using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Threading;
using Microsoft.WindowsAzure;
using Microsoft.WindowsAzure.Diagnostics;
using Microsoft.WindowsAzure.ServiceRuntime;
using Microsoft.WindowsAzure.StorageClient;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.WindowsAzure.Autoscaling;
using HeuristicLab.Services.Optimization.Scaler.Hive;

namespace HeuristicLab.Services.Optimization.Scaler {
  public class WorkerRole : RoleEntryPoint {
    private const string WADConnectionString = "Microsoft.WindowsAzure.Plugins.Diagnostics.ConnectionString";

    private Autoscaler autoscaler;

    public override void Run() {
      try {
        // This is a sample worker implementation. Replace with your logic.
        Trace.WriteLine("HeuristicLab.Services.Hive.Scaler entry point called", "Information");

        var hiveGlobalUsageCounter = PerformanceCounterHelper.HiveGlobalUsage;
        while (true) {
          Thread.Sleep(10000);
          Trace.WriteLine("Updating counters...", "Information");

          // Get current hive usage and update performance counter
          var usageInPercent = Convert.ToInt32(HiveHelper.GetGlobalUsage());
          hiveGlobalUsageCounter.RawValue = usageInPercent;
          Trace.WriteLine(string.Format("Hive global usage: {0}", hiveGlobalUsageCounter.RawValue));
        }
      }
      catch (Exception ex) {
        Trace.WriteLine(ex.ToString());
      }
    }

    private void InitializeConfiguration() {
      try {
        DiagnosticMonitorConfiguration config = DiagnosticMonitor.GetDefaultInitialConfiguration();
        
        // enable diagnostics logging (=> WADDiagnosticsInfrastrucutre table)
        config.DiagnosticInfrastructureLogs.ScheduledTransferLogLevelFilter = LogLevel.Verbose;
        config.DiagnosticInfrastructureLogs.ScheduledTransferPeriod = TimeSpan.FromMinutes(1d);

        // enable trace logging (=> WADLogs)
        config.Logs.ScheduledTransferLogLevelFilter = LogLevel.Verbose;
        config.Logs.ScheduledTransferPeriod = TimeSpan.FromMinutes(1d);

        // enable performance counter logging (=> WADPerformanceCounters table)
        config.PerformanceCounters.ScheduledTransferPeriod = TimeSpan.FromMinutes(1d);
        config.PerformanceCounters.BufferQuotaInMB = 128;
        config.PerformanceCounters.DataSources.Add(
           new PerformanceCounterConfiguration() {
             // Add the global usage counter of hive
             CounterSpecifier = PerformanceCounterHelper.HiveCounterGlobalUsage,
             SampleRate = TimeSpan.FromSeconds(10d)
           }
        );
        DiagnosticMonitor.Start(WADConnectionString, config);
      }
      catch (Exception ex) {
        Trace.Write(ex.ToString());
      }
    }

    public override bool OnStart() {
      // Set the maximum number of concurrent connections 
      ServicePointManager.DefaultConnectionLimit = 12;

      // Initializes all required performance counters for OaaS
      PerformanceCounterHelper.InitializePerformanceCounters();

      // Transfer performance counters to windows azure
      InitializeConfiguration();

      // Start auto scaler
      autoscaler = EnterpriseLibraryContainer.Current.GetInstance<Autoscaler>();
      autoscaler.Start();

      // For information on handling configuration changes
      // see the MSDN topic at http://go.microsoft.com/fwlink/?LinkId=166357.

      return base.OnStart();
    }
  }
}