namespace Zcbot.WindowsNode.Tests;

public sealed class SoftwarePageViewModelTests
{
    [Fact]
    public async Task Refresh_PopulatesSoftwareCardsAndExecutionState()
    {
        var service = new FakeSoftwareManagementService(
            Snapshot("origin", "Origin", available: true),
            Snapshot("ansys", "ANSYS", available: false, active: true));
        using var viewModel = new SoftwarePageViewModel(service);

        await viewModel.RefreshAsync();

        Assert.Equal(2, viewModel.Cards.Count);
        Assert.True(viewModel.Cards[0].InstallRuntimeCommand.CanExecute(null));
        Assert.False(viewModel.Cards[1].InstallRuntimeCommand.CanExecute(null));
        Assert.Equal("检测完成", viewModel.Message);
    }

    [Fact]
    public async Task ChooseAndClearLocation_UseSoftwareServiceThenRefresh()
    {
        var service = new FakeSoftwareManagementService(
            Snapshot("origin", "Origin", available: false));
        using var viewModel = new SoftwarePageViewModel(service);
        viewModel.ChooseLocationRequested += (_, _, _) => @"C:\Origin\Origin.exe";
        await viewModel.RefreshAsync();
        var card = Assert.Single(viewModel.Cards);

        card.ChooseLocationCommand.Execute(null);
        await WaitUntilAsync(() => service.SavedPath is not null);
        await WaitUntilAsync(() => !viewModel.IsBusy);

        Assert.Equal(("origin", @"C:\Origin\Origin.exe"), service.SavedPath);
        Assert.Equal("应用位置已保存", viewModel.Message);

        card.ClearLocationCommand.Execute(null);
        await WaitUntilAsync(() => service.ClearedId is not null);
        await WaitUntilAsync(() => !viewModel.IsBusy);
        Assert.Equal("origin", service.ClearedId);
    }

    [Fact]
    public async Task InstallRuntime_RequiresConfirmationAndReportsResult()
    {
        var service = new FakeSoftwareManagementService(
            Snapshot("blender", "Blender", available: true));
        using var viewModel = new SoftwarePageViewModel(service);
        viewModel.ConfirmInstallRequested += _ => true;
        await viewModel.RefreshAsync();

        viewModel.Cards[0].InstallRuntimeCommand.Execute(null);
        await WaitUntilAsync(() => service.InstallCount == 1);
        await WaitUntilAsync(() => !viewModel.IsBusy);

        Assert.Contains("安装完成", viewModel.Message);
        Assert.Equal("blender", service.InstalledId);
    }

    [Fact]
    public async Task CancelInstall_CancelsTheInFlightRuntimeOperation()
    {
        var service = new FakeSoftwareManagementService(
            Snapshot("origin", "Origin", available: true))
        {
            BlockInstall = true,
        };
        using var viewModel = new SoftwarePageViewModel(service);
        viewModel.ConfirmInstallRequested += _ => true;
        await viewModel.RefreshAsync();

        viewModel.Cards[0].InstallRuntimeCommand.Execute(null);
        await service.InstallStarted.Task.WaitAsync(TimeSpan.FromSeconds(2));

        Assert.True(viewModel.CancelInstallCommand.CanExecute(null));
        viewModel.CancelInstallCommand.Execute(null);
        await WaitUntilAsync(() => !viewModel.IsBusy);

        Assert.Equal("安装已取消，原运行环境保持不变。", viewModel.Message);
    }

    private static SoftwareManagementSnapshot Snapshot(
        string id,
        string displayName,
        bool available,
        bool active = false) =>
        new(
            id,
            displayName,
            SoftwarePathKind.Executable,
            "*.exe",
            available,
            available ? $@"C:\{displayName}\app.exe" : "未检测到应用位置",
            available ? "运行环境已安装" : "运行环境尚未安装",
            RuntimeInstalled: available,
            HasActiveJobs: active);

    private static async Task WaitUntilAsync(Func<bool> condition)
    {
        var deadline = DateTime.UtcNow.AddSeconds(2);
        while (!condition() && DateTime.UtcNow < deadline)
        {
            await Task.Delay(10);
        }
        Assert.True(condition());
    }

    private sealed class FakeSoftwareManagementService(
        params SoftwareManagementSnapshot[] snapshots) : ISoftwareManagementService
    {
        internal (string Id, string Path)? SavedPath { get; private set; }
        internal string? ClearedId { get; private set; }
        internal string? InstalledId { get; private set; }
        internal int InstallCount { get; private set; }
        internal bool BlockInstall { get; init; }
        internal TaskCompletionSource InstallStarted { get; } = new(
            TaskCreationOptions.RunContinuationsAsynchronously);

        public Task<IReadOnlyList<SoftwareManagementSnapshot>> RefreshAsync(
            CancellationToken cancellationToken) =>
            Task.FromResult<IReadOnlyList<SoftwareManagementSnapshot>>(snapshots);

        public void SaveLocation(string softwareId, string path) =>
            SavedPath = (softwareId, path);

        public void ClearLocation(string softwareId) => ClearedId = softwareId;

        public async Task<RuntimeInstallResult> InstallRuntimeAsync(
            string softwareId,
            IProgress<string> progress,
            CancellationToken cancellationToken)
        {
            InstallCount++;
            InstalledId = softwareId;
            InstallStarted.TrySetResult();
            progress.Report("正在安装…");
            if (BlockInstall)
            {
                await Task.Delay(Timeout.InfiniteTimeSpan, cancellationToken);
            }
            return new RuntimeInstallResult(@"C:\runtime\python.exe", "安装完成");
        }
    }
}