node_wrangler.py

        elif merge_hide == 'NON_SHADER':
            do_hide = True

        tree_type = context.space_data.node_tree.type
        if tree_type == 'GEOMETRY':
            node_type = 'GeometryNode'
        if tree_type == 'COMPOSITING':
            node_type = 'CompositorNode'
        elif tree_type == 'SHADER':
            node_type = 'ShaderNode'
        elif tree_type == 'TEXTURE':
            node_type = 'TextureNode'
        nodes, links = get_nodes_links(context)
        mode = self.mode
        merge_type = self.merge_type
        # Prevent trying to add Z-Combine in not 'COMPOSITING' node tree.
        # 'ZCOMBINE' works only if mode == 'MIX'
        # Setting mode to None prevents trying to add 'ZCOMBINE' node.
        if (merge_type == 'ZCOMBINE' or merge_type == 'ALPHAOVER') and tree_type != 'COMPOSITING':
            merge_type = 'MIX'
            mode = 'MIX'
        if (merge_type != 'MATH' and merge_type != 'GEOMETRY') and tree_type == 'GEOMETRY':
            merge_type = 'AUTO'
        # The MixRGB node and math nodes used for geometry nodes are of type 'ShaderNode'
        if (merge_type == 'MATH' or merge_type == 'MIX') and tree_type == 'GEOMETRY':
            node_type = 'ShaderNode'
        selected_mix = []  # entry = [index, loc]
        selected_shader = []  # entry = [index, loc]
        selected_geometry = [] # entry = [index, loc]
        selected_math = []  # entry = [index, loc]
        selected_vector = [] # entry = [index, loc]
        selected_z = []  # entry = [index, loc]
        selected_alphaover = []  # entry = [index, loc]

        for i, node in enumerate(nodes):
            if node.select and node.outputs:
                if merge_type == 'AUTO':
                    for (type, types_list, dst) in (
                            ('SHADER', ('MIX', 'ADD'), selected_shader),
                            ('GEOMETRY', [t[0] for t in geo_combine_operations], selected_geometry),
                            ('RGBA', [t[0] for t in blend_types], selected_mix),
                            ('VALUE', [t[0] for t in operations], selected_math),
                            ('VECTOR', [], selected_vector),
                    ):
                        output = get_first_enabled_output(node)
                        output_type = output.type
                        valid_mode = mode in types_list
                        # When mode is 'MIX' we have to cheat since the mix node is not used in
                        # geometry nodes.
                        if tree_type == 'GEOMETRY':
                            if mode == 'MIX':
                                if output_type == 'VALUE' and type == 'VALUE':
                                    valid_mode = True
                                elif output_type == 'VECTOR' and type == 'VECTOR':
                                    valid_mode = True
                                elif type == 'GEOMETRY':
                                    valid_mode = True
                        # When mode is 'MIX' use mix node for both 'RGBA' and 'VALUE' output types.
                        # Cheat that output type is 'RGBA',
                        # and that 'MIX' exists in math operations list.
                        # This way when selected_mix list is analyzed:
                        # Node data will be appended even though it doesn't meet requirements.
                        elif output_type != 'SHADER' and mode == 'MIX':
                            output_type = 'RGBA'
                            valid_mode = True
                        if output_type == type and valid_mode:
                            dst.append([i, node.location.x, node.location.y, node.dimensions.x, node.hide])
                else:
                    for (type, types_list, dst) in (
                            ('SHADER', ('MIX', 'ADD'), selected_shader),
                            ('GEOMETRY', [t[0] for t in geo_combine_operations], selected_geometry),
                            ('MIX', [t[0] for t in blend_types], selected_mix),
                            ('MATH', [t[0] for t in operations], selected_math),
                            ('ZCOMBINE', ('MIX', ), selected_z),
                            ('ALPHAOVER', ('MIX', ), selected_alphaover),
                    ):
                        if merge_type == type and mode in types_list:
                            dst.append([i, node.location.x, node.location.y, node.dimensions.x, node.hide])
        # When nodes with output kinds 'RGBA' and 'VALUE' are selected at the same time
        # use only 'Mix' nodes for merging.
        # For that we add selected_math list to selected_mix list and clear selected_math.
        if selected_mix and selected_math and merge_type == 'AUTO':
            selected_mix += selected_math
            selected_math = []
        for nodes_list in [selected_mix, selected_shader, selected_geometry, selected_math, selected_vector, selected_z, selected_alphaover]:
            if not nodes_list:
                continue
            count_before = len(nodes)
            # sort list by loc_x - reversed
            nodes_list.sort(key=lambda k: k[1], reverse=True)
            # get maximum loc_x
            loc_x = nodes_list[0][1] + nodes_list[0][3] + 70
            nodes_list.sort(key=lambda k: k[2], reverse=True)

