from bookmark.capture_strategies.stable_centered import StableCenteredStrategy
import numpy as np


def make_reference(size=100, color=200):
    return np.full((size, size, 3), color, dtype=np.uint8)


def make_book_frame(size=100, ref_color=200, book_color=50, box=(20, 20, 60, 60)):
    frame = np.full((size, size, 3), ref_color, dtype=np.uint8)
    x, y, w, h = box
    frame[y:y + h, x:x + w] = book_color
    return frame


def test_no_fire_on_empty_reference_frame():
    reference = make_reference()
    strategy = StableCenteredStrategy(reference_frame=reference, guide_box=(20, 20, 60, 60), stable_frames=3)
    assert strategy.observe(reference) is False


def test_no_fire_when_book_too_small():
    reference = make_reference()
    small_book = make_book_frame(box=(40, 40, 10, 10))
    strategy = StableCenteredStrategy(
        reference_frame=reference, guide_box=(20, 20, 60, 60), min_fill_ratio=0.5, stable_frames=3
    )
    for _ in range(5):
        assert strategy.observe(small_book) is False


def test_fires_after_stable_frames_with_book_filling_guide_box():
    reference = make_reference()
    book_frame = make_book_frame(box=(20, 20, 60, 60))
    strategy = StableCenteredStrategy(
        reference_frame=reference, guide_box=(20, 20, 60, 60), min_fill_ratio=0.5, stable_frames=3
    )
    assert strategy.observe(book_frame) is False
    assert strategy.observe(book_frame) is False
    assert strategy.observe(book_frame) is False
    assert strategy.observe(book_frame) is True


def test_fires_only_once():
    reference = make_reference()
    book_frame = make_book_frame(box=(20, 20, 60, 60))
    strategy = StableCenteredStrategy(
        reference_frame=reference, guide_box=(20, 20, 60, 60), min_fill_ratio=0.5, stable_frames=2
    )
    strategy.observe(book_frame)
    strategy.observe(book_frame)
    assert strategy.observe(book_frame) is True
    assert strategy.observe(book_frame) is False