"""Judge backend selection + transformers-fallback — no GPU, no downloads."""
import importlib

import formscout.config as config
from formscout.serving import get_vlm_client
from formscout.serving.llama_cpp import LlamaCppClient


def _reload_config(monkeypatch, **env):
    for k, v in env.items():
        if v is None:
            monkeypatch.delenv(k, raising=False)
        else:
            monkeypatch.setenv(k, v)
    importlib.reload(config)
    return config


def test_resolve_backend_default_local(monkeypatch):
    cfg = _reload_config(monkeypatch, FORMSCOUT_JUDGE_BACKEND=None, SPACE_ID=None)
    assert cfg.resolve_judge_backend() == "llama_cpp"


def test_resolve_backend_auto_on_zero_gpu_space(monkeypatch):
    cfg = _reload_config(monkeypatch, FORMSCOUT_JUDGE_BACKEND="auto",
                         SPACE_ID="me/space", SPACES_ZERO_GPU="true")
    assert cfg.resolve_judge_backend() == "transformers"
    importlib.reload(config)


def test_resolve_backend_auto_on_cpu_space_stays_llama(monkeypatch):
    # A CPU-only Space must NOT load the 17 GB transformers model.
    cfg = _reload_config(monkeypatch, FORMSCOUT_JUDGE_BACKEND="auto",
                         SPACE_ID="me/space", SPACES_ZERO_GPU=None, ZERO_GPU=None)
    assert cfg.resolve_judge_backend() == "llama_cpp"
    importlib.reload(config)


def test_resolve_backend_explicit(monkeypatch):
    cfg = _reload_config(monkeypatch, FORMSCOUT_JUDGE_BACKEND="llama_cpp", SPACE_ID="me/space")
    assert cfg.resolve_judge_backend() == "llama_cpp"
    importlib.reload(config)  # restore


def test_factory_returns_llama_cpp_locally(monkeypatch):
    _reload_config(monkeypatch, FORMSCOUT_JUDGE_BACKEND="llama_cpp", SPACE_ID=None)
    client = get_vlm_client()
    assert isinstance(client, LlamaCppClient)
    importlib.reload(config)


def test_transformers_client_available_is_cheap_bool():
    # available must not load/download the model — just report a bool
    from formscout.serving.transformers_vlm import TransformersVLMClient
    c = TransformersVLMClient()
    assert isinstance(c.available, bool)
    c._failed = True
    assert c.available is False


def test_judge_uses_rubric_on_fallback_sentinel():
    from formscout.agents.judge import JudgeAgent
    from formscout.types import BiomechFeatures, ScoreResult, MovementResult, IngestResult
    import numpy as np

    agent = JudgeAgent()

    class _FakeClient:
        available = True

        def complete(self, *a, **k):
            return {"error": "no gpu", "fallback": True, "text": ""}

    agent._client = _FakeClient()
    features = BiomechFeatures(test_name="deep_squat", view="2d", side="na",
                               angles={}, alignments={}, symmetry_delta=None,
                               timing={}, confidence=0.9)
    rubric = ScoreResult(score=2, rationale="rubric says 2", confidence=0.8)
    movement = MovementResult(test_name="deep_squat", side="na", confidence=1.0)
    ingest = IngestResult(frames=[np.zeros((10, 10, 3), np.uint8)], fps=30.0,
                          duration=0.03, n_people=1, width=10, height=10)

    res = agent.run(features, rubric, movement, ingest)
    assert res.score == 2
    assert "rubric-only" in res.rationale