            # Change the node type for math nodes in a geometry node tree.
            if tree_type == 'GEOMETRY':
                if nodes_list is selected_math or nodes_list is selected_vector or nodes_list is selected_mix:
                    node_type = 'ShaderNode'
                    if mode == 'MIX':
                        mode = 'ADD'
                else:
                    node_type = 'GeometryNode'
            if merge_position == 'CENTER':
                loc_y = ((nodes_list[len(nodes_list) - 1][2]) + (nodes_list[len(nodes_list) - 2][2])) / 2  # average yloc of last two nodes (lowest two)
                if nodes_list[len(nodes_list) - 1][-1] == True:  # if last node is hidden, mix should be shifted up a bit
                    if do_hide:
                        loc_y += 40
                    else:
                        loc_y += 80
            else:
                loc_y = nodes_list[len(nodes_list) - 1][2]
            offset_y = 100
            if not do_hide:
                offset_y = 200
            if nodes_list == selected_shader and not do_hide_shader:
                offset_y = 150.0
            the_range = len(nodes_list) - 1
            if len(nodes_list) == 1:
                the_range = 1
            was_multi = False
            for i in range(the_range):
                if nodes_list == selected_mix:
                    add_type = node_type + 'MixRGB'
                    add = nodes.new(add_type)
                    add.blend_type = mode
                    if mode != 'MIX':
                        add.inputs[0].default_value = 1.0
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 1
                    second = 2
                    add.width_hidden = 100.0
                elif nodes_list == selected_math:
                    add_type = node_type + 'Math'
                    add = nodes.new(add_type)
                    add.operation = mode
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 1
                    add.width_hidden = 100.0
                elif nodes_list == selected_shader:
                    if mode == 'MIX':
                        add_type = node_type + 'MixShader'
                        add = nodes.new(add_type)
                        add.hide = do_hide_shader
                        if do_hide_shader:
                            loc_y = loc_y - 50
                        first = 1
                        second = 2
                        add.width_hidden = 100.0
                    elif mode == 'ADD':
                        add_type = node_type + 'AddShader'
                        add = nodes.new(add_type)
                        add.hide = do_hide_shader
                        if do_hide_shader:
                            loc_y = loc_y - 50
                        first = 0
                        second = 1
                        add.width_hidden = 100.0
                elif nodes_list == selected_geometry:
                    if mode in ('JOIN', 'MIX'):
                        add_type = node_type + 'JoinGeometry'
                        add = self.merge_with_multi_input(nodes_list, merge_position, do_hide, loc_x, links, nodes, add_type,[0])
                    else:
                        add_type = node_type + 'Boolean'
                        indices = [0,1] if mode == 'DIFFERENCE' else [1]
                        add = self.merge_with_multi_input(nodes_list, merge_position, do_hide, loc_x, links, nodes, add_type,indices)
                        add.operation = mode
                    was_multi = True
                    break
                elif nodes_list == selected_vector:
                    add_type = node_type + 'VectorMath'
                    add = nodes.new(add_type)
                    add.operation = mode
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 1
                    add.width_hidden = 100.0
                elif nodes_list == selected_z:
                    add = nodes.new('CompositorNodeZcombine')
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 0
                    second = 2
                    add.width_hidden = 100.0
                elif nodes_list == selected_alphaover:
                    add = nodes.new('CompositorNodeAlphaOver')
                    add.show_preview = False
                    add.hide = do_hide
                    if do_hide:
                        loc_y = loc_y - 50
                    first = 1
                    second = 2
                    add.width_hidden = 100.0
                add.location = loc_x, loc_y
                loc_y += offset_y
                add.select = True

            # This has already been handled separately
            if was_multi:
                continue
            count_adds = i + 1
            count_after = len(nodes)
            index = count_after - 1
            first_selected = nodes[nodes_list[0][0]]
            # "last" node has been added as first, so its index is count_before.
            last_add = nodes[count_before]
            # Create list of invalid indexes.
            invalid_nodes = [nodes[n[0]] for n in (selected_mix + selected_math + selected_shader + selected_z + selected_geometry)]

