﻿/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using DotPulsar;
using DotPulsar.Abstractions;
using DotPulsar.Extensions;
using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Producing
{
    class Program
    {
        static async Task Main(string[] args)
        {
            const string myTopic = "persistent://public/default/mytopic";

            await using var client = PulsarClient.Builder().Build(); //Connecting to pulsar://localhost:6650

            var producer = client.NewProducer().Topic(myTopic).Create();

            var monitoring = Monitor(producer);

            var cts = new CancellationTokenSource();

            var producing = ProduceMessages(producer, cts.Token);

            Console.WriteLine("Press a key to exit");

            _ = Console.ReadKey();

            cts.Cancel();

            await producing;

            await producer.DisposeAsync();

            await monitoring;
        }

        private static async Task ProduceMessages(IProducer producer, CancellationToken cancellationToken)
        {
            await Task.Yield();

            var delay = TimeSpan.FromSeconds(5);

            try
            {
                while (!cancellationToken.IsCancellationRequested)
                {
                    var data = Encoding.UTF8.GetBytes("Sent " + DateTime.UtcNow.ToString());
                    _ = await producer.Send(data, cancellationToken);
                    await Task.Delay(delay);
                }
            }
            catch (OperationCanceledException) // If not using the cancellationToken, then just dispose the producer and catch ObjectDisposedException instead
            {
                return;
            }
        }

        private static async Task Monitor(IProducer producer)
        {
            await Task.Yield();

            var state = ProducerState.Disconnected;

            while (true)
            {
                state = await producer.StateChangedFrom(state);

                var stateMessage = state switch
                {
                    ProducerState.Connected => $"The producer is connected",
                    ProducerState.Disconnected => $"The producer is disconnected",
                    ProducerState.Closed => $"The producer has closed",
                    ProducerState.Faulted => $"The producer has faulted",
                    _ => $"The producer has an unknown state '{state}'"
                };

                Console.WriteLine(stateMessage);

                if (producer.IsFinalState(state))
                    return;
            }
        }
    }
}