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# This code originates from "Polyhedra Wireframe" feature of Alessandro
# Zomparelli's Tissue addon,
# https://github.com/alessandro-zomparelli/tissue/blob/master/polyhedra.py
# adapted to work as Sverchok's scripted node.

"""
in verts_in v
in edges_in s
in faces_in s
in thickness_in s
in subdivisions_in s
out verts_out v
out edges_out s
out faces_out s
"""

dissolve_inners = False

from math import pi, sin, cos

import bmesh
from mathutils import Vector

from sverchok.data_structure import zip_long_repeat
from sverchok.utils.sv_bmesh_utils import bmesh_from_pydata

def flatten_vector(vec, x, y):
    """
    Find planar vector according to two axis.
    :arg vec: Input vector.
    :type vec: :class:'mathutils.Vector'
    :arg x: First axis.
    :type x: :class:'mathutils.Vector'
    :arg y: Second axis.
    :type y: :class:'mathutils.Vector'
    :return: Projected 2D Vector.
    :rtype: :class:'mathutils.Vector'
    """
    vx = vec.project(x)
    vy = vec.project(y)
    mult = 1 if vx.dot(x) > 0 else -1
    vx = mult*vx.length
    mult = 1 if vy.dot(y) > 0 else -1
    vy = mult*vy.length
    return Vector((vx, vy))

def vector_rotation(vec):
    """
    Find vector rotation according to X axis.
    :arg vec: Input vector.
    :type vec: :class:'mathutils.Vector'
    :return: Angle in radians.
    :rtype: float
    """
    v0 = Vector((1,0))
    ang = Vector.angle_signed(vec, v0)
    if ang < 0: ang = 2*pi + ang
    return ang

verts_out = []
edges_out = []
faces_out = []
for verts, edges, faces, thickness, subdivisions in zip_long_repeat(verts_in, edges_in, faces_in, thickness_in, subdivisions_in):
    if isinstance(thickness, (list, tuple)):
        thickness = thickness[0]
    if isinstance(subdivisions, (list, tuple)):
        subdivisions = subdivisions[0]
    #faces = list(set([tuple(f) for f in faces]))
    uniq_faces = []
    for face in faces:
        if set(face) in [set(f) for f in uniq_faces]:
            pass
            #print(face)
        else:
            uniq_faces.append(face)
    bm = bmesh_from_pydata(verts, [], uniq_faces, normal_update=True)
    
    merge_dist = thickness*0.001

    subs = subdivisions

#    bm.verts.ensure_lookup_table()
#    bm.edges.ensure_lookup_table()
#    bm.faces.ensure_lookup_table()

    # Subdivide edges
    proportional_subs = True
    if subs > 1 and proportional_subs:
        wire_length = [e.calc_length() for e in bm.edges]
        all_edges = list(bm.edges)
        max_segment = max(wire_length)/subs
        split_edges = [[] for i in range(subs+1)]
        for e, l in zip(all_edges, wire_length):
            split_edges[int(l//max_segment)].append(e)
        for i in range(2,subs):
            perc = {}
            for e in split_edges[i]:
                perc[e]=0.1
            bmesh.ops.bisect_edges(bm, edges=split_edges[i], cuts=i, edge_percents=perc)

    ### Create double faces
    double_faces = []
    double_layer_edge = []
    double_layer_piece = []
    for f in bm.faces:
        verts0 = [v.co for v in f.verts]
        verts1 = [v.co for v in f.verts]
        verts1.reverse()
        double_faces.append(verts0)
        double_faces.append(verts1)

    # Create new bmesh object and data layers
    bm1 = bmesh.new()

    # Create faces and assign Edge Layers
    for verts in double_faces:
        new_verts = []
        for v in verts:
            vert = bm1.verts.new(v)
            new_verts.append(vert)
        bm1.faces.new(new_verts)

    bm1.verts.ensure_lookup_table()
    bm1.edges.ensure_lookup_table()
    bm1.faces.ensure_lookup_table()

    n_faces = len(bm.faces)
    n_doubles = len(bm1.faces)

    polyhedra = []

    for e in bm.edges:
        done = []

