import numpy as np
import pytest


def test_extract_frame_returns_bgr_array(tmp_path):
    """extract_frame should return an HxWx3 BGR numpy array."""
    from inspection.frames import extract_frame

    # Create a tiny test video (10 frames, 64x48)
    import cv2
    video_path = str(tmp_path / "test.mp4")
    writer = cv2.VideoWriter(
        video_path, cv2.VideoWriter_fourcc(*"mp4v"), 30, (64, 48)
    )
    for i in range(10):
        frame = np.full((48, 64, 3), i * 25, dtype=np.uint8)
        writer.write(frame)
    writer.release()

    frame = extract_frame(video_path, 0)
    assert isinstance(frame, np.ndarray)
    assert frame.shape == (48, 64, 3)
    assert frame.dtype == np.uint8


def test_extract_frame_different_indices(tmp_path):
    """Different frame indices should return different pixel data."""
    from inspection.frames import extract_frame
    import cv2

    video_path = str(tmp_path / "test.mp4")
    writer = cv2.VideoWriter(
        video_path, cv2.VideoWriter_fourcc(*"mp4v"), 30, (64, 48)
    )
    for i in range(10):
        frame = np.full((48, 64, 3), i * 25, dtype=np.uint8)
        writer.write(frame)
    writer.release()

    f0 = extract_frame(video_path, 0)
    f5 = extract_frame(video_path, 5)
    assert not np.array_equal(f0, f5)


def test_extract_frame_out_of_range(tmp_path):
    """Out-of-range frame index should raise ValueError."""
    from inspection.frames import extract_frame
    import cv2

    video_path = str(tmp_path / "test.mp4")
    writer = cv2.VideoWriter(
        video_path, cv2.VideoWriter_fourcc(*"mp4v"), 30, (64, 48)
    )
    for i in range(10):
        writer.write(np.zeros((48, 64, 3), dtype=np.uint8))
    writer.release()

    with pytest.raises(ValueError, match="out of range"):
        extract_frame(video_path, 999)


def test_crop_frame_to_bbox():
    """crop_frame should extract the bbox region with padding."""
    from inspection.frames import crop_frame

    frame = np.zeros((200, 300, 3), dtype=np.uint8)
    # Fill a known region with white
    frame[50:100, 80:180] = 255

    bbox = [80, 50, 180, 100]  # x1, y1, x2, y2
    crop = crop_frame(frame, bbox, padding=0.0)
    assert crop.shape == (50, 100, 3)
    assert np.all(crop == 255)


def test_crop_frame_with_padding():
    """Padding should expand the crop region, clamped to frame bounds."""
    from inspection.frames import crop_frame

    frame = np.zeros((200, 300, 3), dtype=np.uint8)
    bbox = [100, 50, 200, 150]  # 100x100 box
    crop = crop_frame(frame, bbox, padding=0.5)
    # 50% padding on a 100x100 box = 50px each side
    # Expected: x=[50,250], y=[0,200] (clamped)
    assert crop.shape[0] > 100
    assert crop.shape[1] > 100


def test_crop_frame_clamped_to_bounds():
    """Padding that exceeds frame bounds should be clamped."""
    from inspection.frames import crop_frame

    frame = np.zeros((100, 100, 3), dtype=np.uint8)
    bbox = [0, 0, 100, 100]
    crop = crop_frame(frame, bbox, padding=1.0)
    # Should not exceed original frame dimensions
    assert crop.shape[0] <= 100
    assert crop.shape[1] <= 100