from app.discovery.enums import MatchStatus
from app.discovery.identity import IdentitySignals, decide_identity, spec_fingerprint


def _sig(**overrides) -> IdentitySignals:
    base = IdentitySignals(
        source_external_id="gh-1",
        gtin_ean="4000000000001",
        manufacturer_sku="EM13-32",
        source_url="https://geizhals.de/a.html",
        title="Example Mobile 13",
        manufacturer="Example",
        model="Mobile 13",
        fingerprint=spec_fingerprint({"manufacturer": "Example", "model": "Mobile 13", "ram": 32}),
    )
    return IdentitySignals(**{**base.__dict__, **overrides})


def test_sku_and_ean_and_url_match():
    known = [("a", _sig())]
    assert decide_identity(_sig(), known).reason == "source_external_id"
    assert decide_identity(_sig(source_external_id="other"), known).reason == "gtin_ean"
    assert decide_identity(_sig(source_external_id="other", gtin_ean="x"), known).reason == "manufacturer_sku"
    assert decide_identity(
        _sig(source_external_id="other", gtin_ean="x", manufacturer_sku="y"),
        known,
    ).reason == "source_url"


def test_title_plus_fingerprint_matches_stable_specs():
    known = [("a", _sig(source_external_id=None, gtin_ean=None, manufacturer_sku=None, source_url=None))]
    incoming = _sig(
        source_external_id=None,
        gtin_ean=None,
        manufacturer_sku=None,
        source_url=None,
        title="Example   Mobile 13",
    )
    decision = decide_identity(incoming, known)
    assert decision.match_status == MatchStatus.MATCHED
    assert decision.reason == "title+fingerprint"


def test_title_only_is_uncertain_and_never_merges():
    known = [("a", _sig(source_external_id=None, gtin_ean=None, manufacturer_sku=None, source_url=None))]
    incoming = _sig(
        source_external_id=None,
        gtin_ean=None,
        manufacturer_sku=None,
        source_url=None,
        fingerprint="different",
        manufacturer="Other",
        model="Other",
    )
    decision = decide_identity(incoming, known)
    assert decision.match_status == MatchStatus.MATCH_UNCERTAIN
    assert decision.existing_id is None
    assert decision.reason == "title only"


def test_fingerprint_uses_observed_keys_only():
    left = spec_fingerprint({"capacity_l": 2, "color": "black"})
    right = spec_fingerprint({"capacity_l": 5, "color": "black"})
    assert left != right
    assert "capacity_l=2" in left
    assert "ram_gb" not in left
    assert spec_fingerprint({"title": "ignored", "html": "<b>", "noise": 1}) == "noise=1"


def test_similar_names_do_not_merge():
    known = [("a", _sig(source_external_id=None, gtin_ean=None, manufacturer_sku=None, source_url=None))]
    incoming = _sig(
        source_external_id=None,
        gtin_ean=None,
        manufacturer_sku=None,
        source_url=None,
        title="Example Mobile 14",
        fingerprint="other",
        manufacturer="Example",
        model="Mobile 14",
    )
    decision = decide_identity(incoming, known)
    assert decision.match_status == MatchStatus.NEW_REFERENCE