"""Tests for MouseModel and ai_mouse.generate()."""
from __future__ import annotations

import pytest


def test_mouse_model_init_default() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    assert m._seq_len > 0
    assert m._session is not None
    m.close()


def test_mouse_model_generate_returns_correct_shape() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    pts = m.generate((100, 200), (900, 400))
    assert len(pts) == 66  # 64 moves + 2 clicks
    for x, y, t in pts:
        assert isinstance(x, int)
        assert isinstance(y, int)
        assert isinstance(t, int)


def test_mouse_model_click_false_omits_clicks() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    pts = m.generate((100, 200), (900, 400), click=False)
    assert len(pts) == 64


def test_mouse_model_seed_reproducibility() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    a = m.generate((100, 200), (900, 400), seed=42)
    b = m.generate((100, 200), (900, 400), seed=42)
    assert a == b


def test_mouse_model_invalid_path_raises_model_load_error() -> None:
    from ai_mouse.mouse import MouseModel
    from ai_mouse.errors import ModelLoadError
    with pytest.raises(ModelLoadError):
        MouseModel(model_path="/nonexistent/path/here")


def test_mouse_model_timestamps_monotonic() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    pts = m.generate((100, 200), (900, 400))
    times = [p[2] for p in pts]
    for i in range(1, len(times)):
        assert times[i] >= times[i - 1]


def test_mouse_model_starts_and_ends_near_endpoints() -> None:
    from ai_mouse.mouse import MouseModel
    start = (100, 200)
    end = (900, 400)
    m = MouseModel()
    pts = m.generate(start, end)
    assert abs(pts[0][0] - start[0]) < 30
    assert abs(pts[0][1] - start[1]) < 30
    last_move = pts[-3]  # last 2 are click events
    assert abs(last_move[0] - end[0]) < 30
    assert abs(last_move[1] - end[1]) < 30


def test_mouse_model_n_points_parameter() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    pts = m.generate((100, 200), (900, 400), n_points=32)
    # 32 moves + 2 clicks
    assert len(pts) == 34


def test_mouse_model_click_events_have_matching_coords() -> None:
    from ai_mouse.mouse import MouseModel
    m = MouseModel()
    pts = m.generate((100, 200), (900, 400))
    down, up = pts[-2], pts[-1]
    assert down[0] == up[0]
    assert down[1] == up[1]
    assert up[2] > down[2]
    # Within click_dist bounds 20..500
    assert 20 <= up[2] - down[2] <= 500


def test_no_sharp_turns_or_walls_near_endpoint() -> None:
    """Guard against the two endpoint artifact classes:

    - jagged hook/zigzag chains (two or more >90° turns between
      consecutive substantial segments) in the final approach (the old
      tail-drag created hooks); a single reversal is the natural
      overshoot-and-correct gesture and is allowed;
    - vertical walls: many points stacked at the target's forward
      position (the old clip(0,1) stacked overshoot at forward=1).
    """
    import numpy as np

    from ai_mouse import generate

    cases = [((100, 300), (900, 350)), ((100, 100), (700, 600)),
             ((800, 200), (150, 550))]
    for (start, end) in cases:
        for seed in range(6):
            pts = generate(start, end, seed=seed, click=False)
            arr = np.array([(x, y) for x, y, _ in pts], dtype=float)
            tail = arr[-12:]
            seg = np.diff(tail, axis=0)
            lens = np.linalg.norm(seg, axis=1)
            # Only consider substantial segments: integer-pixel staircase
            # on 1-2 px steps produces spurious 90° angles.
            keep = lens >= 3.0
            headings = np.arctan2(seg[keep][:, 1], seg[keep][:, 0])
            if len(headings) >= 2:
                turns = np.abs(np.diff(np.unwrap(headings)))
                sharp = int(np.sum(np.degrees(turns) > 90.0))
                # A single large-angle reversal is the natural
                # overshoot-and-correct gesture (soften_forward allows
                # overshoot; warp_endpoints pins the final point). Two or
                # more mean a jagged hook/zigzag chain — the artifact class.
                assert sharp <= 1, (
                    f"{start}->{end} seed={seed}: {sharp} turns >90° "
                    f"in final approach"
                )
            # Vertical wall: >=4 consecutive tail points within 2 px of
            # the target x while spanning >10 px of y.
            near_x = np.abs(tail[:, 0] - end[0]) <= 2.0
            run = 0
            for i, flag in enumerate(near_x[:-1]):  # exclude final point
                run = run + 1 if flag else 0
                assert run < 4 or np.ptp(tail[near_x][:, 1]) <= 10.0, (
                    f"{start}->{end} seed={seed}: vertical wall at target x"
                )