using ClaudeDo.Ui.ViewModels;
using Xunit;

namespace ClaudeDo.Ui.Tests.ViewModels.MissionControl;

public class InteractiveTerminalViewModelTests
{
    private static readonly DateTime LaunchedAt = new(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);

    // ── Died-at-startup detection (fix: an immediate ConPTY exit left StartError null, so
    //    ConPtyPaneViewModel.CanRetry — which requires StartError — never offered Retry) ────────

    [Fact]
    public void ProcessExitsNonzero_RightAfterLaunch_SetsStartError()
    {
        using var terminal = new InteractiveTerminalViewModel(() => LaunchedAt);
        terminal.IsRunning = true; // simulates a successful ConPTY spawn

        terminal.OnSessionProcessExited(null, 1);

        Assert.False(terminal.IsRunning);
        Assert.True(terminal.HasExited);
        Assert.Equal(1, terminal.ExitCode);
        Assert.NotNull(terminal.StartError);
    }

    [Fact]
    public void ProcessExitsNonzero_AfterRunningAWhile_DoesNotSetStartError()
    {
        var exitedAt = LaunchedAt.AddSeconds(10);
        var callCount = 0;
        using var terminal = new InteractiveTerminalViewModel(() => callCount++ == 0 ? LaunchedAt : exitedAt);
        terminal.IsRunning = true; // records LaunchedAt via the first clock call

        terminal.OnSessionProcessExited(null, 1); // crash after running for a while

        Assert.True(terminal.HasExited);
        Assert.Null(terminal.StartError);
        Assert.True(terminal.HasExitedAfterStartup); // no StartError banner, so the host needs this signal instead
    }

    [Fact]
    public void ProcessExitsZero_RightAfterLaunch_DoesNotSetStartError()
    {
        using var terminal = new InteractiveTerminalViewModel(() => LaunchedAt);
        terminal.IsRunning = true;

        terminal.OnSessionProcessExited(null, 0); // user typed exit / session ended cleanly

        Assert.True(terminal.HasExited);
        Assert.Null(terminal.StartError);
        Assert.True(terminal.HasExitedAfterStartup);
    }

    // ── HasExitedAfterStartup (drives the host's "session ended" banner — every death that
    //    ISN'T already covered by StartError) ─────────────────────────────────────────────────

    [Fact]
    public void FreshTerminal_HasExitedAfterStartupIsFalse()
    {
        using var terminal = new InteractiveTerminalViewModel(() => LaunchedAt);

        Assert.False(terminal.HasExitedAfterStartup);
    }

    [Fact]
    public void ProcessExitsNonzero_WithinGraceWindow_HasExitedAfterStartupIsFalse()
    {
        using var terminal = new InteractiveTerminalViewModel(() => LaunchedAt);
        terminal.IsRunning = true;

        terminal.OnSessionProcessExited(null, 1); // startup failure — StartError covers it instead

        Assert.NotNull(terminal.StartError);
        Assert.False(terminal.HasExitedAfterStartup);
    }

    // ── ExitedAfterStartup (a session that ran, then broke -- used to be a silent dead tile;
    //    the worker turns it into a usage-limit auto-restart for list handlers) ───────────────────

    [Fact]
    public void ProcessExitsNonzero_AfterRunningAWhile_RaisesExitedAfterStartup()
    {
        using var terminal = NewTerminalExitingAfter(TimeSpan.FromMinutes(90));
        int? reported = null;
        terminal.ExitedAfterStartup += code => reported = code;

        terminal.OnSessionProcessExited(null, 1);

        Assert.Equal(1, reported);
    }

    [Fact]
    public void ProcessExitsNonzero_WithinGraceWindow_DoesNotRaiseExitedAfterStartup()
    {
        using var terminal = new InteractiveTerminalViewModel(() => LaunchedAt);
        terminal.IsRunning = true;
        var raised = false;
        terminal.ExitedAfterStartup += _ => raised = true;

        terminal.OnSessionProcessExited(null, 1);

        Assert.False(raised);
        Assert.NotNull(terminal.StartError); // still the startup-failure banner
    }

    [Fact]
    public void ProcessExitsZero_AfterRunningAWhile_DoesNotRaiseExitedAfterStartup()
    {
        using var terminal = NewTerminalExitingAfter(TimeSpan.FromMinutes(90));
        var raised = false;
        terminal.ExitedAfterStartup += _ => raised = true;

        terminal.OnSessionProcessExited(null, 0);

        Assert.False(raised);
    }

    private static InteractiveTerminalViewModel NewTerminalExitingAfter(TimeSpan uptime)
    {
        var callCount = 0;
        var terminal = new InteractiveTerminalViewModel(
            () => callCount++ == 0 ? LaunchedAt : LaunchedAt + uptime);
        terminal.IsRunning = true; // records LaunchedAt via the first clock call
        return terminal;
    }

    // ── Paste/drop failure reporting (fix: PasteAsync used to swallow every exception and return
    //    void, so a failed Ctrl+V or file drop gave the user no signal at all) ────────────────────

    [Fact]
    public async Task PasteAsync_ReturnsFalse_WhenSessionNotRunning()
    {
        using var terminal = new InteractiveTerminalViewModel();

        Assert.False(await terminal.PasteAsync());
    }

    [Fact]
    public async Task SendTextAsync_ReturnsFalse_WhenSessionNotRunning()
    {
        using var terminal = new InteractiveTerminalViewModel();

        Assert.False(await terminal.SendTextAsync("dropped/path"));
    }

    [Fact]
    public void ReportSendFailed_RaisesErrorReported()
    {
        using var terminal = new InteractiveTerminalViewModel();
        string? error = null;
        terminal.ErrorReported += msg => error = msg;

        terminal.ReportSendFailed();

        Assert.NotNull(error);
    }
}