import numpy as np
from app.services.boundary_detector import find_boundaries

def test_no_boundary_for_identical_embeddings():
    emb = np.ones((10, 768))
    assert find_boundaries(emb, hop_duration=5.0, min_segment_duration=10.0) == []

def test_boundary_at_sharp_transition():
    a = np.random.randn(768)
    b = -a
    emb = np.stack([a] * 5 + [b] * 5)
    boundaries = find_boundaries(emb, hop_duration=5.0, min_segment_duration=10.0)
    assert len(boundaries) >= 1
    assert 3 <= boundaries[0] <= 6

def test_returns_list_of_ints():
    emb = np.random.randn(8, 768)
    for b in find_boundaries(emb, hop_duration=5.0, min_segment_duration=10.0):
        assert isinstance(b, int)

def test_single_chunk_returns_empty():
    assert find_boundaries(np.random.randn(1, 768), hop_duration=5.0, min_segment_duration=10.0) == []