DodoSSH/tests/DodoSSH.Client.App.Tests/ShellFlowTests.Forwards.cs

using DodoSSH.Client.Domain;
using DodoSSH.Client.Shell.ViewModels;
using DodoSSH.Client.Ssh;

namespace DodoSSH.Client.App.Tests;

/// <summary>
/// Port forwards, from the host editor that saves them to the tab they run on.
/// </summary>
/// <remarks>
/// The listeners here are fakes; <c>PortForwardTests</c> in the SSH suite carries real bytes through all
/// three kinds against a real sshd. What this holds is everything around them: which forwards start, on
/// which session, what a refusal looks like, and that none of it outlives the session.
/// </remarks>
public sealed partial class ShellFlowTests
{
    [Fact]
    public async Task AHostsForwards_StartWithItsTerminal_AndAreCountedInTheStatusBar()
    {
        var vault = await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        tab.IsLive.ShouldBeTrue();

        await EventuallyAsync(() => tab.ListeningForwardCount == 2, "both forwards should be listening");

        tab.Forwards.Select(row => row.Notation).ShouldBe(["-L 5432:db.internal:5432", "-D 1080"]);
        tab.ForwardsSummary.ShouldBe("⇄ 2 FORWARDS");

        ssh.Forwards.Select(forward => forward.Spec).ShouldBe(
        [
            new SshPortForwardSpec(SshPortForwardKind.Local, 5432, "db.internal", 5432),
            new SshPortForwardSpec(SshPortForwardKind.Dynamic, 1080),
        ]);

        vault.SelectedHost.ShouldNotBeNull().HasForwards.ShouldBeTrue();
    }

    [Fact]
    public async Task AForwardThatCannotStart_SaysWhy_AndStopsNothingElse()
    {
        ssh.ForwardFailure = spec => spec.BindPort == 5432 ? "Port 5432 on this machine is already in use." : null;

        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();

        await EventuallyAsync(() => tab.Forwards.All(row => row.State is not PortForwardState.Starting), "both should settle");

        var refused = tab.Forwards[0];
        refused.State.ShouldBe(PortForwardState.Failed);
        refused.StateText.ShouldBe("FAILED");
        refused.Detail.ShouldBe("Port 5432 on this machine is already in use.");

        tab.Forwards[1].IsListening.ShouldBeTrue();
        tab.IsLive.ShouldBeTrue("a forward that cannot start is not a reason to lose the shell");
        tab.ForwardsSummary.ShouldBe("⇄ 1 FORWARD");

        // The switch on a failed row is a retry, and the port has been freed since.
        ssh.ForwardFailure = null;
        await refused.ToggleCommand.ExecuteAsync(null);

        refused.IsListening.ShouldBeTrue();
        refused.Detail.ShouldBeNull();
    }

    [Fact]
    public async Task AForwardCanBeSwitchedOffAndOnAgain_WithoutTouchingTheSession()
    {
        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        await EventuallyAsync(() => tab.ListeningForwardCount == 2, "both forwards should be listening");

        var row = tab.Forwards[0];
        var first = ssh.Forwards[0];

        await row.ToggleCommand.ExecuteAsync(null);

        row.State.ShouldBe(PortForwardState.Stopped);
        first.IsDisposed.ShouldBeTrue("switching off is what stops the listener");
        tab.ForwardsSummary.ShouldBe("⇄ 1 FORWARD");

        await row.ToggleCommand.ExecuteAsync(null);

        row.IsListening.ShouldBeTrue();
        ssh.Forwards.Count.ShouldBe(3, "a restart is a new listener on the same session");
        tab.IsLive.ShouldBeTrue();
    }

    [Fact]
    public async Task AFailedConnectionThroughAForward_IsShownUnderIt_WhileItKeepsListening()
    {
        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        await EventuallyAsync(() => tab.ListeningForwardCount == 2, "both forwards should be listening");

        ssh.Forwards[0].Fail("Connection refused");

        tab.Forwards[0].Detail.ShouldBe("Connection refused");
        tab.Forwards[0].IsListening.ShouldBeTrue();
    }

    [Fact]
    public async Task WhenTheSessionEnds_ItsForwardsSayTheyWentWithIt()
    {
        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        await EventuallyAsync(() => tab.ListeningForwardCount == 2, "both forwards should be listening");

        ssh.Shells.ShouldHaveSingleItem().Drop("An established connection was aborted by the server.");

        await EventuallyAsync(() => !tab.IsLive, "the dropped shell should have ended the session");

