/*
 * ***** 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.
 *
 * The Original Code is Copyright (C) Blender Foundation
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 * CSG operations. 
 */

/** \file blender/modifiers/intern/MOD_boolean_util.c
 *  \ingroup modifiers
 */


#include "DNA_material_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "BLI_listbase.h"
#include "BLI_ghash.h"

#include "BKE_cdderivedmesh.h"
#include "BKE_depsgraph.h"
#include "BKE_global.h"
#include "BKE_material.h"
#include "BKE_mesh.h"
#include "BKE_object.h"

#include "CSG_BooleanOps.h"

#include "MOD_boolean_util.h"

/**
 * Here's the vertex iterator structure used to walk through
 * the blender vertex structure.
 */

typedef struct {
	DerivedMesh *dm;
	Object *ob;
	int pos;
} VertexIt;

/**
 * Implementations of local vertex iterator functions.
 * These describe a blender mesh to the CSG module.
 */

static void VertexIt_Destruct(CSG_VertexIteratorDescriptor *iterator)
{
	if (iterator->it) {
		/* deallocate memory for iterator */
		MEM_freeN(iterator->it);
		iterator->it = NULL;
	}
	iterator->Done = NULL;
	iterator->Fill = NULL;
	iterator->Reset = NULL;
	iterator->Step = NULL;
	iterator->num_elements = 0;

}		

static int VertexIt_Done(CSG_IteratorPtr it)
{
	VertexIt *iterator = (VertexIt *)it;
	return(iterator->pos >= iterator->dm->getNumVerts(iterator->dm));
}

static void VertexIt_Fill(CSG_IteratorPtr it, CSG_IVertex *vert)
{
	VertexIt *iterator = (VertexIt *)it;
	MVert *verts = iterator->dm->getVertArray(iterator->dm);

	float global_pos[3];

	/* boolean happens in global space, transform both with obmat */
	mul_v3_m4v3(
	    global_pos,
	    iterator->ob->obmat,
	    verts[iterator->pos].co
	    );

	vert->position[0] = global_pos[0];
	vert->position[1] = global_pos[1];
	vert->position[2] = global_pos[2];
}

static void VertexIt_Step(CSG_IteratorPtr it)
{
	VertexIt *iterator = (VertexIt *)it;
	iterator->pos++;
} 
 
static void VertexIt_Reset(CSG_IteratorPtr it)
{
	VertexIt *iterator = (VertexIt *)it;
	iterator->pos = 0;
}

static void VertexIt_Construct(CSG_VertexIteratorDescriptor *output, DerivedMesh *dm, Object *ob)
{

	VertexIt *it;
	if (output == NULL) return;

	/* allocate some memory for blender iterator */
	it = (VertexIt *)(MEM_mallocN(sizeof(VertexIt), "Boolean_VIt"));
	if (it == NULL) {
		return;
	}
	/* assign blender specific variables */
	it->dm = dm;
	it->ob = ob; /* needed for obmat transformations */

	it->pos = 0;

	/* assign iterator function pointers. */
	output->Step = VertexIt_Step;
	output->Fill = VertexIt_Fill;
	output->Done = VertexIt_Done;
	output->Reset = VertexIt_Reset;
	output->num_elements = it->dm->getNumVerts(it->dm);
	output->it = it;
}

/**
 * Blender Face iterator
 */

typedef struct {
	DerivedMesh *dm;
	int pos;
	int offset;
	int flip;
} FaceIt;

static void FaceIt_Destruct(CSG_FaceIteratorDescriptor *iterator)
{
	MEM_freeN(iterator->it);
	iterator->Done = NULL;
	iterator->Fill = NULL;
	iterator->Reset = NULL;
	iterator->Step = NULL;
	iterator->num_elements = 0;
}

static int FaceIt_Done(CSG_IteratorPtr it)
{
	/* assume CSG_IteratorPtr is of the correct type. */
	FaceIt *iterator = (FaceIt *)it;
	return(iterator->pos >= iterator->dm->getNumTessFaces(iterator->dm));
}

static void FaceIt_Fill(CSG_IteratorPtr it, CSG_IFace *face)
{
	/* assume CSG_IteratorPtr is of the correct type. */
	FaceIt *face_it = (FaceIt *)it;
	MFace *mfaces = face_it->dm->getTessFaceArray(face_it->dm);
	MFace *mface = &mfaces[face_it->pos];

