"""Taxonomy loader is src; JSON is located via repo_paths (not Path(__file__))."""

from __future__ import annotations

from pathlib import Path

import pytest

import backend.periscopex.taxonomy as taxonomy
from backend.periscopex.taxonomy import (
    SIMPLE_TYPES,
    add_subtype,
    get_subtype,
    list_subtypes,
    load_subtypes,
    type_for_ref,
    validate_subtype,
)
from backend.repo_paths import taxonomy_dir


def test_taxonomy_module_is_src():
    path = Path(taxonomy.__file__).resolve()
    assert path.parts[-5:] == ("periscope", "src", "backend", "periscopex", "taxonomy.py")
    text = path.read_text(encoding="utf-8")
    assert "from backend.repo_paths import taxonomy_dir" in text
    assert "TAXONOMY_DIR = taxonomy_dir()" in text
    assert "Native Periscope overlay" not in text


def test_taxonomy_dir_points_at_dependency_json():
    d = taxonomy_dir()
    assert d.parts[-2:] == ("dependency", "taxonomy")
    assert (d / "ic.json").is_file()
    assert taxonomy.TAXONOMY_DIR == d
    assert not (Path(taxonomy.__file__).resolve().parent.parent.parent / "taxonomy" / "ic.json").is_file()


def test_emmaforo_ref_prefixes():
    """Emmaforo-style designators: MCU, USB, LEDs, passives — not layout primitives."""
    assert type_for_ref("U1") == "ic"
    assert type_for_ref("U3") == "ic"
    assert type_for_ref("LED1") == "discrete"
    assert type_for_ref("L1") == "passive"
    assert type_for_ref("C12") == "passive"
    assert type_for_ref("R10") == "passive"
    assert type_for_ref("J1") == "connector"
    assert type_for_ref("Y1") == "crystal"
    assert type_for_ref("X1") == "crystal"
    assert type_for_ref("TP1") == "test_point"
    assert type_for_ref("FB1") == "passive"
    assert type_for_ref("SW1") == "switch"


def test_emmaforo_ic_json_has_mcu_and_interface_keys():
    ic = load_subtypes("ic")
    assert "ic.mcu" in ic
    assert ic["ic.mcu"]["example_mpn"] == "MSPM0G3507SPTR"
    assert get_subtype("ic.interface.usb_uart_bridge") is not None
    assert "ic.mcu" in list_subtypes("ic")


def test_validate_subtype_and_unknown_top():
    assert validate_subtype("IC.MCU") == "ic.mcu"
    assert validate_subtype("passive.resistor") == "passive.resistor"
    with pytest.raises(ValueError, match="Unknown top-level"):
        validate_subtype("notatype.foo")
    with pytest.raises(ValueError, match="Invalid component_subtype"):
        validate_subtype("ic..mcu")
    assert type_for_ref("9") is None
    assert type_for_ref("") is None
    assert type_for_ref("RN4") is None  # RN is not a taxonomy prefix (graph still maps RN→resistor)


def test_layout_primitives_are_not_taxonomy_types():
    """Pad≠Via≠Track≠Zone: layout kinds are not component_subtype tops."""
    for bogus in ("pad.smd", "via.through", "track.microstrip", "zone.copper"):
        with pytest.raises(ValueError, match="Unknown top-level"):
            validate_subtype(bogus)
    assert type_for_ref("VIA1") is None
    assert type_for_ref("PAD1") is None


def test_simple_types_exclude_ic_and_passive():
    assert "ic" not in SIMPLE_TYPES
    assert "passive" not in SIMPLE_TYPES
    assert "connector" in SIMPLE_TYPES


def test_add_subtype_writes_only_given_directory(tmp_path: Path):
    add_subtype("ic.sensor.humidity", "Humidity sensor IC", directory=tmp_path)
    written = tmp_path / "ic.json"
    assert written.is_file()
    assert "ic.sensor.humidity" in written.read_text(encoding="utf-8")
    live = (taxonomy_dir() / "ic.json").read_text(encoding="utf-8")
    assert "ic.sensor.humidity" not in live