import json
import math
import os
import sys

import bpy


def mesh_object(name, vertices, edges, faces, location):
    mesh = bpy.data.meshes.new(f"{name}Mesh")
    mesh.from_pydata(vertices, edges, faces)
    mesh.update()
    obj = bpy.data.objects.new(name, mesh)
    obj.location = location
    bpy.context.scene.collection.objects.link(obj)
    return obj


def modifier_type_code(modifier):
    items = bpy.types.Modifier.bl_rna.properties["type"].enum_items
    return items[modifier.type].value


def evaluated_mesh(obj, depsgraph):
    evaluated = obj.evaluated_get(depsgraph)
    mesh = evaluated.to_mesh(preserve_all_data_layers=True, depsgraph=depsgraph)
    try:
        mesh.calc_loop_triangles()
        return {
            "object": obj.name,
            "vertexCount": len(mesh.vertices),
            "triangleCount": len(mesh.loop_triangles),
            "positions": [value for vertex in mesh.vertices for value in vertex.co],
            "indices": [index for triangle in mesh.loop_triangles for index in triangle.vertices],
        }
    finally:
        evaluated.to_mesh_clear()


def main(output_dir):
    bpy.ops.wm.read_factory_settings(use_empty=True)

    edge_split = mesh_object(
        "ExtendedEdgeSplit",
        [(0, 0, 0), (2, 0, 0), (0, 2, 0), (0, 0, 2)],
        [],
        [(0, 1, 2), (0, 3, 1)],
        (-3, 0, 0),
    )
    edge_modifier = edge_split.modifiers.new("Native Edge Split", "EDGE_SPLIT")
    edge_modifier.use_edge_angle = True
    edge_modifier.use_edge_sharp = False
    edge_modifier.split_angle = math.radians(30)

    screw = mesh_object(
        "ExtendedScrew",
        [(1, 0, -1), (1, 0, 1)],
        [(0, 1)],
        [],
        (3, 0, 0),
    )
    screw_modifier = screw.modifiers.new("Native Screw", "SCREW")
    screw_modifier.axis = "Z"
    screw_modifier.angle = math.tau
    screw_modifier.steps = 8
    screw_modifier.render_steps = 12
    screw_modifier.iterations = 1
    screw_modifier.use_merge_vertices = False

    disabled = screw.modifiers.new("Disabled Edge Split", "EDGE_SPLIT")
    disabled.show_viewport = False
    disabled.show_render = True
    disabled.show_in_editmode = True

    displace = mesh_object(
        "ExtendedDisplace",
        [(-1, -1, -1), (1, -1, -1), (1, 1, -1), (-1, 1, -1),
         (-1, -1, 1), (1, -1, 1), (1, 1, 1), (-1, 1, 1)],
        [],
        [(0, 1, 2, 3), (4, 7, 6, 5), (0, 4, 5, 1),
         (1, 5, 6, 2), (2, 6, 7, 3), (4, 0, 3, 7)],
        (7, 0, 0),
    )
    displace_modifier = displace.modifiers.new("Native Constant Displace", "DISPLACE")
    displace_modifier.direction = "Z"
    displace_modifier.space = "LOCAL"
    displace_modifier.strength = 0.75
    displace_modifier.mid_level = 0.25

    blocked_displace = mesh_object(
        "ExtendedDisplaceBlocked",
        [(-1, -1, 0), (1, -1, 0), (1, 1, 0), (-1, 1, 0)],
        [],
        [(0, 1, 2, 3)],
        (11, 0, 0),
    )
    blocked_modifier = blocked_displace.modifiers.new("Blocked RGB Displace", "DISPLACE")
    blocked_modifier.direction = "RGB_TO_XYZ"
    mesh_object(
        "ExtendedDisplaceBlockedBaseline",
        [(-1, -1, 0), (1, -1, 0), (1, 1, 0), (-1, 1, 0)],
        [],
        [(0, 1, 2, 3)],
        (15, 0, 0),
    )

    scene = bpy.context.scene
    scene.frame_set(1)
    depsgraph = bpy.context.evaluated_depsgraph_get()
    objects = [edge_split, screw, displace, blocked_displace]
    golden = {
        "schemaVersion": 1,
        "taskId": "N-002",
        "blenderVersion": bpy.app.version_string,
        "fixture": "modifier_extended_native.blend",
        "frame": scene.frame_current,
        "objects": [
            {
                "name": obj.name,
                "modifiers": [
                    {
                        "name": modifier.name,
                        "type": modifier.type,
                        "typeCode": modifier_type_code(modifier),
                        "showViewport": modifier.show_viewport,
                        "showRender": modifier.show_render,
                        "showEditmode": modifier.show_in_editmode,
                        "showOnCage": modifier.show_on_cage,
                    }
                    for modifier in obj.modifiers
                ],
            }
            for obj in objects
        ],
        "meshes": [evaluated_mesh(obj, depsgraph) for obj in objects],
        "tolerance": {"maxPositionError": 1e-5, "rmsPositionError": 1e-6},
    }

    os.makedirs(output_dir, exist_ok=True)
    output_path = os.path.join(output_dir, golden["fixture"])
    bpy.ops.wm.save_as_mainfile(filepath=output_path)
    golden_dir = os.path.abspath(os.path.join(output_dir, "..", "..", "golden", "N-002"))
    os.makedirs(golden_dir, exist_ok=True)
    with open(os.path.join(golden_dir, "modifier_extended_native.json"), "w", encoding="utf-8") as handle:
        json.dump(golden, handle, indent=2, sort_keys=True)
        handle.write("\n")
    print(f"modifier-extended-generated fixture={output_path}")


if __name__ == "__main__":
    args = sys.argv[sys.argv.index("--") + 1:]
    main(os.path.abspath(args[0]))