using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using HeuristicLab.Services.Hive;
using DA = HeuristicLab.Services.Hive.DataAccess;
using DT = HeuristicLab.Services.Hive.DataTransfer;

namespace HeuristicLab.Services.Optimization.Scaler.Hive {
  public static class HiveHelper {
    public static double GetGlobalUsage() {
      // from Status.aspx.cs of HeuristicLab.Services.Hive.WebRole
      var dao = ServiceLocator.Instance.HiveDao;
      var transactionManager = ServiceLocator.Instance.TransactionManager;
      IEnumerable<DT.Slave> onlineSlaves = new List<DT.Slave>();
      IEnumerable<Guid> resourceIds = new List<Guid>();

      transactionManager.UseTransaction(() => {
        resourceIds = dao.GetResources(x => true).Select(y => y.Id);
      }, false, false);

      transactionManager.UseTransaction(() => {
        onlineSlaves = dao.GetSlaves(x => (x.SlaveState == DA.SlaveState.Calculating || x.SlaveState == DA.SlaveState.Idle) && resourceIds.Contains(x.ResourceId));
      }, false, false);

      return onlineSlaves.Count() > 0 ? onlineSlaves.Average(s => s.CpuUtilization) : 0.0d;
    }
  }
}