#  ***** BEGIN GPL LICENSE BLOCK *****
#
#   Copyright (C) 2021-2024 Robossembler LLC
#
#   Created by Ilia Kurochkin (brothermechanic)
#   contact:    brothermechanic@yandex.com
#
#   This file is part of Robossembler Framework
#   project repo:    https://gitlab.com/robossembler/framework
#
#   Robossembler Framework 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 3
#   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, see <https://www.gnu.org/licenses/>.
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#  ***** END GPL LICENSE BLOCK *****
#
# coding: utf-8
'''
DESCRIPTION.
Blender material generation functions.
'''

__version__ = '1.0'

import configparser
import logging
import os

import bpy
from bpy_extras.node_shader_utils import PrincipledBSDFWrapper

from .utils.shininess_to_roughness import shiny_to_rough

logger = logging.getLogger(__name__)


def black_material(obj):
    ''' Generate absolute black body shader '''
    mat_name = 'Robossembler_Black_Body'

    if mat_name in bpy.data.materials:
        # assign material to object
        if len(obj.material_slots) < 1:
            obj.data.materials.append(bpy.data.materials[mat_name])
        else:
            obj.material_slots[0].material = bpy.data.materials[mat_name]
    else:
        bmat = bpy.data.materials.new(name=mat_name)
        bmat.use_nodes = True
        bmat.diffuse_color = (0, 0, 0, 1)
        principled = bmat.node_tree.nodes['Principled BSDF']
        principled.inputs['Base Color'].default_value = (0, 0, 0, 1)
        principled.inputs['Specular IOR Level'].default_value = 0.0
        principled.inputs['Roughness'].default_value = 1.0
        # assign material to object
        if len(obj.material_slots) < 1:
            obj.data.materials.append(bmat)
        else:
            obj.material_slots[0].material = bmat

    logger.debug('Material was assigned to object: %s -> %s', bmat.name, obj.name)
    return bmat


def material_generator(obj, material_path):
    ''' Generate shader from FreeCAD's FEM material '''
    material = configparser.ConfigParser()
    with open(material_path, encoding='utf-8') as data:
        material.read_file(data)
    mat_name = os.path.splitext(os.path.basename(material_path))[0]
    if mat_name != material['General']['Name']:
        logger.warning(
            'Material %s is not supported! '
            'For Robossembler CG Pipeline material should have '
            'a same Name and FCMat filename!',
            mat_name)
        return black_material(obj)

    if mat_name in bpy.data.materials:
        # assign material to object
        if len(obj.material_slots) < 1:
            obj.data.materials.append(bpy.data.materials[mat_name])
        else:
            obj.material_slots[0].material = bpy.data.materials[mat_name]

        logger.debug('Material was assigned to object: %s -> %s', mat_name, obj.name)
        return obj

    if 'Rendering' not in material:
        logger.warning(
            'Material %s is not supported! '
            'For Robossembler CG Pipeline material should have '
            'Rendering category with shading parameters!',
            mat_name)
        return black_material(obj)

    rendering = material['Rendering']

    if rendering.get('DiffuseColor'):
        d_col_str = rendering['DiffuseColor']
        d_col4 = tuple(map(float, d_col_str[1:-1].split(', ')))
        d_col = d_col4[:-1]
    else:
        logger.warning(
            'DiffuseColor not found for %s %s.', mat_name, obj.name)
        d_col = (1.0, 0.0, 0.0)
    if rendering.get('Father'):
        if rendering['Father'] == 'Metal':
            me = 1
        else:
            me = 0
    else:
        me = 0
    if rendering.get('Shininess'):
        shiny = float(rendering['Shininess'])
        if shiny == 0:
            rg = 0.5
        else:
            rg = shiny_to_rough(shiny)
    else:
        rg = 0.5
    if rendering.get('EmissiveColor'):
        e_col_str = rendering['EmissiveColor']
        e_col4 = tuple(map(float, e_col_str[1:-1].split(', ')))
        e_col = e_col4[:-1]
    else:
        e_col = (0.0, 0.0, 0.0)
    if rendering.get('Transparency'):
        tr_str = rendering['Transparency']
        alpha = 1.0 - float(tr_str)
    else:
        alpha = 1.0

    bmat = bpy.data.materials.new(name=mat_name)
    bmat.use_nodes = True
    principled = PrincipledBSDFWrapper(bmat, is_readonly=False)
    principled.base_color = d_col
    principled.metallic = me
    principled.roughness = rg
    principled.emission_color = e_col
    principled.alpha = alpha
    bevel = bmat.node_tree.nodes.new(type="ShaderNodeBevel")
    bevel.location = -300, -300
    bevel.samples = 32
    bevel.inputs[0].default_value = 0.001
    principled_node = bmat.node_tree.nodes["Principled BSDF"]
    bmat.node_tree.links.new(bevel.outputs['Normal'], principled_node.inputs['Normal'])
    # assign material to object
    if len(obj.material_slots) < 1:
        obj.data.materials.append(bmat)
    else:
        obj.material_slots[0].material = bmat

    logger.debug('Material was assigned to object: %s -> %s', bmat.name, obj.name)
    return bmat