import hashlib
import sys
import tempfile
import unittest
from pathlib import Path

from PIL import Image

SCRIPTS = Path(__file__).resolve().parents[1] / "scripts"
sys.path.insert(0, str(SCRIPTS))

from build_raster_assets import (
    build_opaque_cover_crop,
    build_opaque_resize,
    extract_warm_gold_frame,
    save_png,
)


class RasterAssetBuilderTests(unittest.TestCase):
    """锁定迁移后的两类背景处理与 G01 暖金边框提取语义。"""

    def test_opaque_resize_uses_locked_output_size_and_rgb(self):
        source = Image.new("RGBA", (2, 3), (120, 80, 40, 128))
        output = build_opaque_resize(source, (4, 6))
        self.assertEqual((4, 6), output.size)
        self.assertEqual("RGB", output.mode)

    def test_cover_crop_centers_the_scaled_source(self):
        source = Image.new("RGB", (2, 1), (255, 0, 0))
        source.putpixel((1, 0), (0, 0, 255))
        output = build_opaque_cover_crop(source, (2, 2))
        self.assertEqual((2, 2), output.size)
        self.assertEqual("RGB", output.mode)
        self.assertNotEqual(output.getpixel((0, 0)), output.getpixel((1, 0)))

    def test_warm_gold_frame_keeps_only_the_edge_band(self):
        source = Image.new("RGBA", (5, 5), (180, 140, 80, 255))
        config = {
            "borderBand": 1,
            "redGreenMin": 15,
            "greenBlueMin": 12,
            "redBlueMin": 35,
            "redMaxExclusive": 245,
            "blueMaxExclusive": 180,
            "alphaOffset": 25,
            "alphaScale": 6,
        }
        output = extract_warm_gold_frame(source, config)
        self.assertGreater(output.getpixel((0, 2))[3], 0)
        self.assertEqual((0, 0, 0, 0), output.getpixel((2, 2)))

    def test_warm_gold_frame_rejects_non_gold_and_clears_hidden_rgb(self):
        source = Image.new("RGBA", (1, 1), (100, 150, 100, 255))
        config = {
            "borderBand": 1,
            "redGreenMin": 15,
            "greenBlueMin": 12,
            "redBlueMin": 35,
            "redMaxExclusive": 245,
            "blueMaxExclusive": 180,
            "alphaOffset": 25,
            "alphaScale": 6,
        }
        output = extract_warm_gold_frame(source, config)
        self.assertEqual((0, 0, 0, 0), output.getpixel((0, 0)))

    def test_png_save_is_srgb_and_byte_deterministic(self):
        with tempfile.TemporaryDirectory() as directory:
            first = Path(directory) / "first.png"
            second = Path(directory) / "second.png"
            image = Image.new("RGB", (4, 4), (230, 220, 200))
            save_png(image, first)
            save_png(image, second)
            self.assertEqual(first.read_bytes(), second.read_bytes())
            self.assertEqual(
                hashlib.sha256(first.read_bytes()).hexdigest(),
                hashlib.sha256(second.read_bytes()).hexdigest(),
            )
            with Image.open(first) as opened:
                self.assertIn("srgb", opened.info)


if __name__ == "__main__":
    unittest.main()