import importlib
import os

import pytest
from fastapi.testclient import TestClient


@pytest.fixture
def client(tmp_path):
    os.environ["DB_PATH"] = str(tmp_path / "test.db")
    os.environ["SYNC_TOKEN"] = "geheim"
    from app import config, db, main
    importlib.reload(config)
    importlib.reload(db)
    importlib.reload(main)
    with TestClient(main.app) as c:
        yield c


AUTH = {"Authorization": "Bearer geheim"}


def sync(client, since=0, **collections):
    body = {"since": since, **collections}
    r = client.post("/api/sync", json=body, headers=AUTH)
    assert r.status_code == 200, r.text
    return r.json()


def test_health_ohne_token(client):
    assert client.get("/api/health").json() == {"ok": True}


def test_falscher_token(client):
    assert client.post("/api/sync", json={}).status_code == 401
    assert client.post("/api/sync", json={}, headers={"Authorization": "Bearer falsch"}).status_code == 401
    assert client.get("/api/events").status_code == 401


def test_push_und_pull(client):
    a = sync(client, events=[{"id": "e1", "updated": "2026-09-19T10:00:00.000Z", "title": "Zahnarzt"}])
    assert a["cursor"] == 1
    assert [e["id"] for e in a["events"]] == ["e1"]

    # Anderes Gerät ohne Stand bekommt alles
    b = sync(client)
    assert [e["title"] for e in b["events"]] == ["Zahnarzt"]
    assert b["cursor"] == 1

    # Mit aktuellem Stand kommt nichts Neues
    c = sync(client, since=1)
    assert c["events"] == [] and c["cursor"] == 1


def test_neuester_gewinnt(client):
    sync(client, todos=[{"id": "t1", "updated": "2026-09-19T10:00:00.000Z", "title": "alt"}])
    sync(client, todos=[{"id": "t1", "updated": "2026-09-19T09:00:00.000Z", "title": "älter"}])
    assert client.get("/api/todos", headers=AUTH).json()[0]["title"] == "alt"
    r = sync(client, since=0, todos=[{"id": "t1", "updated": "2026-09-19T11:00:00.000Z", "title": "neu"}])
    assert r["todos"][0]["title"] == "neu"
    assert r["cursor"] == 2


def test_abgelehnte_aenderung_bekommt_serverstand(client):
    sync(client, todos=[{"id": "t1", "updated": "2026-09-19T10:00:00.000Z", "title": "server"}])
    r = sync(client, since=1, todos=[{"id": "t1", "updated": "2026-09-19T09:00:00.000Z", "title": "client"}])
    assert [t["title"] for t in r["todos"]] == ["server"]
    assert r["cursor"] == 1


def test_tombstone(client):
    sync(client, notes=[{"id": "Plan.md", "updated": "2026-09-19T10:00:00.000Z", "content": "x"}])
    r = sync(client, since=1, notes=[{"id": "Plan.md", "updated": "2026-09-19T10:05:00.000Z", "deleted": True}])
    assert r["notes"][0]["deleted"] is True
    assert client.get("/api/notes", headers=AUTH).json() == []
    # Ein verspäteter älterer Stand belebt die Notiz nicht wieder
    sync(client, notes=[{"id": "Plan.md", "updated": "2026-09-19T10:01:00.000Z", "content": "y"}])
    assert client.get("/api/notes", headers=AUTH).json() == []


def test_seit_cursor_liefert_nur_neues(client):
    sync(client, events=[{"id": "e1", "updated": "2026-09-19T10:00:00.000Z", "title": "a"}])
    sync(client, events=[{"id": "e2", "updated": "2026-09-19T10:00:00.000Z", "title": "b"}])
    r = sync(client, since=1)
    assert [e["id"] for e in r["events"]] == ["e2"]