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


from . import utilities_uv
from . import utilities_ui

class op(bpy.types.Operator):
    bl_idname = "uv.textools_smoothing_uv_islands"
    bl_label = "Apply smooth normals and hard edges for UV Island borders."
    bl_description = "Set mesh smoothing by uv islands"
    bl_options = {'REGISTER', 'UNDO'}
    
    @classmethod
    def poll(cls, context):
        if not bpy.context.active_object:
            return False
        
        if bpy.context.active_object.type != 'MESH':
            return False

        #Requires UV map
        if not bpy.context.object.data.uv_layers:
            return False

        return True
    
    def execute(self, context):
        smooth_uv_islands(self, context)
        return {'FINISHED'}



def smooth_uv_islands(self, context):
    if bpy.context.active_object.mode != 'EDIT':
        bpy.ops.object.mode_set(mode='EDIT')

    bm = bmesh.from_edit_mesh(bpy.context.active_object.data);
    uv_layers = bm.loops.layers.uv.verify();

    # Smooth everything
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
    bpy.ops.mesh.select_all(action='SELECT')
    bpy.ops.mesh.faces_shade_smooth()
    bpy.ops.mesh.mark_sharp(clear=True)

    # Select Edges
    bpy.ops.mesh.select_all(action='DESELECT')
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='EDGE')
    bpy.ops.uv.textools_select_islands_outline()
    bpy.ops.mesh.mark_sharp()
    bpy.ops.mesh.select_all(action='DESELECT')
    
    # Apply Edge split modifier
    bpy.context.object.data.use_auto_smooth = True
    bpy.context.object.data.auto_smooth_angle = math.pi

    # bpy.ops.object.modifier_add(type='EDGE_SPLIT')
    # bpy.context.object.modifiers["EdgeSplit"].use_edge_angle = False

    bpy.ops.object.mode_set(mode='OBJECT')

bpy.utils.register_class(op)