"""centerline 테스트 (Rhino 없이 실행됩니다).

단면 외곽선을 안쪽으로 피복만큼 옮긴 직선들의 교점으로 철근 중심선 꺾임점을 구합니다.
2D 좌표는 (s, z): s = 길이방향, z = 높이.
기준: 기존 프로젝트 rebar_pipeline/rhino/02_build_shape_VII.py (형식 VII, 도면 b=4167.1, c=3158.8)
"""
import math

import pytest

import centerline as cl


# ---- 직선 오프셋 ----

def test_offset_line_right_side_of_rightward_segment_is_below():
    # +s 방향으로 가는 선분의 오른쪽은 아래(-z)
    point, direction = cl.offset_line((0.0, 0.0), (100.0, 0.0), 10.0, "right")
    assert point == pytest.approx((0.0, -10.0))
    assert direction == pytest.approx((1.0, 0.0))


def test_offset_line_left_side_of_rightward_segment_is_above():
    point, direction = cl.offset_line((0.0, 0.0), (100.0, 0.0), 10.0, "left")
    assert point == pytest.approx((0.0, 10.0))


def test_offset_line_downward_segment_right_side_is_minus_s():
    # 아래로 가는 선분의 오른쪽은 -s 쪽 (끝면 s=12100 에서 안쪽)
    point, _ = cl.offset_line((12100.0, 10738.0), (12100.0, 9238.0), 120.0, "right")
    assert point[0] == pytest.approx(11980.0)


def test_offset_line_direction_is_unit_length():
    _, d = cl.offset_line((0.0, 0.0), (30.0, 40.0), 5.0, "left")
    assert math.hypot(*d) == pytest.approx(1.0)


def test_offset_line_rejects_zero_length_segment():
    with pytest.raises(ValueError):
        cl.offset_line((1.0, 1.0), (1.0, 1.0), 10.0, "left")


def test_offset_line_rejects_bad_side():
    with pytest.raises(ValueError):
        cl.offset_line((0.0, 0.0), (1.0, 0.0), 10.0, "up")


# ---- 직선 교점 ----

def test_line_intersection_perpendicular_lines():
    a = ((0.0, 5.0), (1.0, 0.0))
    b = ((7.0, 0.0), (0.0, 1.0))
    assert cl.line_intersection(a, b) == pytest.approx((7.0, 5.0))


def test_line_intersection_diagonal():
    a = ((0.0, 0.0), (1.0, 1.0))
    b = ((10.0, 0.0), (-1.0, 1.0))
    assert cl.line_intersection(a, b) == pytest.approx((5.0, 5.0))


def test_line_intersection_parallel_raises():
    a = ((0.0, 0.0), (1.0, 0.0))
    b = ((0.0, 5.0), (1.0, 0.0))
    with pytest.raises(ValueError):
        cl.line_intersection(a, b)


# ---- 중심선 꺾임점: 단순한 경우 ----

def test_centerline_of_u_shape_inside_a_box():
    # 바깥 외곽: 위에서 왼쪽 벽을 따라 내려가 바닥을 지나 오른쪽 벽을 올라가는 ㄷ자 경로
    segs = [
        ((0.0, 100.0), (0.0, 0.0)),      # 왼쪽 벽, 아래로
        ((0.0, 0.0), (200.0, 0.0)),      # 바닥, 오른쪽으로
        ((200.0, 0.0), (200.0, 100.0)),  # 오른쪽 벽, 위로
    ]
    pts = cl.centerline_points(segs, 10.0, "left")
    # 아래로 가는 선분의 왼쪽은 +s, 오른쪽으로 가는 선분의 왼쪽은 +z (안쪽)
    assert pts[0] == pytest.approx((10.0, 100.0))
    assert pts[1] == pytest.approx((10.0, 10.0))
    assert pts[2] == pytest.approx((190.0, 10.0))
    assert pts[3] == pytest.approx((190.0, 100.0))


def test_centerline_fixed_start_and_end_lengths():
    segs = [
        ((0.0, 100.0), (0.0, 0.0)),
        ((0.0, 0.0), (200.0, 0.0)),
        ((200.0, 0.0), (200.0, 100.0)),
    ]
    pts = cl.centerline_points(segs, 10.0, "left", start_len=30.0, end_len=40.0)
    assert pts[0] == pytest.approx((10.0, 40.0))     # 첫 꺾임점(10,10)에서 위로 30
    assert pts[-1] == pytest.approx((190.0, 50.0))   # 마지막 꺾임점(190,10)에서 위로 40
    assert len(pts) == 4