        # ERROR: Naked edges
        e_faces = len(e.link_faces)
        if e_faces < 2:
            bm.free()
            bm1.free()
            message = "Naked edges are not allowed"
            raise Exception(message)

        edge_vec =  e.verts[1].co - e.verts[0].co

        # run first face
        for i1 in range(e_faces-1):
            f1 = e.link_faces[i1]
            #edge_verts1 = [v.index for v in f1.verts if v in e.verts]
            verts1 = [v.index for v in f1.verts]
            va1 = verts1.index(e.verts[0].index)
            vb1 = verts1.index(e.verts[1].index)
            # chech if order of the edge matches the order of the face
            dir1 = va1 == (vb1+1)%len(verts1)
            edge_vec1 = edge_vec if dir1 else -edge_vec

            # run second face
            faces2 = []
            normals2 = []
            for i2 in range(i1+1,e_faces):
            #for i2 in range(n_faces):
                if i1 == i2: continue
                f2 = e.link_faces[i2]
                f2.normal_update()
                #edge_verts2 = [v.index for v in f2.verts if v in e.verts]
                verts2 = [v.index for v in f2.verts]
                va2 = verts2.index(e.verts[0].index)
                vb2 = verts2.index(e.verts[1].index)
                # chech if order of the edge matches the order of the face
                dir2 = va2 == (vb2+1)%len(verts2)
                # check for normal consistency
                if dir1 != dir2:
                    # add face
                    faces2.append(f2.index+1)
                    normals2.append(f2.normal)
                else:
                    # add flipped face
                    faces2.append(-(f2.index+1))
                    normals2.append(-f2.normal)

            # find first polyhedra (positive)
            plane_x = f1.normal                     # normal
            plane_y = plane_x.cross(edge_vec1).normalized()      # tangent face perp edge
            #print(f"PX: {plane_x.length}, PY: {plane_y.length}")
            id1 = (f1.index+1)

            min_angle0 = 10

            # check consistent faces
            if id1 not in done:
                id2 = None
                min_angle = min_angle0
                for i2, n2 in zip(faces2,normals2):
                    v2 = flatten_vector(-n2, plane_x, plane_y)
                    angle = vector_rotation(v2)
                    if angle < min_angle:
                        id2 = i2
                        min_angle = angle
                if id2 is None:
                    continue
                done.append(id2)
                add = True
                for p in polyhedra:
                    if id1 in p or id2 in p:
                        add = False
                        if id2 not in p:
                            p.append(id2)
                        if id1 not in p:
                            p.append(id1)
                        break
                if add:
                    polyhedra.append([id1, id2])

            # find second polyhedra (negative)
            plane_x = -f1.normal                    # normal
            plane_y = plane_x.cross(-edge_vec1)      # tangent face perp edge
            id1 = -(f1.index+1)

            if id1 not in done:
                id2 = None
                min_angle = min_angle0
                for i2, n2 in zip(faces2, normals2):
                    v2 = flatten_vector(n2, plane_x, plane_y)
                    angle = vector_rotation(v2)
                    if angle < min_angle:
                        id2 = -i2
                        min_angle = angle
                done.append(id2)
                add = True
                for p in polyhedra:
                    if id1 in p or id2 in p:
                        add = False
                        if id2 not in p: p.append(id2)
                        if id1 not in p: p.append(id1)
                        break
                if add: polyhedra.append([id1, id2])

    print("Polyhedra", polyhedra)
    for i in range(len(bm1.faces)):
        for j in (False,True):
            if j: id = i+1
            else: id = -(i+1)
            join = []
            keep = []
            for p in polyhedra:
                if id in p: join += p
                else: keep.append(p)
            if len(join) > 0:
                keep.append(list(dict.fromkeys(join)))
                polyhedra = keep

    for i, p in enumerate(polyhedra):
        for j in p:
            if j is None:
                continue
            bm1.faces[j].material_index = i

    delete_faces = []
    wireframe_faces = []
    not_wireframe_faces = []
    flat_faces = []

    bm.free()

