"""Tests for Pose2DAgent — model-dependent, skips if YOLO unavailable."""
import inspect
import unittest.mock as mock

import numpy as np
import pytest

from formscout.types import IngestResult, Pose2DResult


def _blank_ingest(n_frames=5, w=640, h=480):
    frames = [np.zeros((h, w, 3), dtype=np.uint8) for _ in range(n_frames)]
    return IngestResult(
        frames=frames, fps=30.0, duration=n_frames / 30.0,
        n_people=1, width=w, height=h,
    )


@pytest.fixture
def pose2d_agent():
    """Create Pose2DAgent, skip if model unavailable."""
    try:
        from formscout.agents.pose2d import Pose2DAgent
        agent = Pose2DAgent()
        return agent
    except Exception as e:
        pytest.skip(f"Pose2D model unavailable: {e}")


class TestPose2DAgent:
    def test_returns_typed_result(self, pose2d_agent):
        result = pose2d_agent.run(_blank_ingest())
        assert isinstance(result, Pose2DResult)
        assert isinstance(result.keypoints, list)
        assert result.fps == pytest.approx(30.0)

    def test_keypoints_per_frame(self, pose2d_agent):
        ingest = _blank_ingest(n_frames=3)
        result = pose2d_agent.run(ingest)
        assert len(result.keypoints) == 3
        for frame_kps in result.keypoints:
            assert isinstance(frame_kps, dict)

    def test_graceful_on_empty_frames(self, pose2d_agent):
        empty = IngestResult(
            frames=[], fps=30.0, duration=0.0,
            n_people=0, width=640, height=480,
        )
        result = pose2d_agent.run(empty)
        assert result.confidence == 0.0
        assert "no frames" in result.notes.lower()

    def test_run_accepts_model_key(self, pose2d_agent):
        sig = inspect.signature(pose2d_agent.run)
        assert "model_key" in sig.parameters
        assert "model_path" not in sig.parameters


def _blank_ingest_3():
    frames = [np.zeros((480, 640, 3), dtype=np.uint8) for _ in range(3)]
    return IngestResult(frames=frames, fps=30.0, duration=0.1, n_people=1, width=640, height=480)


class TestPose2DBackendsMocked:
    """Backend dispatch tests — no real model downloads."""

    def test_yolo_backend_dispatches(self):
        from formscout.agents.pose2d import Pose2DAgent
        fake_kps = [{0: {"x": 10.0, "y": 20.0, "conf": 0.9}} for _ in range(3)]
        with mock.patch("formscout.agents.pose2d._run_yolo", return_value=fake_kps) as m:
            result = Pose2DAgent().run(_blank_ingest_3(), model_key="YOLO26n — nano (0.7M, fastest)")
        m.assert_called_once()
        assert isinstance(result, Pose2DResult)
        assert len(result.keypoints) == 3
        assert result.confidence > 0.0

    def test_mediapipe_backend_dispatches(self):
        from formscout.agents.pose2d import Pose2DAgent
        fake_kps = [{i: {"x": float(i), "y": float(i), "conf": 0.8} for i in range(17)} for _ in range(3)]
        with mock.patch("formscout.agents.pose2d._run_mediapipe", return_value=fake_kps) as m:
            result = Pose2DAgent().run(_blank_ingest_3(), model_key="MediaPipe-Pose — full (~9 MB, CPU-friendly)")
        m.assert_called_once()
        assert isinstance(result, Pose2DResult)
        assert len(result.keypoints) == 3
        assert all(len(f) == 17 for f in result.keypoints)

    def test_sapiens2_backend_dispatches(self):
        from formscout.agents.pose2d import Pose2DAgent
        fake_kps = [{i: {"x": float(i), "y": float(i), "conf": 0.85} for i in range(17)} for _ in range(3)]
        with mock.patch("formscout.agents.pose2d._run_sapiens2", return_value=fake_kps) as m:
            result = Pose2DAgent().run(_blank_ingest_3(), model_key="Sapiens2-0.4B [Phase 3, ~1.6 GB]")
        m.assert_called_once()
        assert isinstance(result, Pose2DResult)
        assert len(result.keypoints) == 3

    def test_unknown_model_key_falls_back(self):
        from formscout.agents.pose2d import Pose2DAgent
        fake_kps = [{0: {"x": 1.0, "y": 2.0, "conf": 0.7}} for _ in range(3)]
        with mock.patch("formscout.agents.pose2d._run_yolo", return_value=fake_kps):
            result = Pose2DAgent().run(_blank_ingest_3(), model_key="nonexistent-model-xyz")
        assert isinstance(result, Pose2DResult)

    def test_confidence_zero_on_empty_keypoints(self):
        from formscout.agents.pose2d import Pose2DAgent
        with mock.patch("formscout.agents.pose2d._run_yolo", return_value=[{}, {}, {}]):
            result = Pose2DAgent().run(_blank_ingest_3(), model_key="YOLO26n — nano (0.7M, fastest)")
        assert result.confidence == 0.0
        assert "no person" in result.notes.lower()