            # Special case:
            # Two nodes were selected and first selected has no output links, second selected has output links.
            # Then add links from last add to all links 'to_socket' of out links of second selected.
            first_selected_output = get_first_enabled_output(first_selected)
            if len(nodes_list) == 2:
                if not first_selected_output.links:
                    second_selected = nodes[nodes_list[1][0]]
                    for ss_link in second_selected.outputs[0].links:
                        # Prevent cyclic dependencies when nodes to be merged are linked to one another.
                        # Link only if "to_node" index not in invalid indexes list.
                        if not self.link_creates_cycle(ss_link, invalid_nodes):
                            links.new(last_add.outputs[0], ss_link.to_socket)
            # add links from last_add to all links 'to_socket' of out links of first selected.
            for fs_link in first_selected_output.links:
                # Link only if "to_node" index not in invalid indexes list.
                if not self.link_creates_cycle(fs_link, invalid_nodes):
                    links.new(last_add.outputs[0], fs_link.to_socket)
            # add link from "first" selected and "first" add node
            node_to = nodes[count_after - 1]
            links.new(first_selected_output, node_to.inputs[first])
            if node_to.type == 'ZCOMBINE':
                for fs_out in first_selected.outputs:
                    if fs_out != first_selected_output and fs_out.name in ('Z', 'Depth'):
                        links.new(fs_out, node_to.inputs[1])
                        break
            # add links between added ADD nodes and between selected and ADD nodes
            for i in range(count_adds):
                if i < count_adds - 1:
                    node_from = nodes[index]
                    node_to = nodes[index - 1]
                    node_to_input_i = first
                    node_to_z_i = 1  # if z combine - link z to first z input
                    links.new(get_first_enabled_output(node_from), node_to.inputs[node_to_input_i])
                    if node_to.type == 'ZCOMBINE':
                        for from_out in node_from.outputs:
                            if from_out != get_first_enabled_output(node_from) and from_out.name in ('Z', 'Depth'):
                                links.new(from_out, node_to.inputs[node_to_z_i])
                if len(nodes_list) > 1:
                    node_from = nodes[nodes_list[i + 1][0]]
                    node_to = nodes[index]
                    node_to_input_i = second
                    node_to_z_i = 3  # if z combine - link z to second z input
                    links.new(get_first_enabled_output(node_from), node_to.inputs[node_to_input_i])
                    if node_to.type == 'ZCOMBINE':
                        for from_out in node_from.outputs:
                            if from_out != get_first_enabled_output(node_from) and from_out.name in ('Z', 'Depth'):
                                links.new(from_out, node_to.inputs[node_to_z_i])
                index -= 1
            # set "last" of added nodes as active
            nodes.active = last_add
            for i, x, y, dx, h in nodes_list:
                nodes[i].select = False

        return {'FINISHED'}


class NWBatchChangeNodes(Operator, NWBase):
    bl_idname = "node.nw_batch_change"
    bl_label = "Batch Change"
    bl_description = "Batch Change Blend Type and Math Operation"
    bl_options = {'REGISTER', 'UNDO'}

    blend_type: EnumProperty(
        name="Blend Type",
        items=blend_types + navs,
    )
    operation: EnumProperty(
        name="Operation",
        items=operations + navs,
    )

    def execute(self, context):
        blend_type = self.blend_type
        operation = self.operation
        for node in context.selected_nodes:
            if node.type == 'MIX_RGB' or node.bl_idname == 'GeometryNodeAttributeMix':
                if not blend_type in [nav[0] for nav in navs]:
                    node.blend_type = blend_type
                else:
                    if blend_type == 'NEXT':
                        index = [i for i, entry in enumerate(blend_types) if node.blend_type in entry][0]
                        #index = blend_types.index(node.blend_type)
                        if index == len(blend_types) - 1:
                            node.blend_type = blend_types[0][0]
                        else:
                            node.blend_type = blend_types[index + 1][0]

                    if blend_type == 'PREV':
                        index = [i for i, entry in enumerate(blend_types) if node.blend_type in entry][0]
                        if index == 0:
                            node.blend_type = blend_types[len(blend_types) - 1][0]
                        else:
                            node.blend_type = blend_types[index - 1][0]

            if node.type == 'MATH' or node.bl_idname == 'GeometryNodeAttributeMath':
                if not operation in [nav[0] for nav in navs]:
                    node.operation = operation
                else:
                    if operation == 'NEXT':
                        index = [i for i, entry in enumerate(operations) if node.operation in entry][0]
                        #index = operations.index(node.operation)
                        if index == len(operations) - 1:
                            node.operation = operations[0][0]
                        else:
                            node.operation = operations[index + 1][0]