    #bmesh.ops.bisect_edges(bm1, edges=bm1.edges, cuts=3)

    bm1.faces.index_update()
    #merge_verts = []
    for p in polyhedra:
        delete_faces_poly = []
        wireframe_faces_poly = []
        faces_id = [(f-1)*2 if f > 0 else (-f-1)*2+1 for f in p]
        faces_id_neg = [(-f-1)*2 if -f > 0 else (f-1)*2+1 for f in p]
        merge_verts = []
        faces = [bm1.faces[f_id] for f_id in faces_id]
        for f in faces:
            delete = False
            if f.index in delete_faces: continue
            
            cen = f.calc_center_median()
            for e in f.edges:
                mid = (e.verts[0].co + e.verts[1].co)/2
                vec1 = e.verts[0].co - e.verts[1].co
                vec2 = mid - cen
                ang = Vector.angle(vec1,vec2)
                length = vec2.length
                length = sin(ang)*length
                if length < thickness/2:
                    delete = True
            
            if False:
                sides = len(f.verts)
                for i in range(sides):
                    v = f.verts[i].co
                    v0 = f.verts[(i-1)%sides].co
                    v1 = f.verts[(i+1)%sides].co
                    vec0 = v0 - v
                    vec1 = v1 - v
                    ang = (pi - vec0.angle(vec1))/2
                    length = min(vec0.length, vec1.length)*sin(ang)
                    if length < thickness/2:
                        delete = True
                        break

            if delete:
                delete_faces_poly.append(f.index)
            else:
                wireframe_faces_poly.append(f.index)
            merge_verts += [v for v in f.verts]
        if len(wireframe_faces_poly) < 2:
            delete_faces += faces_id
            not_wireframe_faces += faces_id_neg
        else:
            wireframe_faces += wireframe_faces_poly
            flat_faces += delete_faces_poly

        #wireframe_faces = list(dict.fromkeys(wireframe_faces))
        bmesh.ops.remove_doubles(bm1, verts=merge_verts, dist=merge_dist)
        bm1.edges.ensure_lookup_table()
        bm1.faces.ensure_lookup_table()
        bm1.faces.index_update()


    wireframe_faces = [i for i in wireframe_faces if i not in not_wireframe_faces]
    wireframe_faces = list(dict.fromkeys(wireframe_faces))

    flat_faces = list(dict.fromkeys(flat_faces))

    ############# FRAME #############
    bm1.faces.index_update()
    wireframe_faces = [bm1.faces[i] for i in wireframe_faces]
    original_faces = wireframe_faces
    #bmesh.ops.remove_doubles(bm1, verts=merge_verts, dist=0.001)

    # detect edge loops

    loops = []
    boundaries_mat = []
    neigh_face_center = []
    face_normals = []

    # compute boundary frames
    new_faces = []
    wire_length = []
    vert_ids = []

    # append regular faces

    for f in original_faces:
        loop = list(f.verts)
        loops.append(loop)
        boundaries_mat.append([f.material_index for v in loop])
        f.normal_update()
        face_normals.append([f.normal for v in loop])

    push_verts = []
    inner_loops = []

    for loop_index, loop in enumerate(loops):
        is_boundary = loop_index < len(neigh_face_center)
        materials = boundaries_mat[loop_index]
        new_loop = []
        loop_ext = [loop[-1]] + loop + [loop[0]]

        # calc tangents
        tangents = []
        for i in range(len(loop)):
            # vertices
            vert0 = loop_ext[i]
            vert = loop_ext[i+1]
            vert1 = loop_ext[i+2]
            # edge vectors
            vec0 = (vert0.co - vert.co).normalized()
            vec1 = (vert.co - vert1.co).normalized()
            # tangent
            _vec1 = -vec1
            _vec0 = -vec0
            ang = (pi - vec0.angle(vec1))/2
            normal = face_normals[loop_index][i]
            tan0 = normal.cross(vec0)
            tan1 = normal.cross(vec1)
            tangent = (tan0 + tan1).normalized()/sin(ang)*thickness/2
            #if tangent.length > 0.04:
            #    print("T", tangent.length)
            tangents.append(tangent)

