from __future__ import annotations

import os
from urllib.parse import parse_qs, urlparse


def _set_google_env() -> None:
    os.environ["GOOGLE_CLIENT_ID"] = "test-google-client"
    os.environ["GOOGLE_CLIENT_SECRET"] = "test-google-secret"
    os.environ["FRONTEND_BASE_URL"] = "http://127.0.0.1:3000"
    os.environ["GOOGLE_OAUTH_REDIRECT_URI"] = "http://testserver/auth/google/callback"

    from app.core.config import get_settings

    get_settings.cache_clear()


def _clear_google_env() -> None:
    for key in (
        "GOOGLE_CLIENT_ID",
        "GOOGLE_CLIENT_SECRET",
        "FRONTEND_BASE_URL",
        "GOOGLE_OAUTH_REDIRECT_URI",
    ):
        os.environ.pop(key, None)

    from app.core.config import get_settings

    get_settings.cache_clear()


def _fragment_params(location: str) -> dict[str, str]:
    fragment = urlparse(location).fragment
    parsed = parse_qs(fragment)
    return {key: values[0] for key, values in parsed.items()}


def test_google_start_redirects_to_frontend_error_without_oauth_credentials(auth_client):
    os.environ["GOOGLE_CLIENT_ID"] = ""
    os.environ["GOOGLE_CLIENT_SECRET"] = ""

    from app.core.config import get_settings

    get_settings.cache_clear()
    try:
        response = auth_client.get("/auth/google/start", follow_redirects=False)
    finally:
        _clear_google_env()

    assert response.status_code == 302
    params = _fragment_params(response.headers["location"])
    assert "not ready" in params["error"].lower()


def test_google_callback_creates_user_and_returns_frontend_session(auth_client, monkeypatch):
    _set_google_env()

    from app.routes import auth as auth_routes

    monkeypatch.setattr(
        auth_routes,
        "_post_google_token",
        lambda payload: {"access_token": "google-access-token"},
    )
    monkeypatch.setattr(
        auth_routes,
        "_fetch_google_profile",
        lambda access_token: {
            "email": "google.student@example.com",
            "email_verified": True,
            "name": "Google Student",
        },
    )

    try:
        nonce = "test-google-state-nonce"
        state = auth_routes._create_google_state(
            next_path="/dashboard", invite_code=None, nonce=nonce
        )
        response = auth_client.get(
            f"/auth/google/callback?code=test-code&state={state}",
            cookies={auth_routes.GOOGLE_STATE_COOKIE: nonce},
            follow_redirects=False,
        )

        assert response.status_code == 302
        location = response.headers["location"]
        assert location.startswith("http://127.0.0.1:3000/auth/google/callback#")
        params = _fragment_params(location)
        assert params["access_token"]
        assert params["token_type"] == "bearer"
        assert params["next"] == "/dashboard"
        assert "google.student@example.com" in params["user"]
    finally:
        _clear_google_env()


def test_google_callback_respects_beta_invite_gate(auth_client, monkeypatch):
    _set_google_env()
    os.environ["BETA_ACCESS_ENABLED"] = "true"
    os.environ["BETA_INVITE_CODE"] = "DOCDOE-BETA-2026"

    from app.core.config import get_settings
    from app.routes import auth as auth_routes

    get_settings.cache_clear()
    monkeypatch.setattr(
        auth_routes,
        "_post_google_token",
        lambda payload: {"access_token": "google-access-token"},
    )
    monkeypatch.setattr(
        auth_routes,
        "_fetch_google_profile",
        lambda access_token: {
            "email": "invite-needed@example.com",
            "email_verified": True,
            "name": "Invite Needed",
        },
    )

    try:
        nonce = "test-google-state-nonce"
        state = auth_routes._create_google_state(
            next_path="/onboarding", invite_code=None, nonce=nonce
        )
        response = auth_client.get(
            f"/auth/google/callback?code=test-code&state={state}",
            cookies={auth_routes.GOOGLE_STATE_COOKIE: nonce},
            follow_redirects=False,
        )

        assert response.status_code == 302
        params = _fragment_params(response.headers["location"])
        assert "invite" in params["error"].lower()
        assert params["next"] == "/onboarding"
    finally:
        os.environ["BETA_ACCESS_ENABLED"] = "false"
        os.environ.pop("BETA_INVITE_CODE", None)
        _clear_google_env()


def test_google_callback_rejects_state_from_another_browser(auth_client, monkeypatch):
    _set_google_env()

    from app.routes import auth as auth_routes

    monkeypatch.setattr(
        auth_routes,
        "_post_google_token",
        lambda payload: (_ for _ in ()).throw(AssertionError("token exchange must not run")),
    )
    try:
        state = auth_routes._create_google_state(
            next_path="/dashboard", invite_code=None, nonce="browser-a"
        )
        response = auth_client.get(
            f"/auth/google/callback?code=test-code&state={state}",
            cookies={auth_routes.GOOGLE_STATE_COOKIE: "browser-b"},
            follow_redirects=False,
        )

        assert response.status_code == 302
        params = _fragment_params(response.headers["location"])
        assert "expired" in params["error"].lower()
    finally:
        _clear_google_env()