using KeyOverlay.Core;
using Xunit;

namespace KeyOverlay.Core.Tests;

public class KeyLocalizerTests
{
    // Pretends to be a Russian layout: only a few keys are mapped.
    private static string? FakeRussian(string keycode, bool shift) => (keycode, shift) switch
    {
        ("KC_Q", false) => "й",
        ("KC_Q", true) => "Й",
        ("KC_1", true) => "!",
        ("KC_SLASH", true) => ",",
        ("KC_COMMA", false) => "б",
        _ => null,
    };

    [Fact]
    public void Letter_IsShownUppercaseInTheActiveLanguage()
    {
        var localized = KeyLocalizer.Localize(Keycodes.Describe("KC_Q"), FakeRussian);
        Assert.Equal("Й", localized.Main);
    }

    [Fact]
    public void ShiftWrappedKey_UsesShiftedCharacter()
    {
        var localized = KeyLocalizer.Localize(Keycodes.Describe("LSFT(KC_SLASH)"), FakeRussian);
        Assert.Equal(",", localized.Main);
    }

    [Fact]
    public void Punctuation_IsReplacedWithLayoutCharacter()
    {
        var localized = KeyLocalizer.Localize(Keycodes.Describe("KC_COMMA"), FakeRussian);
        Assert.Equal("Б", localized.Main); // a letter on a punctuation key is still shown uppercase
    }

    [Fact]
    public void Localizing_KeepsBaseKeycodeForHighlighting()
    {
        var localized = KeyLocalizer.Localize(Keycodes.Describe("KC_Q"), FakeRussian);
        Assert.Equal("KC_Q", localized.BaseKeycode);
    }

    [Fact]
    public void ModTap_KeepsModifierHintAndLocalizesTapKey()
    {
        var localized = KeyLocalizer.Localize(Keycodes.Describe("LCTL_T(KC_Q)"), FakeRussian);
        Assert.Equal("Й", localized.Main);
        Assert.Equal("Ctrl", localized.Sub);
    }

    [Theory]
    [InlineData("KC_ESCAPE")]
    [InlineData("KC_SPACE")]
    [InlineData("KC_LSHIFT")]
    [InlineData("KC_RIGHT")]
    [InlineData("MO(2)")]
    [InlineData("LCTL(KC_Q)")]
    public void NonCharacterKeys_AreLeftUntouched(string code)
    {
        var original = Keycodes.Describe(code);
        Assert.Equal(original, KeyLocalizer.Localize(original, FakeRussian));
    }

    [Fact]
    public void UnknownCharacter_FallsBackToDefaultLabel()
    {
        var original = Keycodes.Describe("KC_W"); // FakeRussian has no mapping for W
        Assert.Equal(original, KeyLocalizer.Localize(original, FakeRussian));
    }

    [Fact]
    public void ControlCharacterResult_FallsBackToDefaultLabel()
    {
        var original = Keycodes.Describe("KC_Q");
        var localized = KeyLocalizer.Localize(original, (_, _) => "\u0011");
        Assert.Equal(original, localized);
    }

    [Theory]
    [InlineData("KC_A", true)]
    [InlineData("KC_5", true)]
    [InlineData("KC_GRAVE", true)]
    [InlineData("KC_SCOLON", true)]
    [InlineData("KC_F1", false)]
    [InlineData("KC_ENTER", false)]
    public void IsCharacterKey_CoversLettersDigitsAndPunctuation(string code, bool expected) =>
        Assert.Equal(expected, Keycodes.IsCharacterKey(code));

    [Theory]
    [InlineData("KC_A", 0x1E)]
    [InlineData("KC_1", 0x02)]
    [InlineData("KC_SLASH", 0x35)]
    public void ToScanCode_ReturnsPhysicalKeyCode(string code, int expected) =>
        Assert.Equal(expected, ScanCodes.ToScanCode(code));

    [Fact]
    public void ToScanCode_ReturnsNullForUnknownKeycode() =>
        Assert.Null(ScanCodes.ToScanCode("KC_NOPE"));
}