"""The standard-parts catalogue: search, designations, block specs, insertion.

Geometry is asserted as emitted primitive dicts - counts, layers, coordinates -
never as a screenshot.
"""

from __future__ import annotations

import math

import pytest

from backends.block_specs import validate_attdef_specs, validate_entity_specs
from engineering.mech.stdparts import (
    FAMILY_STANDARDS,
    FAMILY_VIEWS,
    THREAD_MINOR_RATIO,
    block_spec,
    catalogue,
    parse_designation,
)

R12 = 2.0 * 18.0 / math.sqrt(3.0) / 2.0  # across-corners radius of an M12 hex head
MINOR12 = THREAD_MINOR_RATIO * 12.0 / 2.0  # ISO 6410 minor radius of an M12 thread


def test_the_iso6410_minor_radius_is_four_point_eight():
    """Pinned as the builder computes it: 0.8 * 12 / 2 is 4.800000000000001 in binary."""
    assert MINOR12 == pytest.approx(4.8)


def test_the_catalogue_holds_every_transcribed_size():
    rows = catalogue()
    assert len(rows) == 83  # 5 fastener standards x 10 sizes + 33 bearings
    assert len(catalogue(standard="ISO 15")) == 33
    assert len(catalogue("M12")) == 5
    assert len(catalogue("6205")) == 1
    assert {row["standard"] for row in rows} == set(FAMILY_STANDARDS)


def test_a_catalogue_row_carries_what_a_drawing_needs():
    (row,) = catalogue("6205")
    assert row["designation"] == "ISO 15 - 6205"
    assert row["standard"] == "ISO 15"
    assert row["family"] == "deep_groove_bearing"
    assert row["views"] == ["simplified", "detailed"]
    assert row["length_required"] is False
    assert row["dims"] == {"d": 25.0, "D": 52.0, "B": 15.0}
    assert "ISO 15:2017" in row["source"]

    bolt = next(r for r in catalogue(standard="ISO 4014") if r["size"] == "M12")
    assert bolt["length_required"] is True
    assert bolt["dims"]["s"] == 18.0 and bolt["dims"]["k"] == 7.5


def test_catalogue_refuses_an_unknown_standard():
    with pytest.raises(ValueError, match="ISO 4014"):
        catalogue(standard="DIN 931")


def test_parse_designation_normalises_and_splits():
    assert parse_designation("iso4014 - m12x60") == {
        "designation": "ISO 4014 - M12x60",
        "standard": "ISO 4014",
        "family": "hex_bolt",
        "size": "M12x60",
        "thread": "M12",
        "length": 60.0,
    }
    assert parse_designation("6205")["designation"] == "ISO 15 - 6205"
    assert parse_designation("ISO 4032 - M12")["length"] is None


def test_parse_designation_refuses_a_missing_or_stray_length():
    with pytest.raises(ValueError, match="nominal length"):
        parse_designation("ISO 4014 - M12")
    with pytest.raises(ValueError, match="takes no length"):
        parse_designation("ISO 4032 - M12x60")
    with pytest.raises(ValueError, match="catalogue standard"):
        parse_designation("ISO 9999 - M12")


def test_an_unknown_size_is_refused_with_the_nearest_entries():
    with pytest.raises(ValueError, match=r"ISO 4014 - M12"):
        block_spec("ISO 4014 - M13x60", "side")
    with pytest.raises(ValueError, match=r"ISO 15 - 6210"):
        block_spec("ISO 15 - 6211", "simplified")
    with pytest.raises(ValueError, match="approximately"):
        block_spec("ISO 4014 - M13x60", "side")


def test_hex_bolt_side_view_is_the_iso6410_representation():
    spec = block_spec("ISO 4014 - M12x60", "side")
    assert spec["name"] == "STD_ISO_4014_M12X60_SIDE"
    assert spec["view"] == "side"
    assert spec["dims"]["b"] == pytest.approx(30.0)  # 2d + 6 for l <= 125
    ents = spec["entities"]
    assert len(ents) == 10
    assert ents[0]["type"] == "polyline" and ents[0]["closed"] is True
    assert ents[0]["points"] == [
        [-7.5, -R12],
        [0.0, -R12],
        [0.0, R12],
        [-7.5, R12],
    ]
    assert ents[3] == {
        "type": "line",
        "x1": 0.0,
        "y1": 6.0,
        "x2": 60.0,
        "y2": 6.0,
        "layer": "GEOMETRY",
    }
    # ISO 6410: minor diameter at 0.8 x major, over the useful thread length.
    assert ents[6] == {
        "type": "line",
        "x1": 30.0,
        "y1": MINOR12,
        "x2": 60.0,
        "y2": MINOR12,
        "layer": "GEOMETRY",
    }
    # ISO 6410: the thread-length limit is a line to the major diameter.
    assert ents[8] == {
        "type": "line",
        "x1": 30.0,
        "y1": -6.0,
        "x2": 30.0,
        "y2": 6.0,
        "layer": "GEOMETRY",
    }
    assert ents[9]["layer"] == "CENTER"
    assert spec["bbox"] == pytest.approx((-10.5, -R12, 63.0, R12))


