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

from . import utilities_uv
from . import utilities_ui


class op(bpy.types.Operator):
    bl_idname = "uv.textools_unwrap_edge_peel"
    bl_label = "Peel Edge"
    bl_description = "Unwrap pipe along selected edges"
    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

        # Only in Edit mode
        if bpy.context.active_object.mode != 'EDIT':
            return False

        # Need view Face mode
        if tuple(bpy.context.scene.tool_settings.mesh_select_mode)[1] == False:
            return False

        return True

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


def unwrap_edges_pipe(self, context):

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

    contextViewUV = utilities_ui.GetContextViewUV()
    if not contextViewUV:
        self.report({'ERROR_INVALID_INPUT'},
                    "This tool requires an available UV/Image view.")
        return

    # selected_initial = [edge for edge in bm.edges if edge.select]
    selected_edges = []
    selected_faces = []

    # Extend loop selection
    bpy.ops.mesh.loop_multi_select(ring=False)
    selected_edges = [edge for edge in bm.edges if edge.select]

    if len(selected_edges) == 0:
        self.report({'ERROR_INVALID_INPUT'}, "No edges selected in the view")
        return

    # Convert linked selection to single UV island
    bpy.ops.mesh.select_linked(delimit=set())
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
    bpy.ops.uv.textools_unwrap_faces_iron()
    selected_faces = [face for face in bm.faces if face.select]

    if len(selected_faces) == 0:
        self.report({'ERROR_INVALID_INPUT'}, "No faces available")
        return

    # Mark previous selected edges as Seam
    bpy.ops.mesh.select_all(action='DESELECT')
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='EDGE')
    for edge in selected_edges:
        edge.select = True
    bpy.ops.mesh.mark_seam(clear=False)

    # Follow active quad unwrap for faces
    bpy.ops.mesh.select_all(action='DESELECT')
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
    for face in selected_faces:
        face.select = True
    bm.faces.active = selected_faces[0]

    bpy.ops.uv.unwrap(method='ANGLE_BASED', margin=0.0226216)
    bpy.ops.uv.select_all(action='SELECT')
    bpy.ops.uv.textools_rectify(contextViewUV)

    # TODO: Restore initial selection
    bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='EDGE')


bpy.utils.register_class(op)