using System.Runtime.InteropServices;
using CursorLang.Core.Interop;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;

namespace CursorLang.Core.Services;

/// <summary>
/// Whether Windows started the application by itself.
/// </summary>
/// <remarks>
/// A launch of its own accord ends up in the tray without a window: the user asked
/// for the application to be there when they sign in, not for a window to greet them
/// every morning. A launch by the user is another matter — the window is what they
/// clicked for.
///
/// The two builds tell the launches apart differently. A build in a folder is
/// started from the registry, and the command written there carries an argument of
/// its own — see <see cref="RegistryStartup"/>. A package has no say in its command
/// line, and Windows is asked about the activation instead.
/// </remarks>
internal static class StartupLaunch
{
    /// <summary>What the registry entry adds to the path of the application.</summary>
    internal const string Argument = "--startup";

    /// <summary>Whether this launch is the doing of Windows rather than of the user.</summary>
    internal static bool IsAutomatic(IReadOnlyList<string> arguments) =>
        HasArgument(arguments) || IsStartupActivation();

    /// <summary>The command line says the launch comes from the startup entry.</summary>
    internal static bool HasArgument(IReadOnlyList<string> arguments) =>
        arguments.Any(argument => string.Equals(argument, Argument, StringComparison.OrdinalIgnoreCase));

    private static bool IsStartupActivation()
    {
        if (!PackageIdentityNative.IsPackaged)
        {
            return false;
        }

        try
        {
            return AppInstance.GetActivatedEventArgs() is { Kind: ActivationKind.StartupTask };
        }
        catch (Exception e) when (e is COMException or InvalidOperationException or NotSupportedException)
        {
            // Windows has nothing to say about the activation. A window shown when it
            // was not asked for is a smaller mishap than an application that hides
            // when the user has just started it
            return false;
        }
    }
}