"""v0.2 destination transforms (spec v0.2 section 12.1)."""
import pytest

from mas_conformance import statute_document
from mas_core.generator import DESTINATION_PROFILES, CannotExpress, for_destination
from mas_core.statute import build_statute


def statute(resource=True, interaction=True, id_case="insensitive", version="0.2"):
    doc = statute_document("valid-great-service.json")
    doc["mas_version"] = version
    if version == "0.2":
        doc["alternate_syntax"] = {"resource": resource, "interaction": interaction}
        doc["equivalence"]["resource_id_case"] = id_case
    return build_statute(doc, "great-service.example")


V2 = statute()
IONOS = DESTINATION_PROFILES["ionos-forward"]


def test_canonical_when_nothing_is_needed():
    r = for_destination("ticket=GS-1+comments", V2, ())
    assert (r.local_part, r.applied) == ("ticket=GS-1+comments", ())


def test_ionos_forward_profile():
    # the MAS-WP-0003 case: IONOS refuses '=' and forces lower case
    r = for_destination("ticket=GS-85QJ8WC09P+comments", V2, IONOS)
    assert r.local_part == "ticket--gs-85qj8wc09p+comments"
    assert r.applied == ("resource-alternate", "lowercase")


def test_transforms_apply_only_where_they_change_something():
    assert for_destination("support", V2, IONOS).applied == ()
    assert for_destination("ticket=gs-1", V2, IONOS).applied == ("resource-alternate",)


def test_interaction_alternate():
    assert for_destination("ticket!callback", V2, ("interaction-alternate",)).local_part == "ticket---callback"


@pytest.mark.parametrize("st, code", [
    (statute(resource=False), "transform-not-permitted"),     # no '--' switch
    (statute(version="0.1"), "transform-not-permitted"),      # v0.1 statute
    (statute(id_case="exact"), "would-be-misread"),           # lower-casing changes the id
])
def test_refuses_what_the_namespace_would_misread(st, code):
    with pytest.raises(CannotExpress) as e:
        for_destination("ticket=GS-1", st, IONOS)
    assert e.value.code == code


def test_refuses_id_containing_equals():
    with pytest.raises(CannotExpress) as e:
        for_destination("ticket=RE=2026-4711", V2, ("resource-alternate",))
    assert e.value.code == "cannot-express"


def test_refuses_case_change_in_facet():
    with pytest.raises(CannotExpress) as e:
        for_destination("ticket=gs-1+Comments", V2, ("lowercase",))
    assert e.value.code == "would-be-misread"


def test_length_is_checked_after_transforms():
    lp = "ticket=" + "a" * 57          # 64 octets canonical, 65 with '--'
    assert len(lp) == 64
    with pytest.raises(CannotExpress) as e:
        for_destination(lp, V2, ("resource-alternate",))
    assert e.value.code == "too-long"


def test_lossy_transforms_need_explicit_permission():
    with pytest.raises(CannotExpress):
        for_destination("ticket=gs-1+comments", V2, ("drop-facet",))
    r = for_destination("ticket!callback", V2, ("drop-interaction",), allow_lossy=True)
    assert r.local_part == "ticket" and r.warnings