/pServiceBus/Src/PServiceBus.RabbitMQ/Provider.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using RabbitMQ.Client;

using System.Text.RegularExpressions;

using RabbitMQ.Client.Exceptions;

using System.Runtime.Serialization.Formatters.Binary;

using System.IO;

using PServiceBus.Core.Runtime;

using PServiceBus.Core.Runtime.Extensions;

using PServiceBus.Core.Logger;

using PServiceBus.Core.Interface;

using System.Collections;

using System.Collections.Concurrent;



namespace PServiceBus.RabbitMQ {

    public sealed class Provider<TObject> : IHaveEndpoint, IObjectProvider<TObject> where TObject : class {

       

        private object _lockObject = new object();

        private static ConcurrentDictionary<string, IConnection> _connections = new ConcurrentDictionary<string, IConnection>();

        private static ConcurrentDictionary<string, IModel> _models = new ConcurrentDictionary<string, IModel>();

        private static ConcurrentDictionary<string, ProviderFactory> _factories = new ConcurrentDictionary<string, ProviderFactory>();

        private static ConcurrentDictionary<string, object> _providers = new ConcurrentDictionary<string, object>();





        public static Provider<TObject> GetProvider(string endpoint, bool appendTypeNameToEndpoint = false, string endpointAlias = null) {

            return _providers.GetOrAdd(endpoint, key => 

                new Provider<TObject> { Endpoint = endpoint, IDFunc = x => Guid.NewGuid(),

                    EndpointAlias = endpointAlias, AppendTypeNameToEndpoint = appendTypeNameToEndpoint }) as Provider<TObject>;

        }



        private void Query(Action<IModel, string, string> action) {

            lock (_lockObject) {

                var factory = ConnectionProviderFactory;

                CreateQueue(Model, factory.ExchangeName, factory.Queue);

                action(Model, factory.ExchangeName, factory.Queue);

            }

        }



        internal class ProviderFactory {

            public ConnectionFactory ConnectionFactory { get; set; }

            public string ExchangeName { get; set; }

            public string Queue { get; set; }

        }



        private IConnection GetConnection(string endpoint, bool appendTypeNameToEndpoint, string endpointAlias = null) {

            string key = String.Concat(endpoint, endpointAlias ?? string.Empty);

            var connection = _connections.GetOrAdd(key, k => {

                return GetConnectionFactory(Endpoint, AppendTypeNameToEndpoint, EndpointAlias).ConnectionFactory.CreateConnection();

            });

            if (connection == null || !connection.IsOpen)

                connection = _connections.AddOrUpdate(key, k => GetConnectionFactory(Endpoint, AppendTypeNameToEndpoint, EndpointAlias).ConnectionFactory.CreateConnection(),

                    (k, c) => GetConnectionFactory(Endpoint, AppendTypeNameToEndpoint, EndpointAlias).ConnectionFactory.CreateConnection());

            return connection;

        }



        private IModel GetModel(string endpoint, bool appendTypeNameToEndpoint, string endpointAlias = null) {

            string key = String.Concat(endpoint, endpointAlias ?? string.Empty);

            var model = _models.GetOrAdd(key, k => GetConnection(endpoint, appendTypeNameToEndpoint, endpointAlias).CreateModel());

            if(model == null || !model.IsOpen)

                model = _models.AddOrUpdate(key, k => GetConnection(endpoint, appendTypeNameToEndpoint, endpointAlias).CreateModel(),

                    (k, c) => GetConnection(endpoint, appendTypeNameToEndpoint, endpointAlias).CreateModel());

            return model;

        }



        private IConnection Connection {

            get { return GetConnection(Endpoint, AppendTypeNameToEndpoint, EndpointAlias); }

        }



        private IModel Model {

            get { return GetModel(Endpoint, AppendTypeNameToEndpoint, EndpointAlias); }

        }

        

        private ProviderFactory GetConnectionFactory(string endpoint, bool appendTypeNameToEndpoint, string endpointAlias = null) {

            var key = String.Concat(endpoint, endpointAlias ?? string.Empty);

            return _factories.GetOrAdd(key, k =>

            {

                var path = AppendTypeNameToEndpoint ? typeof(TObject).FullName.Replace(".", "_") : string.Empty;

                path += (EndpointAlias ?? string.Empty);

                endpoint += (endpoint.EndsWith("/") ? string.Empty : "/") + path;

                var uri = EndpointUri.Parse(endpoint);

                var queue = uri.Path;

                var exchangeName = "ex" + queue;

                var factory = new ConnectionFactory() { HostName = uri.Host, UserName = uri.Username, Password = uri.Password, Port = uri.Port };

                return new ProviderFactory() { ConnectionFactory = factory, ExchangeName = exchangeName, Queue = queue };

            });

        }



        private ProviderFactory ConnectionProviderFactory {

            get {

                return GetConnectionFactory(Endpoint, AppendTypeNameToEndpoint, EndpointAlias);

            }

        }





        public void Clear() {

            Query((ch, exchangeName, queue) => ch.QueuePurge(Endpoint));

        }



        

        private bool _queueCreated = false;

        private bool CreateQueue(IModel ch, string exchangeName, string queue) {

            var success = true;

            if (_queueCreated) return success;

            try {

                ch.ExchangeDeclare(exchangeName, ExchangeType.Fanout, true);

                ch.QueueDeclare(queue, true, false, false, null);

                ch.QueueBind(queue, exchangeName, queue, null);

