/*
  
  Version: MPL 1.1/GPL 2.0/LGPL 2.1

  The contents of this file are subject to the Mozilla Public License Version
  1.1 (the "License"); you may not use this file except in compliance with
  the License. You may obtain a copy of the License at
 
  http://www.mozilla.org/MPL/

  Software distributed under the License is distributed on an "AS IS" basis,
  WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  for the specific language governing rights and limitations under the License.

  The Original Code is the Open Hardware Monitor code.

  The Initial Developer of the Original Code is 
  Michael Möller <m.moeller@gmx.ch>.
  Portions created by the Initial Developer are Copyright (C) 2009-2012
  the Initial Developer. All Rights Reserved.

  Contributor(s): 
    Paul Werelds
    Roland Reinl <roland-reinl@gmx.de>

  Alternatively, the contents of this file may be used under the terms of
  either the GNU General Public License Version 2 or later (the "GPL"), or
  the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  in which case the provisions of the GPL or the LGPL are applicable instead
  of those above. If you wish to allow use of your version of this file only
  under the terms of either the GPL or the LGPL, and not to allow others to
  use your version of this file under the terms of the MPL, indicate your
  decision by deleting the provisions above and replace them with the notice
  and other provisions required by the GPL or the LGPL. If you do not delete
  the provisions above, a recipient may use your version of this file under
  the terms of any one of the MPL, the GPL or the LGPL.
 
*/

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using OpenHardwareMonitor.Collections;

namespace OpenHardwareMonitor.Hardware.HDD {
  internal abstract class AbstractHarddrive : Hardware {

    private const int UPDATE_DIVIDER = 30; // update only every 30s

    // array of all harddrive types, matching type is searched in this order
    private static Type[] hddTypes = {       
      typeof(SSDPlextor),
      typeof(SSDIntel),
      typeof(SSDSandforce),
      typeof(SSDIndilinx),
      typeof(SSDSamsung),
      typeof(GenericHarddisk)
    };

    private string firmwareRevision;
    private readonly ISmart smart;

    private readonly IntPtr handle;
    private readonly int index;
    private int count;

    private IList<SmartAttribute> smartAttributes;
    private IDictionary<SmartAttribute, Sensor> sensors;

    protected AbstractHarddrive(ISmart smart, string name, 
      string firmwareRevision, int index, 
      IEnumerable<SmartAttribute> smartAttributes, ISettings settings) 
      : base(name, new Identifier("hdd",
        index.ToString(CultureInfo.InvariantCulture)), settings)
    {
      this.firmwareRevision = firmwareRevision;
      this.smart = smart;
      handle = smart.OpenDrive(index);

      smart.EnableSmart(handle, index);

      this.index = index;
      this.count = 0;

      this.smartAttributes = new List<SmartAttribute>(smartAttributes);

      CreateSensors();
    }

    public static AbstractHarddrive CreateInstance(ISmart smart, 
      int driveIndex, ISettings settings) 
    {
      IntPtr deviceHandle = smart.OpenDrive(driveIndex);

      if (deviceHandle == smart.InvalidHandle) 
        return null;

      string name;
      string firmwareRevision;
      bool nameValid = smart.ReadNameAndFirmwareRevision(deviceHandle, 
        driveIndex, out name, out firmwareRevision);
      bool smartEnabled = smart.EnableSmart(deviceHandle, driveIndex);

      DriveAttributeValue[] values = {};
      if (smartEnabled)
        values = smart.ReadSmartData(deviceHandle, driveIndex);

      smart.CloseHandle(deviceHandle);

      if (!nameValid || string.IsNullOrEmpty(name)) 
        return null;

      foreach (Type type in hddTypes) {
        // get the array of name prefixes for the current type
        NamePrefixAttribute[] namePrefixes = type.GetCustomAttributes(
          typeof(NamePrefixAttribute), true) as NamePrefixAttribute[];

        // get the array of the required SMART attributes for the current type
        RequireSmartAttribute[] requiredAttributes = type.GetCustomAttributes(
          typeof(RequireSmartAttribute), true) as RequireSmartAttribute[];

        // check if all required attributes are present
        bool allRequiredAttributesFound = true;
        foreach (var requireAttribute in requiredAttributes) {
          bool adttributeFound = false;
          foreach (DriveAttributeValue value in values) {
            if (value.Identifier == requireAttribute.AttributeId) {
              adttributeFound = true;
              break;
            }
          }
          if (!adttributeFound) {
            allRequiredAttributesFound = false;
            break;
          }
        }

        // if an attribute is missing, then try the next type
        if (!allRequiredAttributesFound)
          continue;        