                    if operation == 'PREV':
                        index = [i for i, entry in enumerate(operations) if node.operation in entry][0]
                        #index = operations.index(node.operation)
                        if index == 0:
                            node.operation = operations[len(operations) - 1][0]
                        else:
                            node.operation = operations[index - 1][0]

        return {'FINISHED'}


class NWChangeMixFactor(Operator, NWBase):
    bl_idname = "node.nw_factor"
    bl_label = "Change Factor"
    bl_description = "Change Factors of Mix Nodes and Mix Shader Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    # option: Change factor.
    # If option is 1.0 or 0.0 - set to 1.0 or 0.0
    # Else - change factor by option value.
    option: FloatProperty()

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        option = self.option
        selected = []  # entry = index
        for si, node in enumerate(nodes):
            if node.select:
                if node.type in {'MIX_RGB', 'MIX_SHADER'}:
                    selected.append(si)

        for si in selected:
            fac = nodes[si].inputs[0]
            nodes[si].hide = False
            if option in {0.0, 1.0}:
                fac.default_value = option
            else:
                fac.default_value += option

        return {'FINISHED'}


class NWCopySettings(Operator, NWBase):
    bl_idname = "node.nw_copy_settings"
    bl_label = "Copy Settings"
    bl_description = "Copy Settings of Active Node to Selected Nodes"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            if (
                    context.active_node is not None and
                    context.active_node.type != 'FRAME'
            ):
                valid = True
        return valid

    def execute(self, context):
        node_active = context.active_node
        node_selected = context.selected_nodes

        # Error handling
        if not (len(node_selected) > 1):
            self.report({'ERROR'}, "2 nodes must be selected at least")
            return {'CANCELLED'}

        # Check if active node is in the selection
        selected_node_names = [n.name for n in node_selected]
        if node_active.name not in selected_node_names:
            self.report({'ERROR'}, "No active node")
            return {'CANCELLED'}

        # Get nodes in selection by type
        valid_nodes = [n for n in node_selected if n.type == node_active.type]

        if not (len(valid_nodes) > 1) and node_active:
            self.report({'ERROR'}, "Selected nodes are not of the same type as {}".format(node_active.name))
            return {'CANCELLED'}

        if len(valid_nodes) != len(node_selected):
            # Report nodes that are not valid
            valid_node_names = [n.name for n in valid_nodes]
            not_valid_names = list(set(selected_node_names) - set(valid_node_names))
            self.report({'INFO'}, "Ignored {} (not of the same type as {})".format(", ".join(not_valid_names), node_active.name))

        # Reference original
        orig = node_active
        #node_selected_names = [n.name for n in node_selected]

        # Output list
        success_names = []

        # Deselect all nodes
        for i in node_selected:
            i.select = False

        # Code by zeffii from http://blender.stackexchange.com/a/42338/3710
        # Run through all other nodes
        for node in valid_nodes[1:]:

            # Check for frame node
            parent = node.parent if node.parent else None
            node_loc = [node.location.x, node.location.y]

            # Select original to duplicate
            orig.select = True

            # Duplicate selected node
            bpy.ops.node.duplicate()
            new_node = context.selected_nodes[0]

            # Deselect copy
            new_node.select = False

            # Properties to copy
            node_tree = node.id_data
            props_to_copy = 'bl_idname name location height width'.split(' ')

            # Input and outputs
            reconnections = []
            mappings = chain.from_iterable([node.inputs, node.outputs])
            for i in (i for i in mappings if i.is_linked):
                for L in i.links:
                    reconnections.append([L.from_socket.path_from_id(), L.to_socket.path_from_id()])

            # Properties
            props = {j: getattr(node, j) for j in props_to_copy}
            props_to_copy.pop(0)

            for prop in props_to_copy:
                setattr(new_node, prop, props[prop])

            # Get the node tree to remove the old node
            nodes = node_tree.nodes
            nodes.remove(node)
            new_node.name = props['name']

            if parent:
                new_node.parent = parent
                new_node.location = node_loc

            for str_from, str_to in reconnections:
                node_tree.links.new(eval(str_from), eval(str_to))

            success_names.append(new_node.name)

        orig.select = True
        node_tree.nodes.active = orig
        self.report({'INFO'}, "Successfully copied attributes from {} to: {}".format(orig.name, ", ".join(success_names)))
        return {'FINISHED'}


class NWCopyLabel(Operator, NWBase):
    bl_idname = "node.nw_copy_label"
    bl_label = "Copy Label"
    bl_options = {'REGISTER', 'UNDO'}

    option: EnumProperty(
        name="option",
        description="Source of name of label",
        items=(
            ('FROM_ACTIVE', 'from active', 'from active node',),
            ('FROM_NODE', 'from node', 'from node linked to selected node'),
            ('FROM_SOCKET', 'from socket', 'from socket linked to selected node'),
        )
    )

