# ##### 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.
#
# ##### END GPL LICENSE BLOCK #####

import bpy
import bmesh

from sverchok.node_tree import SverchCustomTreeNode
from sverchok.utils.sv_bmesh_utils import bmesh_from_pydata


class VectorNormalNode(bpy.types.Node, SverchCustomTreeNode):
    ''' Find Vector's normals '''
    bl_idname = 'VectorNormalNode'
    bl_label = 'Vertex Normal'
    bl_icon = 'OUTLINER_OB_EMPTY'
    sv_icon = 'SV_VERTEX_NORMALS'

    def sv_init(self, context):
        self.inputs.new('SvVerticesSocket', "Vertices")
        self.inputs.new('SvStringsSocket', "Polygons")
        self.outputs.new('SvVerticesSocket', "Normals")

    def process(self):
        vers = self.inputs['Vertices'].sv_get()
        pols = self.inputs['Polygons'].sv_get()

        normalsFORout = []
        for i, obj in enumerate(vers):
            bm = bmesh_from_pydata(obj, [], pols[i], normal_update=True)
            normalsFORout.append([v.normal[:] for v in bm.verts])
            bm.free()

        self.outputs['Normals'].sv_set(normalsFORout)


def register():
    bpy.utils.register_class(VectorNormalNode)


def unregister():
    bpy.utils.unregister_class(VectorNormalNode)
