# Copyright (C) 2023  Tomasz Kramkowski <tomasz@kramkow.ski>
# SPDX-License-Identifier: MIT
import unittest
from collections.abc import Iterator
from contextlib import contextmanager
from tempfile import TemporaryDirectory

from brightness import main


class TempSysfs:
    def __init__(self, path: str) -> None:
        self.path = path

    def read(self, name) -> str:
        with open(self.path + "/" + name) as f:
            return f.read()

    @property
    def brightness(self) -> int:
        return int(self.read("brightness").rstrip())

    def max_brightness(self) -> int:
        return int(self.read("max_brightness").rstrip())


@contextmanager
def fake_sysfs(brightness: int, max_brightness: int) -> Iterator[TempSysfs]:
    with TemporaryDirectory() as d:
        with open(d + "/brightness", "w") as f:
            f.write(str(brightness) + "\n")
        with open(d + "/max_brightness", "w") as f:
            f.write(str(max_brightness) + "\n")
        yield TempSysfs(d)


class TestCLI(unittest.TestCase):
    def test_increment_10(self):
        with fake_sysfs(brightness=70, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "+10"])
            self.assertGreater(sysfs.brightness, 70)
            self.assertLessEqual(sysfs.brightness, 255)

    def test_decrement_10(self):
        with fake_sysfs(brightness=70, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "-10"])
            self.assertGreaterEqual(sysfs.brightness, 0)
            self.assertLess(sysfs.brightness, 70)

    def test_increase_small(self):
        with fake_sysfs(brightness=0, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "+1"])
            self.assertEqual(sysfs.brightness, 1)

    def test_decrease_small(self):
        with fake_sysfs(brightness=1, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "-1"])
            self.assertEqual(sysfs.brightness, 0)

    def test_increase_zero(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "+0"])
            self.assertEqual(sysfs.brightness, 127)

    def test_decrease_zero(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "-0"])
            self.assertEqual(sysfs.brightness, 127)

    def test_double(self):
        with fake_sysfs(brightness=15, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "+" + str(1 / 8 * 100)])
            self.assertEqual(sysfs.brightness, 31)

    def test_halve(self):
        with fake_sysfs(brightness=15, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, str(-(1 / 8 * 100))])
            self.assertEqual(sysfs.brightness, 7)

    def test_clamp_low(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "-100"])
            self.assertEqual(sysfs.brightness, 0)

    def test_clamp_high(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "+100"])
            self.assertEqual(sysfs.brightness, 255)

    def test_absolute(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 0)
            main(["brightness", sysfs.path, "12.5"])
            self.assertEqual(sysfs.brightness, 1)
            main(["brightness", sysfs.path, "25.0"])
            self.assertEqual(sysfs.brightness, 3)
            main(["brightness", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 255)

    def test_min_value(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", "--min", "0", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 0)
            main(["brightness", "--min", "10", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 10)
            main(["brightness", "--min", "0%", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 0)
            main(["brightness", "--min", "12.5%", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 1)

    def test_max_value(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", "--max", "255", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 255)
            main(["brightness", "--max", "245", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 245)
            main(["brightness", "--max", "100%", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 255)
            main(["brightness", "--max", "87.5%", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 127)

    def test_min_max(self):
        with fake_sysfs(brightness=127, max_brightness=255) as sysfs:
            main(["brightness", "--min", "0", "--max", "255", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 0)
            main(["brightness", "--min", "0", "--max", "255", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 255)
            main(["brightness", "--min", "10", "--max", "245", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 10)
            main(["brightness", "--min", "10", "--max", "245", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 245)
            main(["brightness", "--min", "0%", "--max", "100%", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 0)
            main(["brightness", "--min", "0%", "--max", "100%", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 255)
            main(["brightness", "--min", "12.5%", "--max", "87.5%", sysfs.path, "0"])
            self.assertEqual(sysfs.brightness, 1)
            main(["brightness", "--min", "12.5%", "--max", "87.5%", sysfs.path, "100"])
            self.assertEqual(sysfs.brightness, 127)