import numpy as np
from sfm.shape_metrics import channel_shape, shape_from_samples

def test_needle_spike_high_crest_few_near_peak():
    x = np.zeros(1024); x[500] = 1.0          # one isolated spike
    s = channel_shape(x)
    assert s["sample_count"] == 1024
    assert s["crest_factor"] > 15             # peak towers over rms
    assert s["near_peak_count"] <= 3          # almost nothing near the peak

def test_ringing_low_crest_many_near_peak():
    t = np.arange(1024)
    x = np.sin(2*np.pi*t/32) * np.exp(-t/4000)  # decaying oscillation
    s = channel_shape(x)
    assert s["crest_factor"] < 6
    assert s["near_peak_count"] > 30          # many samples near the peak

def test_channel_shape_none_for_unusable():
    assert channel_shape(np.zeros(1024)) is None   # flat / all-zero
    assert channel_shape(np.array([1.0])) is None  # too short

def test_shape_from_samples_picks_max_peak_axis():
    chans = {"Tran": np.zeros(1024), "Vert": np.zeros(1024), "Long": np.zeros(1024)}
    chans["Long"][10] = 0.5
    chans["Vert"] = np.sin(np.arange(1024)/5) * 0.01
    s = shape_from_samples(chans)
    assert s["axis"] == "Long"                # Long has the biggest peak
    assert s["near_peak_count"] <= 3

def test_shape_from_samples_none_when_no_geo():
    assert shape_from_samples({"MicL": np.ones(1024)}) is None