	/* reverse face vertices if necessary */
	face->vertex_index[1] = mface->v2;
	if (face_it->flip == 0) {
		face->vertex_index[0] = mface->v1;
		face->vertex_index[2] = mface->v3;
	}
	else {
		face->vertex_index[2] = mface->v1;
		face->vertex_index[0] = mface->v3;
	}
	if (mface->v4) {
		face->vertex_index[3] = mface->v4;
		face->vertex_number = 4;
	}
	else {
		face->vertex_number = 3;
	}

	face->orig_face = face_it->offset + face_it->pos;
}

static void FaceIt_Step(CSG_IteratorPtr it)
{
	FaceIt *face_it = (FaceIt *)it;
	face_it->pos++;
}

static void FaceIt_Reset(CSG_IteratorPtr it)
{
	FaceIt *face_it = (FaceIt *)it;
	face_it->pos = 0;
}	

static void FaceIt_Construct(
        CSG_FaceIteratorDescriptor *output, DerivedMesh *dm, int offset, Object *ob)
{
	FaceIt *it;
	if (output == NULL) return;

	/* allocate some memory for blender iterator */
	it = (FaceIt *)(MEM_mallocN(sizeof(FaceIt), "Boolean_FIt"));
	if (it == NULL) {
		return;
	}
	/* assign blender specific variables */
	it->dm = dm;
	it->offset = offset;
	it->pos = 0;

	/* determine if we will need to reverse order of face vertices */
	if (ob->size[0] < 0.0f) {
		if (ob->size[1] < 0.0f && ob->size[2] < 0.0f) {
			it->flip = 1;
		}
		else if (ob->size[1] >= 0.0f && ob->size[2] >= 0.0f) {
			it->flip = 1;
		}
		else {
			it->flip = 0;
		}
	}
	else {
		if (ob->size[1] < 0.0f && ob->size[2] < 0.0f) {
			it->flip = 0;
		}
		else if (ob->size[1] >= 0.0f && ob->size[2] >= 0.0f) {
			it->flip = 0;
		}
		else {
			it->flip = 1;
		}
	}

	/* assign iterator function pointers. */
	output->Step = FaceIt_Step;
	output->Fill = FaceIt_Fill;
	output->Done = FaceIt_Done;
	output->Reset = FaceIt_Reset;
	output->num_elements = it->dm->getNumTessFaces(it->dm);
	output->it = it;
}

static Object *AddNewBlenderMesh(Scene *scene, Base *base)
{
	/* This little function adds a new mesh object to the blender object list
	 * It uses ob to duplicate data as this seems to be easier than creating
	 * a new one. This new oject contains no faces nor vertices. */
	Mesh *old_me;
	Base *basen;
	Object *ob_new;

	/* now create a new blender object.
	 * duplicating all the settings from the previous object
	 * to the new one. */
	ob_new = BKE_object_copy(base->object);

	/* Ok we don't want to use the actual data from the
	 * last object, the above function incremented the
	 * number of users, so decrement it here. */
	old_me = ob_new->data;
	old_me->id.us--;

	/* Now create a new base to add into the linked list of
	 * vase objects. */

	basen = MEM_mallocN(sizeof(Base), "duplibase");
	*basen = *base;
	BLI_addhead(&scene->base, basen);   /* addhead: anders oneindige lus */
	basen->object = ob_new;
	basen->flag &= ~SELECT;
				
	/* Initialize the mesh data associated with this object. */
	ob_new->data = BKE_mesh_add(G.main, "Mesh");

	/* Finally assign the object type. */
	ob_new->type = OB_MESH;

	return ob_new;
}

static void InterpCSGFace(
        DerivedMesh *dm, DerivedMesh *orig_dm, int index, int orig_index, int nr,
        float mapmat[4][4])
{
	float obco[3], *co[4], *orig_co[4], w[4][4];
	MFace *mface, *orig_mface;
	int j;

	mface = CDDM_get_tessface(dm, index);
	orig_mface = orig_dm->getTessFaceArray(orig_dm) + orig_index;

	/* get the vertex coordinates from the original mesh */
	orig_co[0] = (orig_dm->getVertArray(orig_dm) + orig_mface->v1)->co;
	orig_co[1] = (orig_dm->getVertArray(orig_dm) + orig_mface->v2)->co;
	orig_co[2] = (orig_dm->getVertArray(orig_dm) + orig_mface->v3)->co;
	orig_co[3] = (orig_mface->v4) ? (orig_dm->getVertArray(orig_dm) + orig_mface->v4)->co : NULL;