def test_a_fully_threaded_screw_has_no_thread_limit_line():
    spec = block_spec("ISO 4017 - M12x60", "side")
    assert len(spec["entities"]) == 9
    assert spec["dims"]["b"] == pytest.approx(60.0)
    minor = [e for e in spec["entities"] if e.get("y1") == MINOR12]
    assert minor[0]["x1"] == 0.0 and minor[0]["x2"] == 60.0


def test_hex_top_view_uses_the_three_quarter_minor_arc():
    spec = block_spec("ISO 4014 - M12x60", "top")
    ents = spec["entities"]
    assert len(ents) == 5
    assert ents[0]["type"] == "polyline" and len(ents[0]["points"]) == 6
    assert ents[1] == {"type": "circle", "cx": 0.0, "cy": 0.0, "r": 6.0, "layer": "GEOMETRY"}
    assert ents[2] == {
        "type": "arc",
        "cx": 0.0,
        "cy": 0.0,
        "r": MINOR12,
        "start_deg": 90.0,
        "end_deg": 360.0,
        "layer": "GEOMETRY",
    }
    assert ents[3]["layer"] == "CENTER" and ents[4]["layer"] == "CENTER"


def test_hex_nut_side_view_shows_the_thread_as_hidden_lines():
    spec = block_spec("ISO 4032 - M12", "side")
    ents = spec["entities"]
    assert len(ents) == 8
    hidden = [e for e in ents if e["layer"] == "HIDDEN"]
    assert len(hidden) == 4
    assert {abs(e["y1"]) for e in hidden} == {6.0, MINOR12}
    assert ents[0]["points"][1] == [10.8, -R12]  # nut height m


def test_washer_views():
    side = block_spec("ISO 7089 - M12", "side")
    assert len(side["entities"]) == 3
    assert side["entities"][0]["points"] == [[0.0, 6.5], [2.5, 6.5], [2.5, 12.0], [0.0, 12.0]]
    top = block_spec("ISO 7089 - M12", "top")
    assert top["entities"][0] == {
        "type": "circle",
        "cx": 0.0,
        "cy": 0.0,
        "r": 12.0,
        "layer": "GEOMETRY",
    }
    assert top["entities"][1]["r"] == 6.5


def test_socket_head_screw_views():
    side = block_spec("ISO 4762 - M8x30", "side")
    assert len(side["entities"]) == 8
    assert side["dims"]["b"] == pytest.approx(28.0)
    assert side["entities"][0]["points"][0] == [-8.0, -6.5]  # k = 8, dk/2 = 6.5
    top = block_spec("ISO 4762 - M8x30", "top")
    assert top["entities"][0]["r"] == 6.5
    assert len(top["entities"][1]["points"]) == 6  # the hexagon socket, s = 6


def test_bearing_simplified_is_the_iso8826_1_outline_and_cross():
    spec = block_spec("ISO 15 - 6205", "simplified")
    ents = spec["entities"]
    assert len(ents) == 7
    assert ents[0]["points"] == [[-7.5, 12.5], [7.5, 12.5], [7.5, 26.0], [-7.5, 26.0]]
    assert ents[1]["points"] == [[-7.5, -12.5], [7.5, -12.5], [7.5, -26.0], [-7.5, -26.0]]
    assert ents[2] == {
        "type": "line",
        "x1": -4.5,
        "y1": 19.25,
        "x2": 4.5,
        "y2": 19.25,
        "layer": "GEOMETRY",
    }
    assert ents[3] == {
        "type": "line",
        "x1": 0.0,
        "y1": 15.2,
        "x2": 0.0,
        "y2": 23.3,
        "layer": "GEOMETRY",
    }
    assert ents[6]["layer"] == "CENTER"


def test_bearing_detailed_draws_the_element_symbol():
    spec = block_spec("ISO 15 - 6205", "detailed")
    ents = spec["entities"]
    assert len(ents) == 5
    assert ents[2] == {
        "type": "circle",
        "cx": 0.0,
        "cy": 19.25,
        "r": 4.05,
        "layer": "GEOMETRY",
    }
    assert ents[3]["cy"] == -19.25


def test_a_view_the_family_does_not_have_is_refused_and_side_falls_back():
    assert block_spec("ISO 15 - 6205", "side")["view"] == "simplified"
    with pytest.raises(ValueError, match="simplified"):
        block_spec("ISO 15 - 6205", "top")
    with pytest.raises(ValueError, match="side"):
        block_spec("ISO 4014 - M12x60", "simplified")