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        option = self.option
        active = nodes.active
        if option == 'FROM_ACTIVE':
            if active:
                src_label = active.label
                for node in [n for n in nodes if n.select and nodes.active != n]:
                    node.label = src_label
        elif option == 'FROM_NODE':
            selected = [n for n in nodes if n.select]
            for node in selected:
                for input in node.inputs:
                    if input.links:
                        src = input.links[0].from_node
                        node.label = src.label
                        break
        elif option == 'FROM_SOCKET':
            selected = [n for n in nodes if n.select]
            for node in selected:
                for input in node.inputs:
                    if input.links:
                        src = input.links[0].from_socket
                        node.label = src.name
                        break

        return {'FINISHED'}


class NWClearLabel(Operator, NWBase):
    bl_idname = "node.nw_clear_label"
    bl_label = "Clear Label"
    bl_options = {'REGISTER', 'UNDO'}

    option: BoolProperty()

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        for node in [n for n in nodes if n.select]:
            node.label = ''

        return {'FINISHED'}

    def invoke(self, context, event):
        if self.option:
            return self.execute(context)
        else:
            return context.window_manager.invoke_confirm(self, event)


class NWModifyLabels(Operator, NWBase):
    """Modify Labels of all selected nodes"""
    bl_idname = "node.nw_modify_labels"
    bl_label = "Modify Labels"
    bl_options = {'REGISTER', 'UNDO'}

    prepend: StringProperty(
        name="Add to Beginning"
    )
    append: StringProperty(
        name="Add to End"
    )
    replace_from: StringProperty(
        name="Text to Replace"
    )
    replace_to: StringProperty(
        name="Replace with"
    )

    def execute(self, context):
        nodes, links = get_nodes_links(context)
        for node in [n for n in nodes if n.select]:
            node.label = self.prepend + node.label.replace(self.replace_from, self.replace_to) + self.append

        return {'FINISHED'}

    def invoke(self, context, event):
        self.prepend = ""
        self.append = ""
        self.remove = ""
        return context.window_manager.invoke_props_dialog(self)


class NWAddTextureSetup(Operator, NWBase):
    bl_idname = "node.nw_add_texture"
    bl_label = "Texture Setup"
    bl_description = "Add Texture Node Setup to Selected Shaders"
    bl_options = {'REGISTER', 'UNDO'}

    add_mapping: BoolProperty(name="Add Mapping Nodes", description="Create coordinate and mapping nodes for the texture (ignored for selected texture nodes)", default=True)

    @classmethod
    def poll(cls, context):
        if nw_check(context):
            space = context.space_data
            if space.tree_type == 'ShaderNodeTree':
                return True
        return False

    def execute(self, context):
        nodes, links = get_nodes_links(context)

        texture_types = [x.nodetype for x in
                         get_nodes_from_category('Texture', context)]
        selected_nodes = [n for n in nodes if n.select]

        for node in selected_nodes:
            if not node.inputs:
                continue

            input_index = 0
            target_input = node.inputs[0]
            for input in node.inputs:
                if input.enabled:
                    input_index += 1
                    if not input.is_linked:
                        target_input = input
                        break
            else:
                self.report({'WARNING'}, "No free inputs for node: " + node.name)
                continue

            x_offset = 0
            padding = 40.0
            locx = node.location.x
            locy = node.location.y - (input_index * padding)

            is_texture_node = node.rna_type.identifier in texture_types
            use_environment_texture = node.type == 'BACKGROUND'

            # Add an image texture before normal shader nodes.
            if not is_texture_node:
                image_texture_type = 'ShaderNodeTexEnvironment' if use_environment_texture else 'ShaderNodeTexImage'
                image_texture_node = nodes.new(image_texture_type)
                x_offset = x_offset + image_texture_node.width + padding
                image_texture_node.location = [locx - x_offset, locy]
                nodes.active = image_texture_node
                links.new(image_texture_node.outputs[0], target_input)