	/* get the vertex coordinates from the new derivedmesh */
	co[0] = CDDM_get_vert(dm, mface->v1)->co;
	co[1] = CDDM_get_vert(dm, mface->v2)->co;
	co[2] = CDDM_get_vert(dm, mface->v3)->co;
	co[3] = (nr == 4) ? CDDM_get_vert(dm, mface->v4)->co : NULL;

	for (j = 0; j < nr; j++) {
		/* get coordinate into the space of the original mesh */
		if (mapmat)
			mul_v3_m4v3(obco, mapmat, co[j]);
		else
			copy_v3_v3(obco, co[j]);

		interp_weights_face_v3(w[j], orig_co[0], orig_co[1], orig_co[2], orig_co[3], obco);
	}

	CustomData_interp(&orig_dm->faceData, &dm->faceData, &orig_index, NULL, (float *)w, 1, index);
}

/* Iterate over the CSG Output Descriptors and create a new DerivedMesh
 * from them */
static DerivedMesh *ConvertCSGDescriptorsToDerivedMesh(
        CSG_FaceIteratorDescriptor *face_it,
        CSG_VertexIteratorDescriptor *vertex_it,
        float parinv[4][4],
        float mapmat[4][4],
        Material **mat,
        int *totmat,
        DerivedMesh *dm1,
        Object *ob1,
        DerivedMesh *dm2,
        Object *ob2)
{
	DerivedMesh *result, *orig_dm;
	GHash *material_hash = NULL;
	Mesh *me1 = (Mesh *)ob1->data;
	Mesh *me2 = (Mesh *)ob2->data;
	int i, *origindex_layer;

	/* create a new DerivedMesh */
	result = CDDM_new(vertex_it->num_elements, 0, face_it->num_elements, 0, 0);
	CustomData_merge(&dm1->faceData, &result->faceData, CD_MASK_DERIVEDMESH & ~(CD_MASK_NORMAL | CD_MASK_ORIGINDEX),
	                 CD_DEFAULT, face_it->num_elements);
	CustomData_merge(&dm2->faceData, &result->faceData, CD_MASK_DERIVEDMESH & ~(CD_MASK_NORMAL | CD_MASK_ORIGINDEX),
	                 CD_DEFAULT, face_it->num_elements);

	/* step through the vertex iterators: */
	for (i = 0; !vertex_it->Done(vertex_it->it); i++) {
		CSG_IVertex csgvert;
		MVert *mvert = CDDM_get_vert(result, i);

		/* retrieve a csg vertex from the boolean module */
		vertex_it->Fill(vertex_it->it, &csgvert);
		vertex_it->Step(vertex_it->it);

		/* we have to map the vertex coordinates back in the coordinate frame
		 * of the resulting object, since it was computed in world space */
		mul_v3_m4v3(mvert->co, parinv, csgvert.position);
	}

	/* a hash table to remap materials to indices */
	material_hash = BLI_ghash_ptr_new("CSG_mat gh");

	if (mat)
		*totmat = 0;

	origindex_layer = result->getTessFaceDataArray(result, CD_ORIGINDEX);

	/* step through the face iterators */
	for (i = 0; !face_it->Done(face_it->it); i++) {
		Mesh *orig_me;
		Object *orig_ob;
		Material *orig_mat;
		CSG_IFace csgface;
		MFace *mface;
		int orig_index, mat_nr;

		/* retrieve a csg face from the boolean module */
		face_it->Fill(face_it->it, &csgface);
		face_it->Step(face_it->it);

		/* find the original mesh and data */
		orig_ob = (csgface.orig_face < dm1->getNumTessFaces(dm1)) ? ob1 : ob2;
		orig_dm = (csgface.orig_face < dm1->getNumTessFaces(dm1)) ? dm1 : dm2;
		orig_me = (orig_ob == ob1) ? me1 : me2;
		orig_index = (orig_ob == ob1) ? csgface.orig_face : csgface.orig_face - dm1->getNumTessFaces(dm1);

		/* copy all face layers, including mface */
		CustomData_copy_data(&orig_dm->faceData, &result->faceData, orig_index, i, 1);

