Notification.cs

using System.Diagnostics;

namespace NotifysendSharp;

public class Notification
{
    static (string[] Arguments, Dictionary<string, Func<CancellationToken, Task>> ButtonCallbacks) CompileArguments(NotificationOptions options)
    {
        List<string> args = [];

        if (options.Urgency.HasValue) args.Add(Utils.Escape($"--urgency={options.Urgency.Value switch
        {
            NotificationUrgency.Low => "low",
            NotificationUrgency.Normal => "normal",
            NotificationUrgency.Critical => "critical",
            _ => throw new NotImplementedException(),
        }}"));
        if (options.ExpireTime.HasValue) args.Add(Utils.Escape($"--expire-time={options.ExpireTime.Value.TotalMilliseconds}"));
        if (!string.IsNullOrWhiteSpace(options.AppName)) args.Add(Utils.Escape($"--app-name={options.AppName}"));
        if (!string.IsNullOrWhiteSpace(options.AppIcon)) args.Add(Utils.Escape($"--app-icon={options.AppIcon}"));
        if (!string.IsNullOrWhiteSpace(options.Icon)) args.Add(Utils.Escape($"--icon={options.Icon}"));
        if (options.Category is not null) args.Add(Utils.Escape($"--category={string.Join(',', options.Category)}"));
        if (options.Transient) args.Add($"--transient");
        if (options.Wait) args.Add($"--wait");

        Dictionary<string, Func<CancellationToken, Task>> buttonCallbacks = [];

        if (options.Buttons is not null && options.Buttons.Count > 0)
        {
            foreach (NotificationButton button in options.Buttons)
            {
                string key = Utils.GetNonce(buttonCallbacks.Count + 1);
                buttonCallbacks.Add(key, button.Callback);
                args.Add(Utils.Escape($"--action={key}={button.Label}"));
            }
        }

        args.Add(Utils.Escape(options.Title));
        if (!string.IsNullOrWhiteSpace(options.Body)) args.Add(Utils.Escape(options.Body));

        return (args.ToArray(), buttonCallbacks);
    }

    public static async Task Send(NotificationOptions options, CancellationToken cancellationToken = default)
    {
        (string[] args, Dictionary<string, Func<CancellationToken, Task>> buttonCallbacks) = CompileArguments(options);

        Process process = Process.Start(new ProcessStartInfo()
        {
            FileName = "notify-send",
            Arguments = string.Join(' ', args),
            RedirectStandardOutput = true,
            UseShellExecute = false,
        }) ?? throw new Exception($"Failed to start notify-send");

        await process.WaitForExitAsync(cancellationToken).ContinueWith(_ => process.Kill(), cancellationToken);

        string choice = process.StandardOutput.ReadToEnd().Trim();
        if (buttonCallbacks.TryGetValue(choice, out Func<CancellationToken, Task>? callback))
        {
            await callback.Invoke(cancellationToken);
        }
    }
}