import math

import pytest

from hef.catalog import Record
from hef.selection import Coordinate, Weights, distance, record_coordinate


def make_record(**overrides):
    base = dict(
        id="r",
        title="t",
        source_url="u",
        source_archive="internet_archive",
        license="public_domain",
        mode="video",
        left=0,
        right=0,
        dark=0,
        light=0,
        duration_s=600,
        file_path="/media/r.mp4",
    )
    base.update(overrides)
    return Record(**base)


def test_distance_zero_for_same_point():
    c = Coordinate(2, 2, 2, 2)
    assert distance(c, c) == 0.0


def test_distance_is_euclidean_by_default():
    a = Coordinate(0, 0, 0, 0)
    b = Coordinate(1, 1, 1, 1)
    assert distance(a, b) == pytest.approx(2.0)  # sqrt(1+1+1+1)


def test_weights_scale_planes_independently():
    a = Coordinate(0, 0, 0, 0)
    brain_only = Coordinate(1, 0, 0, 0)
    mood_only = Coordinate(0, 0, 1, 0)
    w = Weights(brain=4.0, mood=1.0)
    assert distance(a, brain_only, w) == pytest.approx(2.0)   # sqrt(4*1)
    assert distance(a, mood_only, w) == pytest.approx(1.0)    # sqrt(1*1)


def test_record_coordinate_extracts_axes():
    record = make_record(left=1, right=2, dark=3, light=4)
    assert record_coordinate(record) == Coordinate(1, 2, 3, 4)


from hef.selection import candidates_for_mode


def test_candidates_filter_to_exact_mode():
    records = [make_record(id="v", mode="video"), make_record(id="a", mode="audio")]
    result = candidates_for_mode(records, "audio", pool_size=4)
    assert [r.id for r in result] == ["a"]


def test_av_does_not_fall_back_when_enough_av():
    records = [make_record(id=f"av{i}", mode="av") for i in range(4)]
    records.append(make_record(id="a", mode="audio"))
    result = candidates_for_mode(records, "av", pool_size=4)
    assert {r.id for r in result} == {"av0", "av1", "av2", "av3"}


def test_av_falls_back_to_audio_and_video_when_thin():
    records = [
        make_record(id="av0", mode="av"),
        make_record(id="a", mode="audio"),
        make_record(id="v", mode="video"),
    ]
    result = candidates_for_mode(records, "av", pool_size=4)
    assert {r.id for r in result} == {"av0", "a", "v"}


def test_candidates_rejects_none_mode():
    with pytest.raises(ValueError):
        candidates_for_mode([], "none", pool_size=4)