"""Parametric V1 connecting-rod sample routed to the build123d backend."""

from math import atan2, degrees, hypot

from build123d import (
    Align,
    Box,
    BuildPart,
    BuildSketch,
    Cylinder,
    Location,
    Locations,
    Mode,
    Plane,
    SlotOverall,
    extrude,
    fillet,
)


CENTER_DISTANCE = 120.0
THICKNESS = 14.0

BIG_END_OUTER_DIAMETER = 56.0
BIG_END_BORE_DIAMETER = 36.0
SMALL_END_OUTER_DIAMETER = 36.0
SMALL_END_BORE_DIAMETER = 20.0

WEB_WIDTH = 24.0
POCKET_LENGTH = 72.0
POCKET_WIDTH = 12.0
POCKET_DEPTH = 3.0

VIEWER_SLOT_START = (-28.73179347578467, -0.3844822039559189)
VIEWER_SLOT_END = (24.36043904920138, -0.24367243243227724)
VIEWER_SLOT_SURFACE_Z = THICKNESS - POCKET_DEPTH
VIEWER_SLOT_WIDTH = 2.0
VIEWER_SLOT_BLIND_DEPTH = 2.0
VIEWER_EDGE_E14_FILLET_RADIUS = 1.0
VIEWER_HOLE_CENTER = (-22.122781376227962, -9.435525387895417)
VIEWER_HOLE_DIAMETER = 6.0
VIEWER_HOLE_BLIND_DEPTH = 6.0
VIEWER_HOLE_SURFACE_Z = THICKNESS
VIEWER_HOLE_BOOLEAN_OVERTRAVEL = 0.2

VIEWER_SLOT_CENTER = (
    (VIEWER_SLOT_START[0] + VIEWER_SLOT_END[0]) / 2.0,
    (VIEWER_SLOT_START[1] + VIEWER_SLOT_END[1]) / 2.0,
)
VIEWER_SLOT_LENGTH = hypot(
    VIEWER_SLOT_END[0] - VIEWER_SLOT_START[0],
    VIEWER_SLOT_END[1] - VIEWER_SLOT_START[1],
)
VIEWER_SLOT_ROTATION = degrees(
    atan2(
        VIEWER_SLOT_END[1] - VIEWER_SLOT_START[1],
        VIEWER_SLOT_END[0] - VIEWER_SLOT_START[0],
    )
)


def _viewer_edge_e14(part):
    """Select the big-end top outer edge selected in CAD Viewer as e14."""
    selected_edges = []
    for edge in part.edges():
        try:
            edge_radius = edge.radius
            edge_center = edge.arc_center
            edge_normal = edge.normal()
        except Exception:
            continue

        if abs(edge_radius - BIG_END_OUTER_DIAMETER / 2.0) > 0.05:
            continue
        if abs(edge_center.X + CENTER_DISTANCE / 2.0) > 0.05:
            continue
        if abs(edge_center.Y) > 0.05:
            continue
        if abs(edge_center.Z - THICKNESS) > 0.05:
            continue
        if abs(edge_normal.Z) < 1.0 - 1e-4:
            continue
        selected_edges.append(edge)

    if len(selected_edges) != 1:
        raise RuntimeError(f"Expected one viewer-selected e14 edge, found {len(selected_edges)}")
    return selected_edges


def gen_step():
    """Return a closed, STEP-ready connecting-rod solid in millimeters."""
    half_distance = CENTER_DISTANCE / 2.0

    with BuildPart() as rod:
        with Locations(Location((-half_distance, 0.0, 0.0))):
            Cylinder(
                radius=BIG_END_OUTER_DIAMETER / 2.0,
                height=THICKNESS,
                align=(Align.CENTER, Align.CENTER, Align.MIN),
            )

        with Locations(Location((half_distance, 0.0, 0.0))):
            Cylinder(
                radius=SMALL_END_OUTER_DIAMETER / 2.0,
                height=THICKNESS,
                align=(Align.CENTER, Align.CENTER, Align.MIN),
            )

        Box(
            CENTER_DISTANCE,
            WEB_WIDTH,
            THICKNESS,
            align=(Align.CENTER, Align.CENTER, Align.MIN),
        )

        with Locations(Location((-half_distance, 0.0, -1.0))):
            Cylinder(
                radius=BIG_END_BORE_DIAMETER / 2.0,
                height=THICKNESS + 2.0,
                align=(Align.CENTER, Align.CENTER, Align.MIN),
                mode=Mode.SUBTRACT,
            )

        with Locations(Location((half_distance, 0.0, -1.0))):
            Cylinder(
                radius=SMALL_END_BORE_DIAMETER / 2.0,
                height=THICKNESS + 2.0,
                align=(Align.CENTER, Align.CENTER, Align.MIN),
                mode=Mode.SUBTRACT,
            )

        with BuildSketch(Plane.XY):
            SlotOverall(width=POCKET_LENGTH, height=POCKET_WIDTH)
        extrude(amount=POCKET_DEPTH, mode=Mode.SUBTRACT)

        with BuildSketch(Plane.XY.offset(THICKNESS - POCKET_DEPTH)):
            SlotOverall(width=POCKET_LENGTH, height=POCKET_WIDTH)
        extrude(amount=POCKET_DEPTH, mode=Mode.SUBTRACT)

        with BuildSketch(Plane.XY.offset(VIEWER_SLOT_SURFACE_Z - VIEWER_SLOT_BLIND_DEPTH)):
            with Locations(Location((VIEWER_SLOT_CENTER[0], VIEWER_SLOT_CENTER[1], 0.0))):
                SlotOverall(
                    width=VIEWER_SLOT_LENGTH,
                    height=VIEWER_SLOT_WIDTH,
                    rotation=VIEWER_SLOT_ROTATION,
                )
        extrude(amount=VIEWER_SLOT_BLIND_DEPTH, mode=Mode.SUBTRACT)

        with Locations(
            Location(
                (
                    VIEWER_HOLE_CENTER[0],
                    VIEWER_HOLE_CENTER[1],
                    VIEWER_HOLE_SURFACE_Z - VIEWER_HOLE_BLIND_DEPTH,
                )
            )
        ):
            Cylinder(
                radius=VIEWER_HOLE_DIAMETER / 2.0,
                height=VIEWER_HOLE_BLIND_DEPTH + VIEWER_HOLE_BOOLEAN_OVERTRAVEL,
                align=(Align.CENTER, Align.CENTER, Align.MIN),
                mode=Mode.SUBTRACT,
            )

    result = rod.part
    result = fillet(_viewer_edge_e14(result), radius=VIEWER_EDGE_E14_FILLET_RADIUS)
    result.label = "cad_router_v1_connecting_rod"
    return result