"""Ferrite beads: recover Z from evidence; never invent; never abort ingest."""

from __future__ import annotations

import json
from pathlib import Path

import pytest
from pydantic import ValidationError

from backend.periscopex.ferrite_z import recover_bead_specs, z_from_datasheet_text
from backend.periscopex.graph import _load_component_models
from backend.periscopex.models import ComponentModel, InductorSpecs, SimpleComponentSpecs
from backend.periscopex.resolve_passives import simple_to_typed_passive_specs


def test_ferrite_bead_quoted_ohm_fills_z_not_henries():
    specs = InductorSpecs(
        component_subtype="passive.ferrite_bead",
        value_formatted="120 ohm @ 100 MHz",
        current_rating_a="3A",
        dcr_ohms=0.03,
    )
    assert specs.impedance_ohm == 120.0
    assert specs.value_henries is None
    model = ComponentModel(mpn="BLM21PG121SN1D", specs=specs)
    assert model.specs.impedance_ohm == 120.0


def test_ferrite_bead_live_payload_fills_z_from_formatted():
    model = ComponentModel.model_validate({
        "mpn": "BLM21PG121SN1D",
        "specs": {
            "specs_type": "inductor",
            "component_subtype": "passive.ferrite_bead",
            "value_henries": 120.0,
            "value_formatted": "120 ohm @ 100 MHz",
            "tolerance": None,
            "package": "0805",
            "current_rating_a": "3A",
            "dcr_ohms": 0.03,
        },
    })
    assert model.specs.impedance_ohm == 120.0
    assert model.specs.value_henries is None
    assert model.specs.current_rating_a == "3A"
    assert model.specs.dcr_ohms == 0.03


def test_ferrite_bead_with_impedance_ohm_still_ok():
    specs = InductorSpecs(
        component_subtype="passive.ferrite_bead",
        value_formatted="120 ohm @ 100 MHz",
        impedance_ohm=120.0,
        current_rating_a="3A",
        dcr_ohms=0.03,
    )
    assert specs.impedance_ohm == 120.0
    assert specs.value_henries is None


def test_inductor_still_requires_value_henries():
    with pytest.raises(ValidationError, match="inductor requires value_henries"):
        InductorSpecs(
            component_subtype="passive.inductor",
            value_formatted="15nH",
        )


def test_load_models_bead_without_z_does_not_raise(tmp_path: Path):
    payload = {
        "mpn": "BLM21PG121SN1D",
        "specs": {
            "specs_type": "inductor",
            "component_subtype": "passive.ferrite_bead",
            "value_formatted": "FB",
            "current_rating_a": "3A",
            "dcr_ohms": 0.03,
        },
    }
    (tmp_path / "BLM21PG121SN1D.json").write_text(json.dumps(payload) + "\n")
    loaded = _load_component_models(tmp_path)
    assert "BLM21PG121SN1D" in loaded
    assert loaded["BLM21PG121SN1D"].impedance_ohm is None


def test_load_models_skips_inductor_missing_henries(tmp_path: Path):
    bad = {
        "mpn": "LQW-BAD",
        "specs": {
            "specs_type": "inductor",
            "component_subtype": "passive.inductor",
            "value_formatted": "x",
        },
    }
    (tmp_path / "LQW-BAD.json").write_text(json.dumps(bad) + "\n")
    loaded = _load_component_models(tmp_path)
    assert loaded == {}


def test_simple_to_typed_bead_without_z():
    simple = SimpleComponentSpecs(
        specs_type="passive",
        component_subtype="passive.ferrite_bead",
        values={"current_rating_a": "3A", "dcr_ohms": 0.03},
    )
    specs = simple_to_typed_passive_specs(simple)
    assert specs.specs_type == "inductor"
    assert specs.impedance_ohm is None
    assert specs.dcr_ohms == 0.03


def test_bead_mpn_datasheet_text_fills_z():
    text = (
        "BLM21PG121SN1D chip ferrite bead\n"
        "Impedance (at 100MHz / 20°C) 120 ohm\n"
        "Rated current 3A\n"
        "DC resistance 0.03 ohm\n"
    )
    hit = z_from_datasheet_text(text)
    assert hit is not None
    z, formatted = hit
    assert z == 120.0
    assert "100" in formatted
    assert "datasheet" in formatted
    specs = InductorSpecs(
        component_subtype="passive.ferrite_bead",
        value_formatted="FB",
        current_rating_a="3A",
        dcr_ohms=0.03,
    )
    filled = recover_bead_specs(specs, extra_text=text)
    assert filled.impedance_ohm == 120.0
    assert filled.value_henries is None


def test_bead_mpn_datasheet_without_z_does_not_invent():
    text = "BLM21PG121SN1D\nRated current 3 A\nDCR 0.03 ohm max\nPackage 0805"
    assert z_from_datasheet_text(text) is None
    specs = InductorSpecs(
        component_subtype="passive.ferrite_bead",
        value_formatted="FB",
        current_rating_a="3A",
        dcr_ohms=0.03,
    )
    filled = recover_bead_specs(specs, extra_text=text)
    assert filled.impedance_ohm is None
    model = ComponentModel(mpn="BLM21PG121SN1D", specs=filled)
    assert model.specs.impedance_ohm is None