		/* set mface */
		mface = CDDM_get_tessface(result, i);
		mface->v1 = csgface.vertex_index[0];
		mface->v2 = csgface.vertex_index[1];
		mface->v3 = csgface.vertex_index[2];
		mface->v4 = (csgface.vertex_number == 4) ? csgface.vertex_index[3] : 0;

		/* set material, based on lookup in hash table */
		orig_mat = give_current_material(orig_ob, mface->mat_nr + 1);

		if (mat && orig_mat) {
			if (!BLI_ghash_haskey(material_hash, orig_mat)) {
				mat[*totmat] = orig_mat;
				mat_nr = mface->mat_nr = (*totmat)++;
				BLI_ghash_insert(material_hash, orig_mat, SET_INT_IN_POINTER(mat_nr));
			}
			else
				mface->mat_nr = GET_INT_FROM_POINTER(BLI_ghash_lookup(material_hash, orig_mat));
		}
		else if (orig_mat) {
			if (orig_ob == ob1) {
				/* No need to change materian index for faces from left operand */
			}
			else {
				/* for faces from right operand checn if there's needed material in left operand and if it is,
				 * use index of that material, otherwise fallback to first material (material with index=0) */
				if (!BLI_ghash_haskey(material_hash, orig_mat)) {
					int a;

					mat_nr = 0;
					for (a = 0; a < ob1->totcol; a++) {
						if (give_current_material(ob1, a + 1) == orig_mat) {
							mat_nr = a;
							break;
						}
					}

					BLI_ghash_insert(material_hash, orig_mat, SET_INT_IN_POINTER(mat_nr));

					mface->mat_nr = mat_nr;
				}
				else
					mface->mat_nr = GET_INT_FROM_POINTER(BLI_ghash_lookup(material_hash, orig_mat));
			}
		}
		else
			mface->mat_nr = 0;

		InterpCSGFace(result, orig_dm, i, orig_index, csgface.vertex_number,
		              (orig_me == me2) ? mapmat : NULL);

		test_index_face(mface, &result->faceData, i, csgface.vertex_number);

		if (origindex_layer && orig_ob == ob2)
			origindex_layer[i] = ORIGINDEX_NONE;
	}

	if (material_hash)
		BLI_ghash_free(material_hash, NULL, NULL);

	CDDM_calc_edges_tessface(result);

	CDDM_tessfaces_to_faces(result); /*builds ngon faces from tess (mface) faces*/

	/* this fixes shading issues but SHOULD NOT.
	 * TODO, find out why face normals are wrong & flicker - campbell */
#if 0
	DM_debug_print(result);

	CustomData_free(&result->faceData, result->numTessFaceData);
	result->numTessFaceData = 0;
	DM_ensure_tessface(result);
#endif

	CDDM_calc_normals(result);

	return result;
}
	
static void BuildMeshDescriptors(
        struct DerivedMesh *dm,
        struct Object *ob,
        int face_offset,
        struct CSG_FaceIteratorDescriptor *face_it,
        struct CSG_VertexIteratorDescriptor *vertex_it)
{
	VertexIt_Construct(vertex_it, dm, ob);
	FaceIt_Construct(face_it, dm, face_offset, ob);
}
	
static void FreeMeshDescriptors(
        struct CSG_FaceIteratorDescriptor *face_it,
        struct CSG_VertexIteratorDescriptor *vertex_it)
{
	VertexIt_Destruct(vertex_it);
	FaceIt_Destruct(face_it);
}

static DerivedMesh *NewBooleanDerivedMesh_intern(
        DerivedMesh *dm, struct Object *ob, DerivedMesh *dm_select, struct Object *ob_select,
        int int_op_type, Material **mat, int *totmat)
{

	float inv_mat[4][4];
	float map_mat[4][4];

	DerivedMesh *result = NULL;

	if (dm == NULL || dm_select == NULL) return 0;
	if (!dm->getNumTessFaces(dm) || !dm_select->getNumTessFaces(dm_select)) return 0;

	/* we map the final object back into ob's local coordinate space. For this
	 * we need to compute the inverse transform from global to ob (inv_mat),
	 * and the transform from ob to ob_select for use in interpolation (map_mat) */
	invert_m4_m4(inv_mat, ob->obmat);
	mult_m4_m4m4(map_mat, inv_mat, ob_select->obmat);
	invert_m4_m4(inv_mat, ob_select->obmat);

