//-----------------------------------------------------------------------------
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------
 
namespace System.ServiceModel.Channels
{
    using System.Collections.Generic;
    using System.Runtime;
 
    public class CorrelationDataMessageProperty : IMessageProperty
    {
        const string PropertyName = "CorrelationDataMessageProperty";
        Dictionary<string, DataProviderEntry> dataProviders;
 
        public CorrelationDataMessageProperty()
        {
        }
 
        CorrelationDataMessageProperty(IDictionary<string, DataProviderEntry> dataProviders)
        {
            if (dataProviders != null && dataProviders.Count > 0)
            {
                this.dataProviders = new Dictionary<string, DataProviderEntry>(dataProviders);
            }
        }
 
        public static string Name
        {
            get { return PropertyName; }
        }
 
        public void Add(string name, Func<string> dataProvider)
        {
            if (string.IsNullOrEmpty(name))
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("name");
            }
 
            if (dataProvider == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("dataProvider");
            }
 
            if (this.dataProviders == null)
            {
                this.dataProviders = new Dictionary<string, DataProviderEntry>();
            }
            this.dataProviders.Add(name, new DataProviderEntry(dataProvider));
        }
 
        public bool Remove(string name)
        {
            if (this.dataProviders != null)
            {
                return this.dataProviders.Remove(name);
            }
            else
            {
                return false;
            }
        }
 
        public bool TryGetValue(string name, out string value)
        {
            DataProviderEntry entry;
            if (this.dataProviders != null && this.dataProviders.TryGetValue(name, out entry))
            {
                value = entry.Data;
                return true;
            }
            else
            {
                value = null;
                return false;
            }
        }
 
        public static bool TryGet(Message message, out CorrelationDataMessageProperty property)
        {
            if (message == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("message");
            }
            return TryGet(message.Properties, out property);
        }
 
        public static bool TryGet(MessageProperties properties, out CorrelationDataMessageProperty property)
        {
            object value = null;
            if (properties.TryGetValue(PropertyName, out value))
            {
                property = value as CorrelationDataMessageProperty;
            }
            else
            {
                property = null;
            }
            return property != null;
        }
 
        public static void AddData(Message message, string name, Func<string> dataProvider)
        {
            if (string.IsNullOrEmpty(name))
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("name");
            }
 
            if (dataProvider == null)
            {
                throw DiagnosticUtility.ExceptionUtility.ThrowHelperArgumentNull("dataProvider");
            }
 
            CorrelationDataMessageProperty data = null;
            object value = null;
            if (message.Properties.TryGetValue(PropertyName, out value))
            {
                data = value as CorrelationDataMessageProperty;
            }
 
            bool addNewProperty = false;
            if (data == null)
            {
                data = new CorrelationDataMessageProperty();
                addNewProperty = true;
            }
 
            data.Add(name, dataProvider);
 
            if (addNewProperty)
            {
                message.Properties[PropertyName] = data;
            }
        }
 
        public IMessageProperty CreateCopy()
        {
            return new CorrelationDataMessageProperty(this.dataProviders);
        }
 
        class DataProviderEntry
        {
            string resolvedData;
            Func<string> dataProvider;
 
            public DataProviderEntry(Func<string> dataProvider)
            {
                Fx.Assert(dataProvider != null, "dataProvider required");
                this.dataProvider = dataProvider;
                this.resolvedData = null;
            }
 
            public string Data
            {
                get
                {
                    if (this.dataProvider != null)
                    {
                        this.resolvedData = this.dataProvider();
                        this.dataProvider = null;
                    }
 
                    return this.resolvedData;
                }
            }
        }
    }
}