SniffableLedger.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Waher.Networking;
using Waher.Networking.Sniffers;
using Waher.Persistence;
 
namespace Waher.IoTGateway.Setup.Databases.Sniffing
{
    public class SniffableLedger : CommunicationLayer
    {
        private bool prevHasSniffers = false;
 
        public SniffableLedger()
            : base(false)
        {
        }
 
        public override void Add(ISniffer Sniffer)
        {
            base.Add(Sniffer);
            this.CheckEventHandlers();
        }
 
        public override void AddRange(IEnumerable<ISniffer> Sniffers)
        {
            base.AddRange(Sniffers);
            this.CheckEventHandlers();
        }
 
        public override bool Remove(ISniffer Sniffer)
        {
            bool Result = base.Remove(Sniffer);
            this.CheckEventHandlers();
            return Result;
        }
 
        private void CheckEventHandlers()
        {
            bool b = this.HasSniffers;
 
            if (this.prevHasSniffers != b)
            {
                if (b)
                {
                    Ledger.CollectionCleared += this.Ledger_CollectionCleared;
                    Ledger.EntryAdded += this.Ledger_EntryAdded;
                    Ledger.EntryUpdated += this.Ledger_EntryUpdated;
                    Ledger.EntryDeleted += this.Ledger_EntryDeleted;
                }
                else
                {
                    Ledger.CollectionCleared -= this.Ledger_CollectionCleared;
                    Ledger.EntryAdded -= this.Ledger_EntryAdded;
                    Ledger.EntryUpdated -= this.Ledger_EntryUpdated;
                    Ledger.EntryDeleted -= this.Ledger_EntryDeleted;
                }
 
                this.prevHasSniffers = b;
            }
        }
 
        private async void Ledger_EntryAdded(object Sender, ObjectEventArgs e)
        {
            try
            {
                await this.TransmitText(await SniffableDatabase.GetJSON(e.Object));
            }
            catch (Exception)
            {
                await this.TransmitText("Entry of type " + e.Object.GetType().FullName + " added.");
            }
        }
 
        private async void Ledger_EntryUpdated(object Sender, ObjectEventArgs e)
        {
            try
            {
                await this.ReceiveText(await SniffableDatabase.GetJSON(e.Object));
            }
            catch (Exception)
            {
                await this.ReceiveText("Entry of type " + e.Object.GetType().FullName + " updated.");
            }
        }
 
        private async void Ledger_EntryDeleted(object Sender, ObjectEventArgs e)
        {
            try
            {
                await this.Error(await SniffableDatabase.GetJSON(e.Object));
            }
            catch (Exception)
            {
                await this.Error("Entry of type " + e.Object.GetType().FullName + " deleted.");
            }
        }
 
        private Task Ledger_CollectionCleared(object Sender, CollectionEventArgs e)
        {
            return this.Information("Collection has been cleared: " + e.Collection);
        }
    }
}