import bpy
import bmesh
from mathutils import Vector
from collections import defaultdict
from dataclasses import dataclass

def sprint(*text):
    screen = bpy.data.screens['Scripting']
    for area in screen.areas:
        if area.type != "CONSOLE":
            continue
        override = {'screen': screen, 'area': area}
        with bpy.context.temp_override(**override):
            bpy.ops.console.scrollback_append(text=" ".join(map(str, text)))

print = sprint

def face_indicators(light: Vector,
                    position: list[Vector],
                    polygon_normal: list[Vector],
                    mesh: bpy.types.Mesh,
                    # outputs
                    indicators: list[float]):
    for i in range(len(mesh.polygons)):
        n = polygon_normal[i]
        p = position[mesh.polygons[i].a]
        indicator = dot(n, (light - p))
        indicators[i] = indicator

@dataclass
class Edge:
    a: int # vertex index
    b: int # vertex index

@dataclass
class PolygonIndex:
    a: int
    b: int

@dataclass
class EdgePolygon:
    edge: Edge
    polygon_index: PolygonIndex

def build_edge_polygons(mesh: bpy.types.Mesh):
    by_edge = defaultdict(list)
    for i, polygon in enumerate(mesh.polygons):
        for edge in polygon.edge_keys:
            by_edge[frozenset(edge)].append(i)

    assert all(len(p) == 2 for p in by_edge.values())

    return [
        EdgePolygon(Edge(*edge), PolygonIndex(*polygons))
        for edge, polygons in by_edge.items()
    ]

def object_silhouette(indicators: list[float],
                      mesh: bpy.types.Mesh,
                      # outputs
                      edge_indices: list[int]):
    ix = 0

    edge_polygons = build_edge_polygons(mesh)

    for i in range(len(edge_polygons)):
        ep = edge_polygons[i]
        if (indicators[ep.polygon_index.a] > 0) != (indicators[ep.polygon_index.b]):
            edge_indices[ix] = i
            ix += 1

    return ix

def select_edge(bm, edge):
    for e in bm.edges:
        if frozenset((e.verts[0].index, e.verts[1].index)) == frozenset(edge):
            e.select = True

def select():
    light = bpy.data.objects['Light']
    torus = bpy.data.objects['Torus']

    position = [0] * len(

    obj = bpy.context.edit_object
    bm = bmesh.from_edit_mesh(obj.data)



    bmesh.update_edit_mesh(obj.data)