# gpl author: Stanislav Blinov

bl_info = {
    "name": "Cut Faces",
    "author": "Stanislav Blinov",
    "version": (1, 0, 0),
    "blender": (2, 72, 0),
    "description": "Cut Faces and Deselect Boundary operators",
    "category": "Mesh", }

import bpy
import bmesh
from bpy.types import Operator
from bpy.props import (
        BoolProperty,
        IntProperty,
        EnumProperty,
        )


def bmesh_from_object(object):
    mesh = object.data
    if object.mode == 'EDIT':
        bm = bmesh.from_edit_mesh(mesh)
    else:
        bm = bmesh.new()
        bm.from_mesh(mesh)
    return bm


def bmesh_release(bm, object):
    mesh = object.data
    bm.select_flush_mode()
    if object.mode == 'EDIT':
        bmesh.update_edit_mesh(mesh, True)
    else:
        bm.to_mesh(mesh)
        bm.free()


def calc_face(face, keep_caps=True):

    assert face.tag

    def radial_loops(loop):
        next = loop.link_loop_radial_next
        while next != loop:
            result, next = next, next.link_loop_radial_next
            yield result

    result = []

    face.tag = False
    selected = []
    to_select = []
    for loop in face.loops:
        self_selected = False
        # Iterate over selected adjacent faces
        for radial_loop in filter(lambda l: l.face.select, radial_loops(loop)):
            # Tag the edge if no other face done so already
            if not loop.edge.tag:
                loop.edge.tag = True
                self_selected = True

            adjacent_face = radial_loop.face
            # Only walk adjacent face if current face tagged the edge
            if adjacent_face.tag and self_selected:
                result += calc_face(adjacent_face, keep_caps)

        if loop.edge.tag:
            (selected, to_select)[self_selected].append(loop)

    for loop in to_select:
        result.append(loop.edge)
        selected.append(loop)

    # Select opposite edge in quads
    if keep_caps and len(selected) == 1 and len(face.verts) == 4:
        result.append(selected[0].link_loop_next.link_loop_next.edge)

    return result


def get_edge_rings(bm, keep_caps=True):

    def tag_face(face):
        if face.select:
            face.tag = True
            for edge in face.edges:
                edge.tag = False
        return face.select

    # fetch selected faces while setting up tags
    selected_faces = [f for f in bm.faces if tag_face(f)]

    edges = []

    try:
        # generate a list of edges to select:
        # traversing only tagged faces, since calc_face can walk and untag islands
        for face in filter(lambda f: f.tag, selected_faces):
            edges += calc_face(face, keep_caps)
    finally:
        # housekeeping: clear tags
        for face in selected_faces:
            face.tag = False
            for edge in face.edges:
                edge.tag = False

    return edges


class MESH_xOT_deselect_boundary(Operator):
    bl_idname = "mesh.ext_deselect_boundary"
    bl_label = "Deselect Boundary"
    bl_description = ("Deselect boundary edges of selected faces\n"
                      "Note: if all Faces are selected there is no boundary,\n"
                      "so the tool will not have results")
    bl_options = {'REGISTER', 'UNDO'}

    keep_cap_edges = BoolProperty(
                        name="Keep Cap Edges",
                        description="Keep quad strip cap edges selected",
                        default=False
                        )

    @classmethod
    def poll(cls, context):
        active_object = context.active_object
        return active_object and active_object.type == 'MESH' and active_object.mode == 'EDIT'

    def execute(self, context):
        object = context.active_object
        bm = bmesh_from_object(object)

        try:
            edges = get_edge_rings(bm, keep_caps=self.keep_cap_edges)
            if not edges:
                self.report({'WARNING'}, "No suitable Face selection found. Operation cancelled")
                return {'CANCELLED'}

            bpy.ops.mesh.select_all(action='DESELECT')
            bm.select_mode = {'EDGE'}

            for edge in edges:
                edge.select = True
            context.tool_settings.mesh_select_mode[:] = False, True, False

        finally:
            bmesh_release(bm, object)

        return {'FINISHED'}


class MESH_xOT_cut_faces(Operator):
    bl_idname = "mesh.ext_cut_faces"
    bl_label = "Cut Faces"
    bl_description = "Cut selected faces, connected through their adjacent edges"
    bl_options = {'REGISTER', 'UNDO'}

    # from bmesh_operators.h
    SUBD_INNERVERT = 0
    SUBD_PATH = 1
    SUBD_FAN = 2
    SUBD_STRAIGHT_CUT = 3

    num_cuts = IntProperty(
            name="Number of Cuts",
            default=1,
            min=1,
            max=100,
            subtype='UNSIGNED'
            )
    use_single_edge = BoolProperty(
            name="Quad/Tri Mode",
            description="Cut boundary faces",
            default=False
            )
    corner_type = EnumProperty(
            items=[('SUBD_INNERVERT', "Inner Vert", ""),
                   ('SUBD_PATH', "Path", ""),
                   ('SUBD_FAN', "Fan", ""),
                   ('SUBD_STRAIGHT_CUT', "Straight Cut", ""),
                   ],
            name="Quad Corner Type",
            description="How to subdivide quad corners",
            default='SUBD_STRAIGHT_CUT'
            )
    use_grid_fill = BoolProperty(
            name="Use Grid Fill",
            description="Fill fully enclosed faces with a grid",
            default=True
            )

    @classmethod
    def poll(cls, context):
        active_object = context.active_object
        return active_object and active_object.type == 'MESH' and active_object.mode == 'EDIT'

    def draw(self, context):
        layout = self.layout

        layout.label("Number of Cuts:")
        layout.prop(self, "num_cuts", text="")

        layout.prop(self, "use_single_edge")
        layout.prop(self, "use_grid_fill")

        layout.label("Quad Corner Type:")
        layout.prop(self, "corner_type", text="")

    def cut_edges(self, context):
        object = context.active_object
        bm = bmesh_from_object(object)

        try:
            edges = get_edge_rings(bm, keep_caps=True)
            if not edges:
                self.report({'WARNING'},
                            "No suitable Face selection found. Operation cancelled")
                return False

            result = bmesh.ops.subdivide_edges(
                            bm,
                            edges=edges,
                            cuts=int(self.num_cuts),
                            use_grid_fill=bool(self.use_grid_fill),
                            use_single_edge=bool(self.use_single_edge),
                            quad_corner_type=eval("self." + self.corner_type)
                            )
            bpy.ops.mesh.select_all(action='DESELECT')
            bm.select_mode = {'EDGE'}

            inner = result['geom_inner']
            for edge in filter(lambda e: isinstance(e, bmesh.types.BMEdge), inner):
                edge.select = True

        finally:
            bmesh_release(bm, object)

        return True

    def execute(self, context):

        if not self.cut_edges(context):
            return {'CANCELLED'}

        context.tool_settings.mesh_select_mode[:] = False, True, False
        # Try to select all possible loops
        bpy.ops.mesh.loop_multi_select(ring=False)

        return {'FINISHED'}


def register():
    bpy.utils.register_class(MESH_xOT_deselect_boundary)
    bpy.utils.register_class(MESH_xOT_cut_faces)


def unregister():
    bpy.utils.unregister_class(MESH_xOT_deselect_boundary)
    bpy.utils.unregister_class(MESH_xOT_cut_faces)


if __name__ == "__main__":
    register()