"""Approximate threaded stud, roller body, and hex-end silhouette.

The image does not define a thread standard.  Rings represent the visible
thread rhythm while keeping the concept model lightweight and editable.
"""

from math import atan2, degrees

from build123d import Align, Axis, BuildPart, BuildSketch, Cylinder, Mode, Plane, Pos, RegularPolygon, extrude

from shaft_common import add_thread_rings, cut_end_bore, export_horizontal, stepped_body


def _hex_prism(z_start, across_corners, length):
    with BuildPart() as prism:
        with BuildSketch(Plane.XY.offset(z_start)):
            RegularPolygon(radius=across_corners / 2.0, side_count=6)
        extrude(amount=length)
    return prism.part


def _radial_through_hole(body, axial_position, surface_y, surface_z, diameter, stock_diameter):
    # The source is authored along +Z and export_horizontal rotates it onto +X.
    source_x = -surface_z
    source_y = surface_y
    angle = degrees(atan2(source_y, source_x))
    tool = (
        Pos(0, 0, axial_position)
        * Cylinder(
            diameter / 2.0,
            stock_diameter + 4.0,
            align=(Align.CENTER, Align.CENTER, Align.CENTER),
        )
        .rotate(Axis.Y, 90)
        .rotate(Axis.Z, angle)
    )
    return body - tool


def gen_step():
    # Minor thread stem, neck, roller, and short nut-supporting neck.
    body, total = stepped_body([(8.2, 40.0), (9.5, 7.0), (28.0, 25.0), (10.0, 4.0)])
    body = add_thread_rings(body, z_start=0.5, length=38.5, major_diameter=10.0, pitch=2.0)
    body = _radial_through_hole(
        body,
        axial_position=59.77433249254057,
        surface_y=0.8860768186618869,
        surface_z=13.963760796195984,
        diameter=4.0,
        stock_diameter=28.0,
    )
    hex_body = _hex_prism(total - 0.15, across_corners=22.0, length=11.0)
    body = body + hex_body
    total += 10.85
    body = cut_end_bore(body, total, diameter=8.0, depth=8.0)
    return export_horizontal(body, "threaded_roller_067249_like")