from decimal import Decimal

import pytest

from app.engine.pie import UEBRIGE, pie_slices

D = Decimal


def test_leer_und_nullwerte():
    assert pie_slices([]) == []
    assert pie_slices([("A", D("0")), ("B", D("-5"))]) == []


def test_segmente_lueckenlos_und_anteile():
    sl = pie_slices([("C", D("20")), ("A", D("50")), ("B", D("30"))])
    assert [s.label for s in sl] == ["A", "B", "C"]
    assert [s.color for s in sl] == ["s1", "s2", "s3"]
    assert [s.share for s in sl] == [D("50.0"), D("30.0"), D("20.0")]
    assert sl[0].start == 0.0 and sl[-1].end == pytest.approx(1.0)
    for a, b in zip(sl, sl[1:]):
        assert a.end == pytest.approx(b.start)
    assert sl[0].path.startswith("M 0 0 L 0.0000 -1.0000 A 1 1 0 0 1 ")


def test_large_arc_flag():
    a, b = pie_slices([("A", D("70")), ("B", D("30"))])
    assert " A 1 1 0 1 1 " in a.path
    assert " A 1 1 0 0 1 " in b.path


def test_einzelsegment_ist_vollkreis():
    (s,) = pie_slices([("A", D("12.34"))])
    assert s.path is None and s.share == D("100.0") and s.color == "s1"


def test_kleine_werte_zu_uebrige():
    sl = pie_slices([("A", D("95")), ("B", D("2")), ("C", D("2")), ("D", D("1"))])
    assert [s.label for s in sl] == ["A", UEBRIGE]
    u = sl[1]
    assert (u.value, u.color, u.merged, u.members) == (D("5"), "uebrige", True, ("B", "C", "D"))


def test_einzelner_kleiner_wert_behaelt_namen():
    sl = pie_slices([("A", D("98")), ("B", D("2"))])
    assert [(s.label, s.color, s.merged) for s in sl] == [("A", "s1", False), ("B", "uebrige", False)]


def test_hoechstens_acht_benannte_segmente():
    sl = pie_slices([(f"K{i}", D("10")) for i in range(10)], rest=D("5"),
                    rest_label="Frei verfügbar")
    assert [s.color for s in sl] == ["s1", "s2", "s3", "s4", "s5", "s6", "s7", "s8",
                                     "uebrige", "frei"]
    assert sl[-2].merged and sl[-2].members == ("K8", "K9")


def test_acht_kategorien_ohne_uebrige():
    sl = pie_slices([(f"K{i}", D("10")) for i in range(8)])
    assert [s.color for s in sl] == [f"s{i}" for i in range(1, 9)]
    assert not any(s.merged for s in sl)


def test_rest_wird_nie_zusammengefasst():
    sl = pie_slices([("A", D("99.5"))], rest=D("0.5"), rest_label="Frei verfügbar")
    assert [(s.label, s.color, s.merged) for s in sl] == [("A", "s1", False), ("Frei verfügbar", "frei", False)]
    assert sl[1].share == D("0.5")


def test_nur_rest_ist_vollkreis():
    (s,) = pie_slices([], rest=D("100"), rest_label="Frei verfügbar")
    assert (s.label, s.color, s.path) == ("Frei verfügbar", "frei", None)


def test_rest_none_oder_null_ignoriert():
    assert len(pie_slices([("A", D("1"))], rest=None)) == 1
    assert len(pie_slices([("A", D("1"))], rest=D("0"), rest_label="X")) == 1