"""Tests for pure peer statistics."""

from __future__ import annotations

import math

from app.services import fundamentals_peers as pr


def test_median_ranks_at_50_tie_aware():
    s = pr.peer_stat(3, [1, 2, 3, 4, 5], higher_is_better=True)
    assert s.median == 3
    assert s.favorable_percentile == 50  # tie-aware rank of the median
    assert s.peer_count == 5


def test_all_equal_peers_rank_at_50():
    s = pr.peer_stat(3, [3, 3, 3, 3, 3], higher_is_better=True)
    assert s.favorable_percentile == 50  # not 100 — ties don't get full credit


def test_peer_stat_lower_is_better_flips_direction():
    assert pr.peer_stat(3, [1, 2, 3, 4, 5], higher_is_better=False).favorable_percentile == 50


def test_peer_stat_unique_top_and_bottom():
    assert pr.peer_stat(5, [1, 2, 3, 4, 5], higher_is_better=True).favorable_percentile == 100
    assert pr.peer_stat(1, [1, 2, 3, 4, 5], higher_is_better=True).favorable_percentile == 0


def test_peer_stat_requires_min_valid_peers():
    assert pr.peer_stat(3, [1, 2, 3, None], higher_is_better=True) is None  # 3 valid < 5
    assert pr.peer_stat(None, [1, 2, 3, 4, 5], higher_is_better=True) is None  # null subject


def test_peer_stat_excludes_null_and_non_finite():
    s = pr.peer_stat(3, [1, 2, 3, 4, 5, None, math.nan, math.inf, -math.inf], higher_is_better=True)
    assert s.peer_count == 5  # nulls + NaN/inf dropped
    # a non-finite subject is invalid
    assert pr.peer_stat(math.nan, [1, 2, 3, 4, 5], higher_is_better=True) is None


def test_net_debt_is_not_peer_eligible():
    assert pr.peer_stat_for("net_debt", 100, [10, 20, 30, 40, 50]) is None  # size-dependent
    assert pr.peer_stat_for("net_debt_to_ebitda", 1.0, [1, 2, 3, 4, 5]) is not None


def test_peer_stat_for_uses_polarity():
    # pe is lower-is-better: a low pe beats most peers
    s = pr.peer_stat_for("pe", 10, [10, 20, 30, 40, 50])
    assert s.favorable_percentile == 100


def test_two_digit_sic():
    assert pr.two_digit_sic("7372") == "73"
    assert pr.two_digit_sic("3571") == "35"
    assert pr.two_digit_sic(None) is None
    assert pr.two_digit_sic("x") is None