"""Duplicate relationships are rejected (no double-linking)."""

from tests.conftest import auth, register


async def _setup(client, email):
    h = auth(await register(client, email))
    tid = (await client.post("/api/v1/trees", json={"name": "T"}, headers=h)).json()["id"]

    async def person(given):
        return (
            await client.post(f"/api/v1/trees/{tid}/persons", json={"given": given}, headers=h)
        ).json()["id"]

    return h, tid, person


async def test_duplicate_parent_child_rejected(client):
    h, tid, person = await _setup(client, "dup-pc@example.com")
    karl = await person("Karl")
    kid = await person("Kid")
    body = {"type": "parent_child", "person_from_id": karl, "person_to_id": kid}

    first = await client.post(f"/api/v1/trees/{tid}/relationships", json=body, headers=h)
    assert first.status_code == 201
    dup = await client.post(f"/api/v1/trees/{tid}/relationships", json=body, headers=h)
    assert dup.status_code == 409


async def test_duplicate_partnership_either_direction_rejected(client):
    h, tid, person = await _setup(client, "dup-sp@example.com")
    a = await person("A")
    b = await person("B")

    first = await client.post(
        f"/api/v1/trees/{tid}/relationships",
        json={"type": "partnership", "person_from_id": a, "person_to_id": b},
        headers=h,
    )
    assert first.status_code == 201
    # Same couple, reversed order — still a duplicate.
    dup = await client.post(
        f"/api/v1/trees/{tid}/relationships",
        json={"type": "partnership", "person_from_id": b, "person_to_id": a},
        headers=h,
    )
    assert dup.status_code == 409


async def test_reverse_parent_child_is_allowed(client):
    """A->B as parent_child shouldn't block B->A (different meaning)."""
    h, tid, person = await _setup(client, "dup-rev@example.com")
    a = await person("A")
    b = await person("B")
    r1 = await client.post(
        f"/api/v1/trees/{tid}/relationships",
        json={"type": "parent_child", "person_from_id": a, "person_to_id": b},
        headers=h,
    )
    r2 = await client.post(
        f"/api/v1/trees/{tid}/relationships",
        json={"type": "parent_child", "person_from_id": b, "person_to_id": a},
        headers=h,
    )
    assert r1.status_code == 201 and r2.status_code == 201