                _queueCreated = true;

            } catch { success = false; }

            return success;

        }

        

        private TObject GetObjectByID(string id, bool deleteObjectOnRead) {

            var obj = default(TObject);

            try {

                lock (_lockObject) {

                    Query((ch, exchangeName, queue) =>

                    {

                        while (true) {

                            try {

                                var result = ch.BasicGet(queue, !deleteObjectOnRead);

                                if (result == null) break;

                                var body = result.Body.Deserialize<TObject>();

                                var prop = result.BasicProperties;

                                if (body != null && (id == null || (id != null && prop.MessageId == id))) {

                                    if (deleteObjectOnRead) ch.BasicAck(result.DeliveryTag, false);

                                    obj = body;

                                    break;

                                }

                            } catch (Exception) { break; }

                        }

                    });

                }

            }

            catch {

            }

            return obj;

        }



        #region IObjectProvider<TObject> Members



        public bool Refresh(TObject obj) {

            throw new NotImplementedException();

        }



        public bool Add(IEnumerable<TObject> list) {

            var success = true;

            try {

                Query((ch, exchangeName, queue) =>

                {

                    foreach (var data in list) {

                        var prop = ch.CreateBasicProperties();

                        prop.SetPersistent(true);

                        prop.DeliveryMode = 2;

                        prop.MessageId = IDFunc(data).ToString();

                        ch.BasicPublish(exchangeName, queue, prop, data.Serialize());

                    }

                });

            } catch {

                success = false;

            }

            return success;

        }



        public bool Add(TObject obj) {

            Query((ch, exchangeName, queue) =>

            {

                var prop = ch.CreateBasicProperties();

                prop.SetPersistent(true);

                prop.DeliveryMode = 2;

                prop.MessageId = IDFunc(obj).ToString();

                ch.BasicPublish(exchangeName, queue, prop, obj.Serialize());

            });

            return true;

        }



        public void Delete() {

            Query((ch, exchangeName, queue) =>

            {

                try {

                    ch.QueueUnbind(queue, exchangeName, queue, null);

                    ch.ExchangeDelete(exchangeName, true);

                    ch.QueueDelete(queue, true, false);

                } catch {

                    throw;

                }

            });

        }



        public bool Delete(IEnumerable<TObject> list) {

            var success = true;

            foreach (var obj in list) 

                success &= GetObjectByID(IDFunc(obj).ToString(), true) != null;

            return success;

        }



        public bool Delete(IEnumerable<Func<TObject, bool>> conditions) {

            var success = true;

            foreach (var condition in conditions) {

                var deleteObj = this.FirstOrDefault(obj => obj != null && condition(obj));

                success &= deleteObj != null

                    && GetObjectByID(IDFunc(deleteObj).ToString(), true) != null;

            }

            return success;

        }



        public bool Delete(Func<TObject, bool> condition) {

            var deleteObj = this.FirstOrDefault(obj => obj != null && condition(obj));

            return deleteObj != null

                && GetObjectByID(IDFunc(deleteObj).ToString(), true) != null;           

        }



        public bool Exists(Func<TObject, bool> condition) {

            return Get(condition) != null;

        }



        public TObject Get(Func<TObject, bool> condition) {

            return this.FirstOrDefault(obj => condition(obj));

        }



        public bool Exists(TObject obj) {

            return GetObjectByID(IDFunc(obj).ToString(), false) != null;

        }



        public TObject Get(Guid id) {

            return GetObjectByID(id.ToString(), false);

        }



        public bool Delete(TObject obj) {

            return GetObjectByID(IDFunc(obj).ToString(), true) != null;

        }



        public string Endpoint { get; set; }



        public string EndpointAlias { get; set; }



        public bool AppendTypeNameToEndpoint { get; set; }



        public bool DeleteObjectOnRead { get; set; }



        public Func<TObject, Guid> IDFunc { get; set; }

        #endregion



        #region IEnumerable<TObject> Members



        public IEnumerator<TObject> GetEnumerator() {

            var factory = ConnectionProviderFactory;

            CreateQueue(Model, factory.ExchangeName, factory.Queue);

            var body = default(TObject);

            

            while (true) {

                try {

                    var result = Model.BasicGet(factory.Queue, !DeleteObjectOnRead);

                    if (result != null)

                        MethodHelper.Try(() => body = result.Body.Deserialize<TObject>());

                    else break;

                    if (DeleteObjectOnRead) Model.BasicAck(result.DeliveryTag, false);

                } catch (Exception) { break; }

                if (body != null) yield return body;

            }

        }



        #endregion



        #region IEnumerable Members



        IEnumerator IEnumerable.GetEnumerator() {

            return GetEnumerator();

        }



        #endregion



        #region IDisposable Members



        public void Dispose() {

            MethodHelper.Try(() => {

                foreach (var kv in _models) kv.Value.Close();

            });

            MethodHelper.Try(() => {

                foreach (var kv in _connections) kv.Value.Close();

            });

            _models.Clear();

            _connections.Clear();

            _factories.Clear();

        }



        #endregion

    }

}