from datetime import datetime

import pytest
from fastapi.testclient import TestClient

from app.main import app


client = TestClient(app)


def test_health_ok():
    response = client.get("/health")

    assert response.status_code == 200

    data = response.json()
    assert data["status"] == "ok"
    assert "server_time" in data

    # Validate ISO-8601 format (basic check via fromisoformat)
    parsed = datetime.fromisoformat(data["server_time"])
    assert isinstance(parsed, datetime)


def test_health_idempotent_time_increases():
    response1 = client.get("/health")
    response2 = client.get("/health")

    assert response1.status_code == 200
    assert response2.status_code == 200

    data1 = response1.json()
    data2 = response2.json()

    t1 = datetime.fromisoformat(data1["server_time"])
    t2 = datetime.fromisoformat(data2["server_time"])

    assert t2 >= t1


def test_health_method_not_allowed():
    response = client.post("/health")

    assert response.status_code == 405