"""Tests for directions.

Oracles hand-derived from ``geometry/planar/{Direction,IntDirection}.java``.
"""

from __future__ import annotations

from freeroute.geometry import Direction, IntDirection, IntPoint, IntVector, Side


def test_normalized_direction_reduces_by_gcd():
    d = IntVector(2, 4).to_normalized_direction()
    assert isinstance(d, IntDirection)
    assert (d.x, d.y) == (1, 2)


def test_normalized_direction_beyond_java_int():
    # gcd reduction stays exact for coordinates far past Java's int range.
    d = IntVector(6 * 10**12, 9 * 10**12).to_normalized_direction()
    assert (d.x, d.y) == (2, 3)


def test_turn_45_degree_cycles():
    right = IntDirection(1, 0)
    assert (right.turn_45_degree(1).x, right.turn_45_degree(1).y) == (1, 1)
    assert (right.turn_45_degree(2).x, right.turn_45_degree(2).y) == (0, 1)
    assert (right.turn_45_degree(4).x, right.turn_45_degree(4).y) == (-1, 0)
    assert (right.turn_45_degree(8).x, right.turn_45_degree(8).y) == (1, 0)


def test_opposite():
    o = IntDirection(1, 2).opposite()
    assert (o.x, o.y) == (-1, -2)


def test_direction_equals_ignores_magnitude_not_sign():
    a = IntDirection(1, 1)
    assert a.equals(IntDirection(3, 3))  # same ray
    assert not a.equals(IntDirection(-1, -1))  # opposite ray
    assert not a.equals(IntDirection(1, 0))


def test_from_points_returns_none_for_equal():
    assert Direction.from_points(IntPoint(1, 1), IntPoint(1, 1)) is None
    d = Direction.from_points(IntPoint(0, 0), IntPoint(4, 4))
    assert (d.x, d.y) == (1, 1)


def test_compare_to_angular_order():
    right = IntDirection(1, 0)
    up = IntDirection(0, 1)
    down = IntDirection(0, -1)
    # angle(right)=0, angle(up)=90, angle(down)=270
    assert right.compare_to(up) == -1
    assert up.compare_to(right) == 1
    assert up.compare_to(down) == -1
    assert right.compare_to(IntDirection(2, 0)) == 0


def test_side_of_direction():
    assert IntDirection(0, 1).side_of(IntDirection(1, 0)) == Side.ON_THE_LEFT