import pytest
from rest_framework.test import APIClient

pytestmark = pytest.mark.django_db

VALID_USER = {
    'name': 'Test User',
    'email': 'test@example.com',
    'password': 'TestPass123!',
    'password_confirm': 'TestPass123!'
}

REGISTER_URL = '/api/auth/register/'
LOGIN_URL = '/api/auth/login/'
LOGOUT_URL = '/api/auth/logout/'
ME_URL = '/api/auth/me/'


@pytest.fixture
def api_client():
    return APIClient()


@pytest.fixture
def user_data():
    return VALID_USER.copy()


@pytest.fixture
def registered_user(api_client, user_data):
    """Register a user and return the response data."""
    response = api_client.post(REGISTER_URL, data=user_data, format='json')
    return response.data


class TestRegistration:
    def test_valid_registration(self, api_client, user_data):
        """TC-01: Valid registration returns 201 with tokens."""
        response = api_client.post(REGISTER_URL, data=user_data, format='json')
        assert response.status_code == 201
        assert 'access' in response.data
        assert 'refresh' in response.data
        assert 'user' in response.data
        assert response.data['user']['email'] == user_data['email']

    def test_duplicate_email(self, api_client, user_data):
        """TC-02: Duplicate email returns 400."""
        api_client.post(REGISTER_URL, data=user_data, format='json')
        response = api_client.post(REGISTER_URL, data=user_data, format='json')
        assert response.status_code == 400

    def test_password_mismatch(self, api_client, user_data):
        """Password mismatch returns 400."""
        user_data['password_confirm'] = 'DifferentPassword!'
        response = api_client.post(REGISTER_URL, data=user_data, format='json')
        assert response.status_code == 400

    def test_missing_fields(self, api_client):
        """Missing required fields returns 400."""
        response = api_client.post(REGISTER_URL, data={'email': 'x@x.com'}, format='json')
        assert response.status_code == 400


class TestLogin:
    def test_valid_login(self, api_client, user_data, registered_user):
        """TC-03: Valid login returns 200 with tokens."""
        login_data = {'email': user_data['email'], 'password': user_data['password']}
        response = api_client.post(LOGIN_URL, data=login_data, format='json')
        assert response.status_code == 200
        assert 'access' in response.data
        assert 'refresh' in response.data

    def test_invalid_credentials(self, api_client, user_data, registered_user):
        """TC-04: Wrong password returns 400."""
        login_data = {'email': user_data['email'], 'password': 'WrongPassword!'}
        response = api_client.post(LOGIN_URL, data=login_data, format='json')
        assert response.status_code == 400


class TestMe:
    def test_me_without_token(self, api_client):
        """GET /me/ without token returns 401."""
        response = api_client.get(ME_URL)
        assert response.status_code == 401

    def test_get_me(self, api_client, user_data, registered_user):
        """Authenticated GET /me/ returns user data."""
        access_token = registered_user['access']
        api_client.credentials(HTTP_AUTHORIZATION='Bearer ' + access_token)
        response = api_client.get(ME_URL)
        assert response.status_code == 200
        assert response.data['email'] == user_data['email']


class TestLoginThrottle:
    def test_login_rate_limit_blocks_after_threshold(
        self, api_client, user_data, registered_user,
    ):
        """Login endpoint is throttled at 10/minute — verify the 11th
        attempt is rejected with 429, regardless of credentials."""
        bad = {'email': user_data['email'], 'password': 'nope'}
        # Burn through the limit with invalid credentials (400 per attempt).
        for _ in range(10):
            r = api_client.post(LOGIN_URL, data=bad, format='json')
            assert r.status_code in (400, 401)
        # 11th must be throttled.
        r = api_client.post(LOGIN_URL, data=bad, format='json')
        assert r.status_code == 429


class TestLogout:
    def test_logout(self, api_client, user_data, registered_user):
        """Logout blacklists refresh token, returns 204."""
        access_token = registered_user['access']
        refresh_token = registered_user['refresh']

        api_client.credentials(HTTP_AUTHORIZATION='Bearer ' + access_token)
        response = api_client.post(
            LOGOUT_URL,
            data={'refresh_token': refresh_token},
            format='json'
        )
        assert response.status_code == 204


class TestRegistrationRace:
    def test_concurrent_email_race_returns_400(self, api_client, user_data):
        """F2: a concurrent case-variant registration can bypass the
        case-insensitive validate_email check; the DB unique index then raises
        IntegrityError. The view must surface a clean 400 keyed on `email`,
        not an unhandled 500."""
        from unittest.mock import patch
        from django.db import IntegrityError
        with patch(
            'apps.accounts.serializers.RegisterSerializer.save',
            side_effect=IntegrityError,
        ):
            response = api_client.post(REGISTER_URL, data=user_data, format='json')
        assert response.status_code == 400
        assert 'email' in response.data