"""
lineart-extractor 单元测试
==========================
运行: pytest tests/ -v
"""
import os
import sys

import numpy as np
import pytest

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from lineartization import (
    LineArtConfig,
    extract_lineart,
    extract_lineart_file,
    load_image,
    save_image,
)


# --------------------------------------------------------------------------- #
#  测试用图: 合成"白底 + 黑字 + 彩色块"
# --------------------------------------------------------------------------- #
@pytest.fixture
def sample_image():
    """构造一张 400x600 的合成图: 白底 + 黑色矩形(模拟文字) + 彩色块。"""
    img = np.full((400, 600, 3), 255, np.uint8)

    # 中央"文字区": 密集小黑块
    rng = np.random.default_rng(42)
    for _ in range(120):
        x = rng.integers(180, 420)
        y = rng.integers(150, 250)
        img[y:y + 4, x:x + 4] = 0

    # 左侧彩色块(模拟山体)
    img[60:160, 20:180] = (60, 160, 80)     # 绿
    img[160:220, 20:180] = (80, 120, 200)   # 偏蓝

    # 右侧一个红色圆(模拟灯笼)
    import cv2
    cv2.circle(img, (500, 120), 40, (40, 40, 200), 3)

    return img


# --------------------------------------------------------------------------- #
#  测试
# --------------------------------------------------------------------------- #
def test_load_save_roundtrip(tmp_path, sample_image):
    """读写往返一致。"""
    p = tmp_path / "in.png"
    save_image(str(p), sample_image)
    loaded = load_image(str(p))
    assert loaded.shape == sample_image.shape
    assert np.allclose(loaded, sample_image, atol=2)


def test_extract_returns_binary(sample_image):
    """输出必须是二值(0/255)白底黑线。"""
    out = extract_lineart(sample_image, LineArtConfig(enable_green_smoothing=False))
    assert out.dtype == np.uint8
    assert out.ndim == 2
    uniq = np.unique(out)
    assert set(uniq.tolist()).issubset({0, 255})
    assert out.shape == sample_image.shape[:2]


def test_extract_has_content(sample_image):
    """输出不能空白、也不能全黑。"""
    out = extract_lineart(sample_image, LineArtConfig(enable_green_smoothing=False))
    black_ratio = (out < 128).mean() * 100
    assert 0.1 < black_ratio < 90.0


def test_line_width_effect(sample_image):
    """线宽参数应影响黑占比(越粗越多)。"""
    cfg1 = LineArtConfig(line_width=1, enable_green_smoothing=False)
    cfg3 = LineArtConfig(line_width=3, enable_green_smoothing=False)
    r1 = (extract_lineart(sample_image, cfg1) < 128).mean()
    r3 = (extract_lineart(sample_image, cfg3) < 128).mean()
    assert r3 > r1


def test_green_smoothing_toggle(sample_image):
    """绿块抹平开关都应能正常出图。"""
    for flag in (True, False):
        cfg = LineArtConfig(enable_green_smoothing=flag)
        out = extract_lineart(sample_image, cfg)
        assert (out < 128).mean() > 0


def test_protect_areas(sample_image):
    """保护区域内的线条不应被删。"""
    cfg = LineArtConfig(
        enable_green_smoothing=False,
        protect_areas=[(0, 200, 0, 400)],
    )
    out = extract_lineart(sample_image, cfg)
    assert (out < 128).sum() > 0


def test_file_interface(tmp_path, sample_image):
    """extract_lineart_file 接口正常。"""
    src = tmp_path / "src.png"
    dst = tmp_path / "dst.png"
    save_image(str(src), sample_image)
    result = extract_lineart_file(str(src), str(dst),
                                  LineArtConfig(enable_green_smoothing=False))
    assert os.path.exists(result)
    assert result == str(dst)


def test_load_missing_file():
    """读取不存在的文件应抛异常。"""
    with pytest.raises((FileNotFoundError, Exception)):
        load_image("___no_such_file___.png")


def test_chinese_path(tmp_path, sample_image):
    """中文路径应正常工作。"""
    src = tmp_path / "中文图片.png"
    dst = tmp_path / "输出_láthair.png"
    save_image(str(src), sample_image)
    out = extract_lineart_file(str(src), str(dst),
                               LineArtConfig(enable_green_smoothing=False))
    assert os.path.exists(out)