import bpy
import bmesh
import operator
from mathutils import Vector
from collections import defaultdict
from math import pi

from . import utilities_ui

class op(bpy.types.Operator):
    bl_idname = "uv.textools_uv_channel_add"
    bl_label = "Add UV Channel"
    bl_description = "Add a new UV channel with smart UV projected UV's and padding."
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        if bpy.context.active_object == None:
            return False
        if bpy.context.active_object.type != 'MESH':
            return False
        return True


    @classmethod
    def poll(cls, context):
        if bpy.context.active_object == None:
            return False
        if bpy.context.active_object.type != 'MESH':
            return False
        if  len(bpy.context.selected_objects) != 1:
            return False

        return True

    def execute(self, context):
        print("Add UV")
        
        if len( bpy.context.object.data.uv_layers ) == 0:
            # Create first UV channel
            if bpy.context.active_object.mode != 'EDIT':
                bpy.ops.object.mode_set(mode='EDIT')

            # Smart project UV's
            bpy.ops.mesh.select_all(action='SELECT')
            bpy.ops.uv.smart_project(
                angle_limit=65, 
                island_margin=0.5, 
                user_area_weight=0, 
                use_aspect=True, 
                stretch_to_bounds=True
            )

            # Re-Apply padding as normalized values
            bpy.ops.uv.select_all(action='SELECT')
            bpy.ops.uv.pack_islands(margin=utilities_ui.get_padding())
        else:
            # Add new UV channel based on last
            bpy.ops.mesh.uv_texture_add()

        # Get current index
        index = len(bpy.context.object.data.uv_layers)-1
        bpy.context.object.data.uv_layers.active_index = index
        bpy.context.scene.texToolsSettings.uv_channel = str(index)
        return {'FINISHED'}

bpy.utils.register_class(op)