dotnet add package Microsoft.Orleans.Reminders.DynamoDB

using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Orleans.Configuration;
using Orleans.Hosting;

var builder = Host.CreateApplicationBuilder(args)
    .UseOrleans(siloBuilder =>
    {
        siloBuilder
            .UseLocalhostClustering()
            // Configure DynamoDB as reminder storage
            .UseDynamoDBReminderService(options =>
            {
                options.AccessKey = "YOUR_AWS_ACCESS_KEY";
                options.SecretKey = "YOUR_AWS_SECRET_KEY";
                options.Region = "us-east-1";
                options.TableName = "OrleansReminders";
                options.CreateIfNotExists = true;
            });
    });

// Run the host
var host = builder.Build();
await host.StartAsync();

// Get a reference to the grain
var reminderGrain = host.Services.GetRequiredService<IGrainFactory>()
    .GetGrain<IReminderGrain>("my-reminder-grain");

// Start the reminder
await reminderGrain.StartReminder("ExampleReminder");
Console.WriteLine("Reminder started!");

// Keep the host running until the application is shut down
await host.WaitForShutdownAsync();

using System;
using System.Threading.Tasks;
using Orleans;
using Orleans.Runtime;

namespace ReminderExample;

public interface IReminderGrain : IGrainWithStringKey
{
    Task StartReminder(string reminderName);
    Task StopReminder();
}

public class ReminderGrain : Grain, IReminderGrain, IRemindable
{
    private string _reminderName = "MyReminder";

    public async Task StartReminder(string reminderName)
    {
        _reminderName = reminderName;
        
        // Register a persistent reminder
        await RegisterOrUpdateReminder(
            reminderName,
            TimeSpan.FromMinutes(2),  // Time to delay before the first tick (must be > 1 minute)
            TimeSpan.FromMinutes(5)); // Period of the reminder (must be > 1 minute)
    }

    public async Task StopReminder()
    {
        // Find and unregister the reminder
        var reminder = await GetReminder(_reminderName);
        if (reminder != null)
        {
            await UnregisterReminder(reminder);
        }
    }

    public Task ReceiveReminder(string reminderName, TickStatus status)
    {
        // This method is called when the reminder ticks
        Console.WriteLine($"Reminder {reminderName} triggered at {DateTime.UtcNow}. Status: {status}");
        return Task.CompletedTask;
    }
}