                # The mapping setup following this will connect to the firrst input of this image texture.
                target_input = image_texture_node.inputs[0]

            node.select = False

            if is_texture_node or self.add_mapping:
                # Add Mapping node.
                mapping_node = nodes.new('ShaderNodeMapping')
                x_offset = x_offset + mapping_node.width + padding
                mapping_node.location = [locx - x_offset, locy]
                links.new(mapping_node.outputs[0], target_input)

                # Add Texture Coordinates node.
                tex_coord_node = nodes.new('ShaderNodeTexCoord')
                x_offset = x_offset + tex_coord_node.width + padding
                tex_coord_node.location = [locx - x_offset, locy]

                is_procedural_texture = is_texture_node and node.type != 'TEX_IMAGE'
                use_generated_coordinates = is_procedural_texture or use_environment_texture
                tex_coord_output = tex_coord_node.outputs[0 if use_generated_coordinates else 2]
                links.new(tex_coord_output, mapping_node.inputs[0])

        return {'FINISHED'}


class NWAddPrincipledSetup(Operator, NWBase, ImportHelper):
    bl_idname = "node.nw_add_textures_for_principled"
    bl_label = "Principled Texture Setup"
    bl_description = "Add Texture Node Setup for Principled BSDF"
    bl_options = {'REGISTER', 'UNDO'}

    directory: StringProperty(
        name='Directory',
        subtype='DIR_PATH',
        default='',
        description='Folder to search in for image files'
    )
    files: CollectionProperty(
        type=bpy.types.OperatorFileListElement,
        options={'HIDDEN', 'SKIP_SAVE'}
    )

    relative_path: BoolProperty(
        name='Relative Path',
        description='Set the file path relative to the blend file, when possible',
        default=True
    )

    order = [
        "filepath",
        "files",
    ]

    def draw(self, context):
        layout = self.layout
        layout.alignment = 'LEFT'

        layout.prop(self, 'relative_path')

    @classmethod
    def poll(cls, context):
        valid = False
        if nw_check(context):
            space = context.space_data
            if space.tree_type == 'ShaderNodeTree':
                valid = True
        return valid

    def execute(self, context):
        # Check if everything is ok
        if not self.directory:
            self.report({'INFO'}, 'No Folder Selected')
            return {'CANCELLED'}
        if not self.files[:]:
            self.report({'INFO'}, 'No Files Selected')
            return {'CANCELLED'}

        nodes, links = get_nodes_links(context)
        active_node = nodes.active
        if not (active_node and active_node.bl_idname == 'ShaderNodeBsdfPrincipled'):
            self.report({'INFO'}, 'Select Principled BSDF')
            return {'CANCELLED'}

        # Helper_functions
        def split_into__components(fname):
            # Split filename into components
            # 'WallTexture_diff_2k.002.jpg' -> ['Wall', 'Texture', 'diff', 'k']
            # Remove extension
            fname = path.splitext(fname)[0]
            # Remove digits
            fname = ''.join(i for i in fname if not i.isdigit())
            # Separate CamelCase by space
            fname = re.sub(r"([a-z])([A-Z])", r"\g<1> \g<2>",fname)
            # Replace common separators with SPACE
            separators = ['_', '.', '-', '__', '--', '#']
            for sep in separators:
                fname = fname.replace(sep, ' ')

            components = fname.split(' ')
            components = [c.lower() for c in components]
            return components

        # Filter textures names for texturetypes in filenames
        # [Socket Name, [abbreviations and keyword list], Filename placeholder]
        tags = context.preferences.addons[__name__].preferences.principled_tags
        normal_abbr = tags.normal.split(' ')
        bump_abbr = tags.bump.split(' ')
        gloss_abbr = tags.gloss.split(' ')
        rough_abbr = tags.rough.split(' ')
        socketnames = [
        ['Displacement', tags.displacement.split(' '), None],
        ['Base Color', tags.base_color.split(' '), None],
        ['Subsurface Color', tags.sss_color.split(' '), None],
        ['Metallic', tags.metallic.split(' '), None],
        ['Specular', tags.specular.split(' '), None],
        ['Roughness', rough_abbr + gloss_abbr, None],
        ['Normal', normal_abbr + bump_abbr, None],
        ['Transmission', tags.transmission.split(' '), None],
        ['Emission', tags.emission.split(' '), None],
        ['Alpha', tags.alpha.split(' '), None],
        ['Ambient Occlusion', tags.ambient_occlusion.split(' '), None],
        ]

