add(bmain, "abc_curve", OB_SURF));
	cu->actvert = CU_ACT_NONE;

	std::vector< std::pair<INuPatchSchema, IObject> >::iterator it;

	for (it = m_schemas.begin(); it != m_schemas.end(); ++it) {
		Nurb *nu = static_cast<Nurb *>(MEM_callocN(sizeof(Nurb), "abc_getnurb"));
		nu->flag  = CU_SMOOTH;
		nu->type = CU_NURBS;
		nu->resolu = cu->resolu;
		nu->resolv = cu->resolv;

		const INuPatchSchema &schema = it->first;
		const INuPatchSchema::Sample smp = schema.getValue(sample_sel);

		nu->orderu = smp.getUOrder() - 1;
		nu->orderv = smp.getVOrder() - 1;
		nu->pntsu = smp.getNumU();
		nu->pntsv = smp.getNumV();

		/* Read positions and weights. */

		const P3fArraySamplePtr positions = smp.getPositions();
		const FloatArraySamplePtr weights = smp.getPositionWeights();

		const size_t num_points = positions->size();

		nu->bp = static_cast<BPoint *>(MEM_callocN(num_points * sizeof(BPoint), "abc_setsplinetype"));

		BPoint *bp = nu->bp;
		float posw_in = 1.0f;

		for (int i = 0; i < num_points; ++i, ++bp) {
			const Imath::V3f &pos_in = (*positions)[i];

			if (weights) {
				posw_in = (*weights)[i];
			}

			copy_zup_from_yup(bp->vec, pos_in.getValue());
			bp->vec[3] = posw_in;
			bp->f1 = SELECT;
			bp->radius = 1.0f;
			bp->weight = 1.0f;
		}

		/* Read knots. */

		if (!set_knots(smp.getUKnot(), nu->knotsu)) {
			BKE_nurb_knot_calc_u(nu);
		}

		if (!set_knots(smp.getVKnot(), nu->knotsv)) {
			BKE_nurb_knot_calc_v(nu);
		}

		/* Read flags. */

		ICompoundProperty user_props = schema.getUserProperties();

		if (has_property(user_props, "enpoint_u")) {
			nu->flagu |= CU_NURB_ENDPOINT;
		}

		if (has_property(user_props, "enpoint_v")) {
			nu->flagv |= CU_NURB_ENDPOINT;
		}

		if (has_property(user_props, "cyclic_u")) {
			nu->flagu |= CU_NURB_CYCLIC;
		}

		if (has_property(user_props, "cyclic_v")) {
			nu->flagv |= CU_NURB_CYCLIC;
		}

		BLI_addtail(BKE_curve_nurbs_get(cu), nu);
	}

	BLI_strncpy(cu->id.name + 2, m_data_name.c_str(), m_data_name.size() + 1);

	m_object = BKE_object_add_only_object(bmain, OB_SURF, m_object_name.c_str());
	m_object->data = cu;
}

void AbcNurbsReader::getNurbsPatches(const IObject &obj)
{
	if (!obj.valid()) {
		return;
	}

	const int num_children = obj.getNumChildren();

	if (num_children == 0) {
		INuPatch abc_nurb(obj, kWrapExisting);
		INuPatchSchema schem = abc_nurb.getSchema();
		m_schemas.push_back(std::pair<INuPatchSchema, IObject>(schem, obj));
		return;
	}

	for (int i = 0; i < num_children; ++i) {
		bool ok = true;
		IObject child(obj, obj.getChildHeader(i).getName());

		if (!m_name.empty() && child.valid() && !begins_with(child.getFullName(), m_name)) {
			ok = false;
		}

		if (!child.valid()) {
			continue;
		}

		const MetaData &md = child.getMetaData();

		if (INuPatch::matches(md) && ok) {
			INuPatch abc_nurb(child, kWrapExisting);
			INuPatchSchema schem = abc_nurb.getSchema();
			m_schemas.push_back(std::pair<INuPatchSchema, IObject>(schem, child));
		}

		getNurbsPatches(child);
	}
}