using System;

using System.Collections.Generic;

using System.Management.Instrumentation;

using OpenHardwareMonitor.Hardware;

[assembly: Instrumented("root/OpenHardwareMonitor")]

[System.ComponentModel.RunInstaller(true)]

public class InstanceInstaller : DefaultManagementProjectInstaller { }

namespace OpenHardwareMonitor.WMIProvider {

  public class WmiProvider : IDisposable {

    private List<IWmiClass> _activeInstances;

    public WmiProvider(IComputer computer) {

      _activeInstances = new List<IWmiClass>();

      foreach (IHardware hardware in computer.Hardware)

        ComputerHardwareAdded(hardware);

      computer.HardwareAdded += ComputerHardwareAdded;

      computer.HardwareRemoved += ComputerHardwareRemoved;

    }

    public void Update() {

      foreach (IWmiClass instance in _activeInstances)

        instance.Update();

    }

    #region Eventhandlers

    private void ComputerHardwareAdded(IHardware hardware) {

      if (!Exists(hardware.Identifier.ToString())) {

        foreach (ISensor sensor in hardware.Sensors)

          HardwareSensorAdded(sensor);

        hardware.SensorAdded += HardwareSensorAdded;

        hardware.SensorRemoved += HardwareSensorRemoved;

        Hardware hw = new Hardware(hardware);

        _activeInstances.Add(hw);

        Instrumentation.Publish(hw);

      }

      foreach (IHardware subHardware in hardware.SubHardware)

        ComputerHardwareAdded(subHardware);

    }

    private void HardwareSensorAdded(ISensor data) {

      Sensor sensor = new Sensor(data);

      _activeInstances.Add(sensor);

      Instrumentation.Publish(sensor);

    }

    private void ComputerHardwareRemoved(IHardware hardware) {

      hardware.SensorAdded -= HardwareSensorAdded;

      hardware.SensorRemoved -= HardwareSensorRemoved;

      foreach (ISensor sensor in hardware.Sensors) 

        HardwareSensorRemoved(sensor);

      foreach (IHardware subHardware in hardware.SubHardware)

        ComputerHardwareRemoved(subHardware);

      RevokeInstance(hardware.Identifier.ToString());

    }

    private void HardwareSensorRemoved(ISensor sensor) {

      RevokeInstance(sensor.Identifier.ToString());

    }

    #endregion

    #region Helpers

    private bool Exists(string identifier) {

      return _activeInstances.Exists(h => h.Identifier == identifier);

    }

    private void RevokeInstance(string identifier) {

      int instanceIndex = _activeInstances.FindIndex(

        item => item.Identifier == identifier.ToString()

      );

      Instrumentation.Revoke(_activeInstances[instanceIndex]);

      _activeInstances.RemoveAt(instanceIndex);

    }

    #endregion

    public void Dispose() {

      foreach (IWmiClass instance in _activeInstances)

        Instrumentation.Revoke(instance);

      _activeInstances = null;

    }

  }

}