def test_centerline_single_segment_is_just_offset():
    pts = cl.centerline_points([((0.0, 0.0), (100.0, 0.0))], 10.0, "left")
    assert pts == [pytest.approx((0.0, 10.0)), pytest.approx((100.0, 10.0))]


def test_centerline_single_segment_rejects_fixed_lengths():
    with pytest.raises(ValueError):
        cl.centerline_points([((0.0, 0.0), (100.0, 0.0))], 10.0, "left", start_len=5.0)


def test_centerline_parallel_neighbors_raise():
    segs = [((0.0, 0.0), (100.0, 0.0)), ((100.0, 0.0), (200.0, 0.0))]
    with pytest.raises(ValueError):
        cl.centerline_points(segs, 10.0, "left")


def test_centerline_rejects_empty():
    with pytest.raises(ValueError):
        cl.centerline_points([], 10.0, "left")


# ---- 길이와 꺾임각 ----

def test_segment_lengths_and_total():
    pts = [(0.0, 0.0), (3.0, 4.0), (3.0, 10.0)]
    assert cl.segment_lengths(pts) == pytest.approx([5.0, 6.0])
    assert cl.polyline_length(pts) == pytest.approx(11.0)


def test_turn_angles_right_angle():
    pts = [(0.0, 0.0), (10.0, 0.0), (10.0, 10.0)]
    assert cl.turn_angles(pts) == pytest.approx([90.0])


def test_turn_angles_straight_is_zero():
    pts = [(0.0, 0.0), (10.0, 0.0), (20.0, 0.0)]
    assert cl.turn_angles(pts) == pytest.approx([0.0])


# ---- 형식 VII (대호지교 P1 C8/C10) 도면 값 재현 ----

P1_VII_SEGMENTS = [
    ((12100.0, 10738.0), (12100.0, 9238.0)),   # 끝면, 아래로
    ((12100.0, 9238.0), (8100.0, 7738.0)),     # 끝헌치
    ((8100.0, 7738.0), (4900.0, 7738.0)),      # 바닥
    ((4900.0, 7738.0), (3400.0, 8238.0)),      # 내측헌치
]


def test_shape_vii_matches_drawing_b_and_c():
    pts = cl.centerline_points(P1_VII_SEGMENTS, 120.0, "right", start_len=630.0, end_len=2331.0)
    lengths = cl.segment_lengths(pts)
    assert len(pts) == 5
    assert lengths[0] == pytest.approx(630.0)        # a
    assert lengths[1] == pytest.approx(4167.1, abs=0.1)   # b (도면)
    assert lengths[2] == pytest.approx(3158.8, abs=0.1)   # c (도면)
    assert lengths[3] == pytest.approx(2331.0)       # d


def test_shape_vii_key_points():
    pts = cl.centerline_points(P1_VII_SEGMENTS, 120.0, "right", start_len=630.0, end_len=2331.0)
    assert pts[0] == pytest.approx((11980.0, 9951.16), abs=0.01)   # A
    assert pts[1] == pytest.approx((11980.0, 9321.16), abs=0.01)   # 끝면-끝헌치 교점
    assert pts[2][1] == pytest.approx(7858.0)                      # 바닥 위 120 (7738+120)
    assert pts[3][1] == pytest.approx(7858.0)
    assert pts[3][0] == pytest.approx(4919.47, abs=0.01)


def test_shape_vii_cover_is_120_from_every_face():
    # 중심선 위의 각 꺾임점은 이웃한 두 면에서 모두 120 떨어져 있어야 합니다.
    pts = cl.centerline_points(P1_VII_SEGMENTS, 120.0, "right", start_len=630.0, end_len=2331.0)
    for i, (p0, p1) in enumerate(P1_VII_SEGMENTS[:-1]):
        vertex = pts[i + 1]
        for seg in (P1_VII_SEGMENTS[i], P1_VII_SEGMENTS[i + 1]):
            assert cl.distance_to_line(vertex, seg[0], seg[1]) == pytest.approx(120.0, abs=1e-6)


def test_distance_to_line_basic():
    assert cl.distance_to_line((5.0, 7.0), (0.0, 0.0), (10.0, 0.0)) == pytest.approx(7.0)