tests/test_ai_provider_fallback.py

"""Tests for AI provider fallback tracking and is_fallback signal."""

from __future__ import annotations

import os
import sys
from pathlib import Path
from unittest.mock import MagicMock, patch

BACKEND_DIR = Path(__file__).resolve().parents[1]
if str(BACKEND_DIR) not in sys.path:
    sys.path.insert(0, str(BACKEND_DIR))

os.environ.setdefault("AI_PROVIDER", "mock")
os.environ.setdefault("AUTH_ENABLED", "false")

from app.core.config import get_settings

get_settings.cache_clear()

from app.services.ai_provider import (
    MockAIProvider,
    get_ai_provider,
)


def test_mock_provider_not_fallback_when_configured_as_mock():
    os.environ["AI_PROVIDER"] = "mock"
    get_settings.cache_clear()
    provider = get_ai_provider()
    assert isinstance(provider, MockAIProvider)
    assert provider.is_fallback is False
    assert provider.fallback_reason is None


def test_mock_provider_is_fallback_when_openrouter_key_missing():
    """When AI_PROVIDER=openrouter but key is absent, get_ai_provider must
    return a MockAIProvider with is_fallback=True.

    We mock get_settings so the .env file on disk (which may have a real key)
    does not interfere with the test.
    """
    mock_settings = MagicMock()
    mock_settings.ai_provider = "openrouter"
    mock_settings.openrouter_api_key = None

    with patch("app.services.ai_provider.get_settings", return_value=mock_settings):
        provider = get_ai_provider()

    assert isinstance(provider, MockAIProvider)
    assert provider.is_fallback is True
    assert "not configured" in (provider.fallback_reason or "").lower()


def test_mock_provider_model_name():
    os.environ["AI_PROVIDER"] = "mock"
    get_settings.cache_clear()
    provider = get_ai_provider()
    assert "mock" in provider.model_name.lower()


def test_health_ai_endpoint_requires_admin(client):
    """Provider diagnostics must not be exposed to anonymous callers."""
    resp = client.get("/health/ai")
    assert resp.status_code == 403


def test_health_ai_endpoint_returns_provider_status_for_admin(client):
    """The admin-only diagnostic still reports the configured provider."""
    from app.core.admin_auth import require_admin

    client.app.dependency_overrides[require_admin] = lambda: None
    try:
        resp = client.get("/health/ai")
    finally:
        client.app.dependency_overrides.pop(require_admin, None)

    assert resp.status_code == 200
    data = resp.json()
    assert data["status"] in ("ready", "demo", "misconfigured")
    assert "provider" in data
    assert "can_generate" in data


def test_ask_response_has_is_fallback(client):
    resp = client.post("/ask", json={"question": "What is photosynthesis?"})
    assert resp.status_code == 200
    data = resp.json()
    assert "is_fallback" in data
    assert isinstance(data["is_fallback"], bool)
    assert "model_used" in data


def test_studio_notes_response_has_is_fallback(client):
    resp = client.post(
        "/generate/notes",
        json={"topic": "Photosynthesis", "language_preference": "English"},
    )
    assert resp.status_code == 200
    data = resp.json()
    assert "is_fallback" in data
    assert isinstance(data["is_fallback"], bool)
    assert "model_used" in data


def test_studio_exam_answer_response_has_is_fallback(client):
    resp = client.post(
        "/generate/exam-answer",
        json={"topic": "Photosynthesis", "language_preference": "English"},
    )
    assert resp.status_code == 200
    data = resp.json()
    assert "is_fallback" in data
    assert isinstance(data["is_fallback"], bool)


def test_mock_provider_generates_without_fallback():
    os.environ["AI_PROVIDER"] = "mock"
    get_settings.cache_clear()
    provider = get_ai_provider()
    output = provider.generate_simple_explanation(
        context="Photosynthesis is the process by which plants make food using sunlight.",
        language="English",
    )
    assert provider.is_fallback is False
    assert "simple_meaning" in output


def test_unknown_provider_falls_back_to_mock():
    mock_settings = MagicMock()
    mock_settings.ai_provider = "nonexistent-provider"
    mock_settings.sarvam_api_key = None
    mock_settings.openrouter_api_key = None
    mock_settings.gemini_api_key = None
    mock_settings.environment = "development"
    mock_settings.ai_fallback_to_mock = True

    with patch("app.services.ai_provider.get_settings", return_value=mock_settings):
        provider = get_ai_provider()
    assert isinstance(provider, MockAIProvider)