"""Tests for the High-quality profile fill-the-disc bitrate math."""

from devedeng.project import compute_high_profile_bitrate as calc

CAP_KB = 3_780_000.0  # 4.2 GB * 0.90 margin, in kBytes
FLOOR = 3000
CAP = 9000


def audio_kbits(rate_kbps, runtime_s, streams=1):
    return rate_kbps * streams * runtime_s


def test_short_movie_one_disc_at_cap():
    # 30 min: tiny, so bitrate is pinned at the 9000k cap, one disc
    n, br = calc(1800, audio_kbits(448, 1800), CAP_KB)
    assert n == 1
    assert br == CAP


def test_two_hours_fills_one_disc():
    n, br = calc(7200, audio_kbits(448, 7200), CAP_KB)
    assert n == 1
    assert FLOOR <= br <= CAP
    # should be comfortably above the floor (filling the disc)
    assert br > 3500


def test_four_hours_two_discs():
    n, br = calc(14400, audio_kbits(448, 14400), CAP_KB)
    assert n == 2
    assert FLOOR <= br <= CAP


def test_eight_hours_multiple_discs():
    n, br = calc(28800, audio_kbits(448, 28800), CAP_KB)
    assert n >= 3
    assert br >= FLOOR


def test_zero_runtime_guard():
    assert calc(0, 0, CAP_KB) == (1, CAP)


def test_bitrate_always_within_bounds():
    for rt in (300, 1800, 3600, 7200, 14400, 30000, 60000):
        n, br = calc(rt, audio_kbits(448, rt), CAP_KB)
        assert FLOOR <= br <= CAP, (rt, br)
        assert n >= 1


def test_filled_content_does_not_exceed_disc_capacity():
    # the chosen bitrate must not overflow the n discs it claims to fill
    for rt in (1800, 7200, 14400, 28800):
        ak = audio_kbits(448, rt)
        n, br = calc(rt, ak, CAP_KB)
        used_kbits = br * rt + ak
        assert used_kbits <= n * CAP_KB * 8 + 1  # +1 for rounding slack


def test_menu_reservation_reduces_video_budget():
    rt = 7200
    ak = audio_kbits(448, rt)
    n0, br0 = calc(rt, ak, CAP_KB, menu_kbytes=0)
    n1, br1 = calc(rt, ak, CAP_KB, menu_kbytes=200_000)
    # with a menu eating space, the fill bitrate can only be <= the no-menu one
    assert br1 <= br0