	{
		/* interface with the boolean module:
		 *
		 * the idea is, we pass the boolean module verts and faces using the
		 * provided descriptors. once the boolean operation is performed, we
		 * get back output descriptors, from which we then build a DerivedMesh */

		CSG_VertexIteratorDescriptor vd_1, vd_2;
		CSG_FaceIteratorDescriptor fd_1, fd_2;
		CSG_OperationType op_type;
		CSG_BooleanOperation *bool_op;

		/* work out the operation they chose and pick the appropriate
		 * enum from the csg module. */
		switch (int_op_type) {
			case 1: op_type = e_csg_intersection; break;
			case 2: op_type = e_csg_union; break;
			case 3: op_type = e_csg_difference; break;
			case 4: op_type = e_csg_classify; break;
			default: op_type = e_csg_intersection;
		}

		BuildMeshDescriptors(dm_select, ob_select, 0, &fd_1, &vd_1);
		BuildMeshDescriptors(dm, ob, dm_select->getNumTessFaces(dm_select), &fd_2, &vd_2);

		bool_op = CSG_NewBooleanFunction();

		/* perform the operation */
		if (CSG_PerformBooleanOperation(bool_op, op_type, fd_1, vd_1, fd_2, vd_2)) {
			CSG_VertexIteratorDescriptor vd_o;
			CSG_FaceIteratorDescriptor fd_o;

			CSG_OutputFaceDescriptor(bool_op, &fd_o);
			CSG_OutputVertexDescriptor(bool_op, &vd_o);

			/* iterate through results of operation and insert
			 * into new object */
			result = ConvertCSGDescriptorsToDerivedMesh(
			    &fd_o, &vd_o, inv_mat, map_mat, mat, totmat, dm_select, ob_select, dm, ob);

			/* free up the memory */
			CSG_FreeVertexDescriptor(&vd_o);
			CSG_FreeFaceDescriptor(&fd_o);
		}
		else
			printf("Unknown internal error in boolean\n");

		CSG_FreeBooleanOperation(bool_op);

		FreeMeshDescriptors(&fd_1, &vd_1);
		FreeMeshDescriptors(&fd_2, &vd_2);
	}

	return result;
}

int NewBooleanMesh(Scene *scene, Base *base, Base *base_select, int int_op_type)
{
	Mesh *me_new;
	int a, maxmat, totmat = 0;
	Object *ob_new, *ob, *ob_select;
	Material **mat;
	DerivedMesh *result;
	DerivedMesh *dm_select;
	DerivedMesh *dm;

	ob = base->object;
	ob_select = base_select->object;

	dm = mesh_get_derived_final(scene, ob, CD_MASK_BAREMESH);
	dm_select = mesh_create_derived_view(scene, ob_select, 0); // no modifiers in editmode ??

	maxmat = ob->totcol + ob_select->totcol;
	mat = (Material **)MEM_mallocN(sizeof(Material *) * maxmat, "NewBooleanMeshMat");
	
	/* put some checks in for nice user feedback */
	if (dm == NULL || dm_select == NULL) {
		return 0;
	}

	if (!dm->getNumTessFaces(dm) || !dm_select->getNumTessFaces(dm_select)) {
		MEM_freeN(mat);
		return -1;
	}
	
	result = NewBooleanDerivedMesh_intern(dm, ob, dm_select, ob_select, int_op_type, mat, &totmat);

	if (result == NULL) {
		MEM_freeN(mat);
		return 0;
	}

	/* create a new blender mesh object - using 'base' as  a template */
	ob_new = AddNewBlenderMesh(scene, base_select);
	me_new = ob_new->data;

	DM_to_mesh(result, me_new, ob_new);
	result->release(result);

	dm->release(dm);
	dm_select->release(dm_select);

	/* add materials to object */
	for (a = 0; a < totmat; a++)
		assign_material(ob_new, mat[a], a + 1, BKE_MAT_ASSIGN_USERPREF);

	MEM_freeN(mat);

	/* update dag */
	DAG_id_tag_update(&ob_new->id, OB_RECALC_DATA);

	return 1;
}

DerivedMesh *NewBooleanDerivedMesh(DerivedMesh *dm, struct Object *ob, DerivedMesh *dm_select, struct Object *ob_select,
                                   int int_op_type)
{
	return NewBooleanDerivedMesh_intern(dm, ob, dm_select, ob_select, int_op_type, NULL, NULL);
}