        // Waited for in its own right rather than taken as read from IsLive. Ended clears IsLive and then
        // ends the forwards in the same dispatcher turn, which the app's UI thread never splits — but this
        // harness's post runs the ending on the fake shell's thread, so a poll from here can land between.
        await EventuallyAsync(
            () => tab.Forwards.All(row => row.Detail == "Stopped with the session."),
            "the session's end should have reached its forwards");

        tab.Forwards.ShouldAllBe(row => row.State == PortForwardState.Stopped);
        tab.Forwards.ShouldAllBe(row => row.Detail == "Stopped with the session.");
        tab.Forwards.ShouldAllBe(row => !row.CanToggle);
        tab.ForwardsSummary.ShouldBeNull();
        ssh.Forwards.ShouldAllBe(forward => forward.IsDisposed);
    }

    [Fact]
    public async Task AReconnect_StartsTheForwardsAgainOnTheNewSession()
    {
        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        await EventuallyAsync(() => tab.ListeningForwardCount == 2, "both forwards should be listening");

        var before = tab.Forwards.ToList();

        ssh.Shells[0].Drop("An established connection was aborted by the server.");
        await EventuallyAsync(() => !tab.IsLive, "the dropped shell should have ended the session");

        await shell.ReconnectTabCommand.ExecuteAsync(tab);

        await EventuallyAsync(() => tab.IsLive && tab.ListeningForwardCount == 2, "the new session's forwards should listen");

        tab.Forwards.ShouldNotContain(before[0], "a reconnect is a new session, with new rows");
        ssh.Forwards.Count.ShouldBe(4);
    }

    [Fact]
    public async Task ATypedInAddress_StartsNoForwards()
    {
        await ReadyToConnectAsync();

        await using var renderer = await FakeRenderer.AttachAsync(workspace, Token);

        await ConnectAtThePromptAsync("deploy@10.0.0.9", "hunter2");

        shell.Tabs.ShouldHaveSingleItem().Forwards.ShouldBeEmpty();
        ssh.Forwards.ShouldBeEmpty();
    }

    // ---- The phone's sheet ----

    /// <remarks>
    /// The phone lists a tab's forwards in a sheet over the terminal, so it obeys the connect sheet's rules:
    /// it collapses the renderer while it is up, and leaving the terminal lowers it however it is left.
    /// </remarks>
    [Fact]
    public async Task TheForwardsSheet_HidesTheRenderer_AndLeavingTheTerminalLowersIt()
    {
        await ConnectedHostWithForwardsAsync();

        shell.SelectedTab.ShouldNotBeNull().HasForwards.ShouldBeTrue();

        shell.OpenForwardsSheetCommand.Execute(null);

        shell.IsForwardsSheetOpen.ShouldBeTrue();
        shell.IsTerminalShowing.ShouldBeFalse("the sheet draws over the renderer's rectangle");
        shell.IsTerminalSurface.ShouldBeTrue("the bar the sheet was raised from is on that surface");

        shell.CloseForwardsSheetCommand.Execute(null);

        shell.IsTerminalShowing.ShouldBeTrue();

        shell.OpenForwardsSheetCommand.Execute(null);
        shell.ShowScreenCommand.Execute(ShellScreen.Keychain);

        shell.IsForwardsSheetOpen.ShouldBeFalse("a sheet left up over a page would hold the renderer blank");

        shell.OpenForwardsSheetCommand.Execute(null);

        shell.IsForwardsSheetOpen.ShouldBeFalse("it must not open over a page either");
    }

    /// <remarks>
    /// What the phone's bar button and its keep-alive notification read: whether a tab has forwards, whether
    /// one failed, and how many listen across every tab — with an event each time any of that moves.
    /// </remarks>
    [Fact]
    public async Task TheCountsAPhoneShows_FollowEveryForwardsState()
    {
        ssh.ForwardFailure = spec => spec.BindPort == 5432 ? "Port 5432 on this machine is already in use." : null;

        var changes = 0;
        shell.ForwardsChanged += (_, _) => changes++;

        await ConnectedHostWithForwardsAsync();

        var tab = shell.Tabs.ShouldHaveSingleItem();
        await EventuallyAsync(() => tab.Forwards.All(row => row.State is not PortForwardState.Starting), "both should settle");

        tab.HasForwards.ShouldBeTrue();
        tab.HasFailedForward.ShouldBeTrue();
        tab.HasListeningForward.ShouldBeTrue();
        shell.ListeningForwardCount.ShouldBe(1);
        changes.ShouldBeGreaterThan(0);

        var before = changes;
        ssh.ForwardFailure = null;
        await tab.Forwards[0].ToggleCommand.ExecuteAsync(null);

        tab.HasFailedForward.ShouldBeFalse();
        shell.ListeningForwardCount.ShouldBe(2);
        changes.ShouldBeGreaterThan(before, "a retry that listens is a change the notification has to hear");

        ssh.Shells.ShouldHaveSingleItem().Drop("An established connection was aborted by the server.");
        await EventuallyAsync(() => !tab.IsLive, "the dropped shell should have ended the session");

        shell.ListeningForwardCount.ShouldBe(0);
        tab.HasListeningForward.ShouldBeFalse();
        tab.HasForwards.ShouldBeTrue("the rows stay, saying they went with the session");
    }

