﻿/*
 * 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.
 */

namespace DotPulsar.Internal
{
    using Abstractions;
    using DotPulsar.Internal.Extensions;
    using PulsarApi;
    using System;
    using System.Threading;
    using System.Threading.Tasks;

    public sealed class ProducerChannelFactory : IProducerChannelFactory
    {
        private readonly Guid _correlationId;
        private readonly IRegisterEvent _eventRegister;
        private readonly IConnectionPool _connectionPool;
        private readonly CommandProducer _commandProducer;
        private readonly ICompressorFactory? _compressorFactory;
        private readonly Schema? _schema;

        public ProducerChannelFactory(
            Guid correlationId,
            IRegisterEvent eventRegister,
            IConnectionPool connectionPool,
            string topic,
            string? producerName,
            SchemaInfo schemaInfo,
            ICompressorFactory? compressorFactory)
        {
            _correlationId = correlationId;
            _eventRegister = eventRegister;
            _connectionPool = connectionPool;

            _commandProducer = new CommandProducer
            {
                ProducerName = producerName,
                Topic = topic
            };

            _compressorFactory = compressorFactory;
            _schema = schemaInfo.PulsarSchema;
        }

        public async Task<IProducerChannel> Create(CancellationToken cancellationToken)
        {
            var connection = await _connectionPool.FindConnectionForTopic(_commandProducer.Topic, cancellationToken).ConfigureAwait(false);
            var channel = new Channel(_correlationId, _eventRegister, new AsyncQueue<MessagePackage>());
            var response = await connection.Send(_commandProducer, channel, cancellationToken).ConfigureAwait(false);
            var schemaVersion = await GetSchemaVersion(connection, cancellationToken).ConfigureAwait(false);
            return new ProducerChannel(response.ProducerId, response.ProducerName, connection, _compressorFactory, schemaVersion);
        }

        private async ValueTask<byte[]?> GetSchemaVersion(IConnection connection, CancellationToken cancellationToken)
        {
            if (_schema is null || _schema.Type == Schema.SchemaType.None)
                return null;

            var command = new CommandGetOrCreateSchema
            {
                Schema = _schema,
                Topic = _commandProducer.Topic
            };

            var response = await connection.Send(command, cancellationToken).ConfigureAwait(false);

            response.Expect(BaseCommand.Type.GetOrCreateSchemaResponse);
            if (response.GetOrCreateSchemaResponse.ShouldSerializeErrorCode())
                response.GetOrCreateSchemaResponse.Throw();

            return response.GetOrCreateSchemaResponse.SchemaVersion;
        }
    }
}