@pytest.mark.parametrize(
    ("designation", "view"),
    [
        ("ISO 4014 - M12x60", "side"),
        ("ISO 4014 - M12x60", "top"),
        ("ISO 4017 - M12x60", "side"),
        ("ISO 4032 - M12", "side"),
        ("ISO 4032 - M12", "top"),
        ("ISO 7089 - M12", "side"),
        ("ISO 7089 - M12", "top"),
        ("ISO 4762 - M8x30", "side"),
        ("ISO 4762 - M8x30", "top"),
        ("ISO 15 - 6205", "simplified"),
        ("ISO 15 - 6205", "detailed"),
    ],
)
def test_every_block_spec_validates_against_block_define(designation, view):
    spec = block_spec(designation, view)
    validate_entity_specs(spec["entities"])
    validate_attdef_specs(spec["attdefs"])
    assert [att["tag"] for att in spec["attdefs"]] == ["DESIG", "STD", "SIZE", "MAT"]
    assert spec["attdefs"][0]["default"] == spec["designation"]
    assert spec["attdefs"][0]["invisible"] is False
    assert all(att["invisible"] for att in spec["attdefs"][1:])
    assert spec["bbox"][0] < spec["bbox"][2] and spec["bbox"][1] < spec["bbox"][3]
    assert set(FAMILY_VIEWS[spec["family"]]) >= {spec["view"]}


@pytest.mark.asyncio
async def test_insert_defines_the_block_once_and_writes_the_payload(backend):
    from engineering.mech.stdparts import insert_std_part
    from engineering.mech.xdata import APP_ID, decode

    result = await insert_std_part(backend, "ISO 4014 - M12x60", at=(100.0, 50.0), material="8.8")
    assert result["ok"] is True
    assert result["block_name"] == "STD_ISO_4014_M12X60_SIDE"
    assert result["defined"] is True
    assert sorted(result["layers_created"]) == ["CENTER", "GEOMETRY"]
    assert result["view"] == "side"
    assert result["layer"] == "GEOMETRY"
    assert result["dims"]["s"] == 18.0

    stored = await backend.entity_get_xdata(result["handle"], APP_ID)
    payload = decode([(1001, APP_ID)] + [(1000, value) for value in stored["xdata"][APP_ID]])
    assert payload == {
        "v": 1,
        "kind": "std_part",
        "designation": "ISO 4014 - M12x60",
        "standard": "ISO 4014",
        "size": "M12x60",
        "qty": 1,
        "material": "8.8",
    }
    assert await backend.block_get_attributes(result["handle"]) == {
        "DESIG": "ISO 4014 - M12x60",
        "STD": "ISO 4014",
        "SIZE": "M12x60",
        "MAT": "8.8",
    }

    again = await insert_std_part(backend, "ISO 4014 - M12x60", at=(200.0, 50.0))
    assert again["defined"] is False and again["layers_created"] == []
    assert again["payload"]["material"] == ""


@pytest.mark.asyncio
async def test_bearing_inserts_with_its_own_view_name(backend):
    from engineering.mech.stdparts import insert_std_part

    result = await insert_std_part(backend, "6205", at=(0.0, 0.0), rotation=90.0)
    assert result["block_name"] == "STD_ISO_15_6205_SIMPLIFIED"
    assert result["view"] == "simplified"
    assert result["rotation"] == 90.0
    assert result["dims"]["B"] == 15.0


@pytest.mark.asyncio
async def test_insert_refuses_before_writing_anything(backend):
    from engineering.mech.stdparts import insert_std_part

    before = len(await backend.entity_list())
    with pytest.raises(ValueError, match="Nearest entries"):
        await insert_std_part(backend, "ISO 4014 - M13x60", at=(0.0, 0.0))
    with pytest.raises(ValueError, match="finite"):
        await insert_std_part(backend, "ISO 4014 - M12x60", at=(float("nan"), 0.0))
    with pytest.raises(ValueError, match="no attribute"):
        await insert_std_part(
            backend, "ISO 4014 - M12x60", at=(0.0, 0.0), attributes={"TORQUE": "80"}
        )
    assert len(await backend.entity_list()) == before