intelligence-router/tests/test_router_model_detection.py

"""Tests for automatic model detection — Issue #4.

Router extracts model from chat body, queries sidecar, triggers switch on mismatch.
"""
import asyncio
import pytest
from unittest.mock import patch
from httpx import Response, ASGITransport, AsyncClient

from main import app as router_app

SIDECAR_URL = "http://localhost:8081"
MAIN_PC_URL = "http://localhost:8080"


@pytest.fixture(autouse=True)
def setup():
    """Setup test environment."""
    import main
    main._circuit_open = False
    main._recovery_attempts = 0
    with patch("main.SIDECAR_URL", SIDECAR_URL), \
         patch("main.MAIN_PC_BASE", MAIN_PC_URL), \
         patch("main.FALLBACK_SLM_URL", "http://localhost:9999"), \
         patch("main.OPENROUTER_API_KEY", ""):
        yield


def test_active_model_match_routes_directly():
    """Matching active model → routes to Main PC without switch."""
    import respx

    async def run_test():
        with respx.mock:
            respx.get(f"{SIDECAR_URL}/models/status").mock(
                return_value=Response(200, json={"active_profile": "qwen-3-8b", "llama_server_running": True})
            )
            respx.post(f"{MAIN_PC_URL}/v1/chat/completions").mock(
                return_value=Response(200, json={"choices": [{"message": {"content": "Hello"}}]})
            )
            transport = ASGITransport(app=router_app)
            async with AsyncClient(transport=transport, base_url="http://test") as ac:
                resp = await ac.post(
                    "/v1/chat/completions",
                    json={"model": "qwen-3-8b", "messages": [{"role": "user", "content": "hi"}]},
                )
            assert resp.status_code == 200
            switch_calls = [r for r in respx.calls if "switch" in r[0].url.path]
            assert len(switch_calls) == 0

    asyncio.run(run_test())


def test_mismatch_triggers_switch():
    """Mismatching model → triggers switch via sidecar."""
    import respx

    async def run_test():
        with respx.mock:
            respx.get(f"{SIDECAR_URL}/models/status").mock(
                return_value=Response(200, json={"active_profile": "llama-4-maverick", "llama_server_running": True})
            )
            respx.post(f"{SIDECAR_URL}/models/switch").mock(
                return_value=Response(200, json={"status": "ready", "active_profile": "qwen-3-8b"})
            )
            respx.post(f"{MAIN_PC_URL}/v1/chat/completions").mock(
                return_value=Response(200, json={"choices": [{"message": {"content": "Hello"}}]})
            )
            transport = ASGITransport(app=router_app)
            async with AsyncClient(transport=transport, base_url="http://test") as ac:
                resp = await ac.post(
                    "/v1/chat/completions",
                    json={"model": "qwen-3-8b", "messages": [{"role": "user", "content": "hi"}]},
                )
            assert resp.status_code == 200

    asyncio.run(run_test())


def test_no_active_model_triggers_cold_start():
    """No active model → triggers cold start switch."""
    import respx

    async def run_test():
        with respx.mock:
            respx.get(f"{SIDECAR_URL}/models/status").mock(
                return_value=Response(200, json={"active_profile": None, "llama_server_running": False})
            )
            respx.post(f"{SIDECAR_URL}/models/switch").mock(
                return_value=Response(200, json={"status": "ready", "active_profile": "qwen-3-8b"})
            )
            respx.post(f"{MAIN_PC_URL}/v1/chat/completions").mock(
                return_value=Response(200, json={"choices": [{"message": {"content": "Hello"}}]})
            )
            transport = ASGITransport(app=router_app)
            async with AsyncClient(transport=transport, base_url="http://test") as ac:
                resp = await ac.post(
                    "/v1/chat/completions",
                    json={"model": "qwen-3-8b", "messages": [{"role": "user", "content": "hi"}]},
                )
            assert resp.status_code == 200

    asyncio.run(run_test())