        # Look through texture_types and set value as filename of first matched file
        def match_files_to_socket_names():
            for sname in socketnames:
                for file in self.files:
                    fname = file.name
                    filenamecomponents = split_into__components(fname)
                    matches = set(sname[1]).intersection(set(filenamecomponents))
                    # TODO: ignore basename (if texture is named "fancy_metal_nor", it will be detected as metallic map, not normal map)
                    if matches:
                        sname[2] = fname
                        break

        match_files_to_socket_names()
        # Remove socketnames without found files
        socketnames = [s for s in socketnames if s[2]
                       and path.exists(self.directory+s[2])]
        if not socketnames:
            self.report({'INFO'}, 'No matching images found')
            print('No matching images found')
            return {'CANCELLED'}

        # Don't override path earlier as os.path is used to check the absolute path
        import_path = self.directory
        if self.relative_path:
            if bpy.data.filepath:
                try:
                    import_path = bpy.path.relpath(self.directory)
                except ValueError:
                    pass

        # Add found images
        print('\nMatched Textures:')
        texture_nodes = []
        disp_texture = None
        ao_texture = None
        normal_node = None
        roughness_node = None
        for i, sname in enumerate(socketnames):
            print(i, sname[0], sname[2])

            # DISPLACEMENT NODES
            if sname[0] == 'Displacement':
                disp_texture = nodes.new(type='ShaderNodeTexImage')
                img = bpy.data.images.load(path.join(import_path, sname[2]))
                disp_texture.image = img
                disp_texture.label = 'Displacement'
                if disp_texture.image:
                    disp_texture.image.colorspace_settings.is_data = True

                # Add displacement offset nodes
                disp_node = nodes.new(type='ShaderNodeDisplacement')
                # Align the Displacement node under the active Principled BSDF node
                disp_node.location = active_node.location + Vector((100, -700))
                link = links.new(disp_node.inputs[0], disp_texture.outputs[0])

                # TODO Turn on true displacement in the material
                # Too complicated for now

                # Find output node
                output_node = [n for n in nodes if n.bl_idname == 'ShaderNodeOutputMaterial']
                if output_node:
                    if not output_node[0].inputs[2].is_linked:
                        link = links.new(output_node[0].inputs[2], disp_node.outputs[0])

                continue

            # AMBIENT OCCLUSION TEXTURE
            if sname[0] == 'Ambient Occlusion':
                ao_texture = nodes.new(type='ShaderNodeTexImage')
                img = bpy.data.images.load(path.join(import_path, sname[2]))
                ao_texture.image = img
                ao_texture.label = sname[0]
                if ao_texture.image:
                    ao_texture.image.colorspace_settings.is_data = True

                continue

            if not active_node.inputs[sname[0]].is_linked:
                # No texture node connected -> add texture node with new image
                texture_node = nodes.new(type='ShaderNodeTexImage')
                img = bpy.data.images.load(path.join(import_path, sname[2]))
                texture_node.image = img

                # NORMAL NODES
                if sname[0] == 'Normal':
                    # Test if new texture node is normal or bump map
                    fname_components = split_into__components(sname[2])
                    match_normal = set(normal_abbr).intersection(set(fname_components))
                    match_bump = set(bump_abbr).intersection(set(fname_components))
                    if match_normal:
                        # If Normal add normal node in between
                        normal_node = nodes.new(type='ShaderNodeNormalMap')
                        link = links.new(normal_node.inputs[1], texture_node.outputs[0])
                    elif match_bump:
                        # If Bump add bump node in between
                        normal_node = nodes.new(type='ShaderNodeBump')
                        link = links.new(normal_node.inputs[2], texture_node.outputs[0])

                    link = links.new(active_node.inputs[sname[0]], normal_node.outputs[0])
                    normal_node_texture = texture_node

                elif sname[0] == 'Roughness':
                    # Test if glossy or roughness map
                    fname_components = split_into__components(sname[2])
                    match_rough = set(rough_abbr).intersection(set(fname_components))
                    match_gloss = set(gloss_abbr).intersection(set(fname_components))

                    if match_rough:
                        # If Roughness nothing to to
                        link = links.new(active_node.inputs[sname[0]], texture_node.outputs[0])

                    elif match_gloss:
                        # If Gloss Map add invert node
                        invert_node = nodes.new(type='ShaderNodeInvert')
                        link = links.new(invert_node.inputs[1], texture_node.outputs[0])

                        link = links.new(active_node.inputs[sname[0]], invert_node.outputs[0])
                        roughness_node = texture_node

                else:
                    # This is a simple connection Texture --> Input slot
                    link = links.new(active_node.inputs[sname[0]], texture_node.outputs[0])