        # calc correct direction for boundaries
        mult = -1
        if is_boundary:
            dir_val = 0
            for i in range(len(loop)):
                surf_point = neigh_face_center[loop_index][i]
                tangent = tangents[i]
                vert = loop_ext[i+1]
                dir_val += tangent.dot(vert.co - surf_point)
            if dir_val > 0: mult = 1

        # add vertices
        for i in range(len(loop)):
            vert = loop_ext[i+1]
            area = 1
            new_co = vert.co + tangents[i] * mult * area
            # add vertex
            new_vert = bm1.verts.new(new_co)
            new_loop.append(new_vert)
            vert_ids.append(vert.index)
        new_loop.append(new_loop[0])

        # add faces
        #materials += [materials[0]]
        for i in range(len(loop)):
            v0 = loop_ext[i+1]
            v1 = loop_ext[i+2]
            v2 = new_loop[i+1]
            v3 = new_loop[i]
            face_verts = [v1,v0,v3,v2]
            if mult == -1: face_verts = [v0,v1,v2,v3]
            new_face = bm1.faces.new(face_verts)
            # Material by original edges
            piece_id = 0
            new_face.select = True
            new_faces.append(new_face)
            wire_length.append((v0.co - v1.co).length)
        max_segment = max(wire_length)/subdivisions
        #for f,l in zip(new_faces,wire_length):
        #    f.material_index = min(int(l/max_segment), subdivisions-1)
        bm1.verts.ensure_lookup_table()
        push_verts += [v.index for v in loop_ext]

    # At this point topology han been build, but not yet thickened

    bm1.verts.ensure_lookup_table()
    bm1.edges.ensure_lookup_table()
    bm1.faces.ensure_lookup_table()
    bm1.verts.index_update()

    ### Displace vertices ###

    circle_center = [0]*len(bm1.verts)
    circle_normal = [0]*len(bm1.verts)

    smooth_corners = [True] * len(bm1.verts)
    corners = [[] for i in range(len(bm1.verts))]
    normals = [0]*len(bm1.verts)
    vertices = [0]*len(bm1.verts)
    # Define vectors direction
    for f in new_faces:
        v0 = f.verts[0]
        v1 = f.verts[1]
        id = v0.index
        corners[id].append((v1.co - v0.co).normalized())
        normals[id] = v0.normal.copy()
        vertices[id] = v0
        smooth_corners[id] = False
    # Displace vertices
    for i, vecs in enumerate(corners):
        if len(vecs) > 0:
            v = vertices[i]
            nor = normals[i]
            ang = 0
            for vec in vecs:
                ang += nor.angle(vec)
            ang /= len(vecs)
            div = sin(ang)
            if div == 0: div = 1
            dv = nor*thickness/2/div
            #dv *= v.calc_shell_factor()
            if dv.length > 0.2:
                print(dv.length)
            v.co += dv

    # Removing original flat faces

    flat_faces = [bm1.faces[i] for i in flat_faces]
    for f in flat_faces:
        f.material_index = subdivisions+1
        for v in f.verts:
            if smooth_corners[v.index]:
                v.co += (1.0/v.calc_shell_factor()) * v.normal*thickness/2
                smooth_corners[v.index] = False
    delete_faces = delete_faces + [f.index for f in original_faces]
    delete_faces = list(dict.fromkeys(delete_faces))
    delete_faces = [bm1.faces[i] for i in delete_faces]
    bmesh.ops.delete(bm1, geom=delete_faces, context='FACES')

    bmesh.ops.remove_doubles(bm1, verts=bm1.verts, dist=merge_dist)
    bm1.faces.ensure_lookup_table()
    bm1.edges.ensure_lookup_table()
    bm1.verts.ensure_lookup_table()

    if dissolve_inners:
        bm1.edges.index_update()
        dissolve_edges = []
        for f in bm1.faces:
            e = f.edges[2]
            if e not in dissolve_edges:
                dissolve_edges.append(e)
        bmesh.ops.dissolve_edges(bm1, edges=dissolve_edges, use_verts=True, use_face_split=True)
    
    new_verts, new_edges, new_faces = pydata_from_bmesh(bm1)
    verts_out.append(new_verts)
    edges_out.append(new_edges)
    faces_out.append(new_faces)