    // ---- The editor ----

    [Fact]
    public async Task TheEditor_RefusesASecondListenerOnAPortThisHostAlreadyListensOn()
    {
        var vault = await ReadyToConnectAsync();

        vault.EditSelectedHostCommand.Execute(null);

        AddForward(vault, PortForwardKind.Local, "8080", "web.internal:80");
        AddForward(vault, PortForwardKind.Dynamic, "8080", string.Empty);

        vault.Status.ShouldBe("This host already has a forward listening on port 8080 here.");
        vault.EditorPortForwards.Count.ShouldBe(1);

        // A remote forward listens on the remote, whose ports are a different set.
        AddForward(vault, PortForwardKind.Remote, "8080", "localhost:3000");

        vault.EditorPortForwards.Count.ShouldBe(2);
    }

    [Theory]
    [InlineData("", "db:5432", "A forward needs a listening port, as a number.")]
    [InlineData("-1", "db:5432", "A forward needs a listening port, as a number.")]
    [InlineData("70000", "db:5432", "A forward's listening port must be between 1 and 65535, not 70000.")]
    [InlineData("5432", "db", "A forward's target is host:port, for example db.internal:5432.")]
    [InlineData("5432", "::1:5432", "A forward's target is host:port, for example db.internal:5432.")]
    [InlineData("5432", "db:0", "A forward's target port must be between 1 and 65535, not 0.")]
    public async Task TheEditor_RefusesAnUnusableForwardAtTheBox(string bindPort, string target, string expected)
    {
        var vault = await ReadyToConnectAsync();

        vault.EditSelectedHostCommand.Execute(null);

        AddForward(vault, PortForwardKind.Local, bindPort, target);

        vault.Status.ShouldBe(expected);
        vault.EditorPortForwards.ShouldBeEmpty();
    }

    [Theory]
    [InlineData("db.internal:5432", "db.internal", 5432)]
    [InlineData(" localhost:3000 ", "localhost", 3000)]
    [InlineData("[::1]:5432", "::1", 5432)]
    [InlineData("10.0.0.9:22", "10.0.0.9", 22)]
    public void AForwardTarget_IsReadAsHostColonPort(string text, string host, int port)
    {
        VaultViewModel.TryParseForwardTarget(text, out var parsedHost, out var parsedPort).ShouldBeTrue();

        parsedHost.ShouldBe(host);
        parsedPort.ShouldBe(port);
    }

    [Fact]
    public async Task EditingAHost_KeepsItsForwardsIds_SoTheMergeSeesAnEditNotANewForward()
    {
        var vault = await ReadyToConnectAsync();

        vault.EditSelectedHostCommand.Execute(null);
        AddForward(vault, PortForwardKind.Local, "5432", "db.internal:5432");
        await vault.SaveHostCommand.ExecuteAsync(null);

        var saved = vault.Hosts[0].Host.PortForwards.ShouldHaveSingleItem();

        vault.SelectedHost = vault.Hosts[0];
        vault.EditSelectedHostCommand.Execute(null);
        vault.EditorNotes = "primary";
        await vault.SaveHostCommand.ExecuteAsync(null);

        vault.Hosts[0].Host.PortForwards.ShouldHaveSingleItem().ShouldBe(saved);
    }

    /// <summary>
    /// A host with a bound key and two forwards — one local, one SOCKS — connected, with its tab selected.
    /// </summary>
    private async Task<VaultViewModel> ConnectedHostWithForwardsAsync()
    {
        var vault = await ReadyToConnectAsync();

        await AddKeyAsync(vault, "deploy");
        await BindKeyAsync(vault, vault.Hosts[0], vault.Keys[0].EntityId);

        vault.EditSelectedHostCommand.Execute(null);
        AddForward(vault, PortForwardKind.Local, "5432", "db.internal:5432");
        AddForward(vault, PortForwardKind.Dynamic, "1080", string.Empty);
        vault.EditorPortForwards.Count.ShouldBe(2, vault.Status);
        await vault.SaveHostCommand.ExecuteAsync(null);

        await using var renderer = await FakeRenderer.AttachAsync(workspace, Token);

        vault.ChooseHostCommand.Execute(Host(vault, "prod-db"));
        await vault.ConnectToChosenHostCommand.ExecuteAsync(null);

        return vault;
    }

    private static void AddForward(VaultViewModel vault, PortForwardKind kind, string bindPort, string target)
    {
        vault.EditorNewForwardKind = (int)kind;
        vault.EditorNewForwardBindPort = bindPort;
        vault.EditorNewForwardTarget = target;
        vault.AddEditorForwardCommand.Execute(null);
    }
}