                # Use non-color for all but 'Base Color' Textures
                if not sname[0] in ['Base Color', 'Emission'] and texture_node.image:
                    texture_node.image.colorspace_settings.is_data = True

            else:
                # If already texture connected. add to node list for alignment
                texture_node = active_node.inputs[sname[0]].links[0].from_node

            # This are all connected texture nodes
            texture_nodes.append(texture_node)
            texture_node.label = sname[0]

        if disp_texture:
            texture_nodes.append(disp_texture)

        if ao_texture:
            # We want the ambient occlusion texture to be the top most texture node
            texture_nodes.insert(0, ao_texture)

        # Alignment
        for i, texture_node in enumerate(texture_nodes):
            offset = Vector((-550, (i * -280) + 200))
            texture_node.location = active_node.location + offset

        if normal_node:
            # Extra alignment if normal node was added
            normal_node.location = normal_node_texture.location + Vector((300, 0))

        if roughness_node:
            # Alignment of invert node if glossy map
            invert_node.location = roughness_node.location + Vector((300, 0))

        # Add texture input + mapping
        mapping = nodes.new(type='ShaderNodeMapping')
        mapping.location = active_node.location + Vector((-1050, 0))
        if len(texture_nodes) > 1:
            # If more than one texture add reroute node in between
            reroute = nodes.new(type='NodeReroute')
            texture_nodes.append(reroute)
            tex_coords = Vector((texture_nodes[0].location.x, sum(n.location.y for n in texture_nodes)/len(texture_nodes)))
            reroute.location = tex_coords + Vector((-50, -120))
            for texture_node in texture_nodes:
                link = links.new(texture_node.inputs[0], reroute.outputs[0])
            link = links.new(reroute.inputs[0], mapping.outputs[0])
        else:
            link = links.new(texture_nodes[0].inputs[0], mapping.outputs[0])

        # Connect texture_coordiantes to mapping node
        texture_input = nodes.new(type='ShaderNodeTexCoord')
        texture_input.location = mapping.location + Vector((-200, 0))
        link = links.new(mapping.inputs[0], texture_input.outputs[2])

        # Create frame around tex coords and mapping
        frame = nodes.new(type='NodeFrame')
        frame.label = 'Mapping'
        mapping.parent = frame
        texture_input.parent = frame
        frame.update()

        # Create frame around texture nodes
        frame = nodes.new(type='NodeFrame')
        frame.label = 'Textures'
        for tnode in texture_nodes:
            tnode.parent = frame
        frame.update()

        # Just to be sure
        active_node.select = False
        nodes.update()
        links.update()
        force_update(context)
        return {'FINISHED'}


class NWAddReroutes(Operator, NWBase):
    """Add Reroute Nodes and link them to outputs of selected nodes"""
    bl_idname = "node.nw_add_reroutes"
    bl_label = "Add Reroutes"
    bl_description = "Add Reroutes to Outputs"
    bl_options = {'REGISTER', 'UNDO'}

    option: EnumProperty(
        name="option",
        items=[
            ('ALL', 'to all', 'Add to all outputs'),
            ('LOOSE', 'to loose', 'Add only to loose outputs'),
            ('LINKED', 'to linked', 'Add only to linked outputs'),
        ]
    )

    def execute(self, context):
        tree_type = context.space_data.node_tree.type
        option = self.option
        nodes, links = get_nodes_links(context)
        # output valid when option is 'all' or when 'loose' output has no links
        valid = False
        post_select = []  # nodes to be selected after execution
        # create reroutes and recreate links
        for node in [n for n in nodes if n.select]:
            if node.outputs:
                x = node.location.x
                y = node.location.y
                width = node.width
                # unhide 'REROUTE' nodes to avoid issues with location.y
                if node.type == 'REROUTE':
                    node.hide = False
                # When node is hidden - width_hidden not usable.
                # Hack needed to calculate real width
                if node.hide:
                    bpy.ops.node.select_all(action='DESELECT')
                    helper = nodes.new('NodeReroute')
                    helper.select = True
                    node.select = True
                    # resize node and helper to zero. Then check locations to calculate width
                    bpy.ops.transform.resize(value=(0.0, 0.0, 0.0))
                    width = 2.0 * (helper.location.x - node.location.x)
                    # restore node location
                    node.location = x, y
                    # delete helper
                    node.select = False
                    # only helper is selected now
                    bpy.ops.node.delete()