        // check if there is a matching name prefix for this type
        foreach (NamePrefixAttribute prefix in namePrefixes) {
          if (name.StartsWith(prefix.Prefix, StringComparison.InvariantCulture)) 
            return Activator.CreateInstance(type, smart, name, firmwareRevision,
              driveIndex, settings) as AbstractHarddrive;
        }
      }

      // no matching type has been found
      return null;
    }

    private void CreateSensors() {
      sensors = new Dictionary<SmartAttribute, Sensor>();

      IList<Pair<SensorType, int>> sensorTypeAndChannels = 
        new List<Pair<SensorType, int>>();

      DriveAttributeValue[] values = smart.ReadSmartData(handle, index);

      foreach (SmartAttribute attribute in smartAttributes) {
        if (!attribute.SensorType.HasValue) 
          continue;

        bool found = false;
        foreach (DriveAttributeValue value in values) {
          if (value.Identifier == attribute.Identifier) {
            found = true;
            break;
          }
        }
        if (!found)
          continue;

        Pair<SensorType, int> pair = new Pair<SensorType, int>(
          attribute.SensorType.Value, attribute.SensorChannel);

        if (!sensorTypeAndChannels.Contains(pair)) {
          Sensor sensor = new Sensor(attribute.Name, 
            attribute.SensorChannel, attribute.SensorType.Value, this, 
            settings);

          sensors.Add(attribute, sensor);
          ActivateSensor(sensor);
          sensorTypeAndChannels.Add(pair);
        }     
      }
    }

    public override HardwareType HardwareType {
      get { return HardwareType.HDD; }
    }

    public virtual void UpdateAdditionalSensors(DriveAttributeValue[] values) {}

    public override void Update() {
      if (count == 0) {
        DriveAttributeValue[] values = smart.ReadSmartData(handle, index);

        foreach (KeyValuePair<SmartAttribute, Sensor> keyValuePair in sensors) {
          SmartAttribute attribute = keyValuePair.Key;          
          foreach (DriveAttributeValue value in values) {
            if (value.Identifier == attribute.Identifier) {
              Sensor sensor = keyValuePair.Value;
              sensor.Value = attribute.ConvertValue(value);
            }
          }
        }

        UpdateAdditionalSensors(values);
      }

      count++; 
      count %= UPDATE_DIVIDER; 
    }

    public override string GetReport() {
      StringBuilder r = new StringBuilder();
      DriveAttributeValue[] values = smart.ReadSmartData(handle, index);
      DriveThresholdValue[] thresholds = 
        smart.ReadSmartThresholds(handle, index);

      if (values.Length > 0) {
        r.AppendLine(this.GetType().Name);
        r.AppendLine();
        r.AppendLine("Drive name: " + name);
        r.AppendLine("Firmware version: " + firmwareRevision);
        r.AppendLine();
        r.AppendFormat(CultureInfo.InvariantCulture, 
          " {0}{1}{2}{3}{4}{5}{6}{7}",
          ("ID").PadRight(3),
          ("Description").PadRight(35),
          ("Raw Value").PadRight(13),
          ("Worst").PadRight(6),
          ("Value").PadRight(6),
          ("Thres").PadRight(6),
          ("Physical").PadRight(8),
          Environment.NewLine);

        foreach (DriveAttributeValue value in values) {
          if (value.Identifier == 0x00) 
            break;

          byte? threshold = null;
          foreach (DriveThresholdValue t in thresholds) {
            if (t.Identifier == value.Identifier) {
              threshold = t.Threshold;
            }
          }

          string description = "Unknown";
          float? physical = null;
          foreach (SmartAttribute a in smartAttributes) {
            if (a.Identifier == value.Identifier) {
              description = a.Name;
              if (a.HasRawValueConversion | a.SensorType.HasValue)
                physical = a.ConvertValue(value);
              else
                physical = null;
            }
          }

          string raw = BitConverter.ToString(value.RawValue);
          r.AppendFormat(CultureInfo.InvariantCulture, 
            " {0}{1}{2}{3}{4}{5}{6}{7}",
            value.Identifier.ToString("X2").PadRight(3),
            description.PadRight(35),
            raw.Replace("-", "").PadRight(13),
            value.WorstValue.ToString(CultureInfo.InvariantCulture).PadRight(6),
            value.AttrValue.ToString(CultureInfo.InvariantCulture).PadRight(6),
            (threshold.HasValue ? threshold.Value.ToString(
              CultureInfo.InvariantCulture) : "-").PadRight(6),
            (physical.HasValue ? physical.Value.ToString(
              CultureInfo.InvariantCulture) : "-").PadRight(8),
            Environment.NewLine);
        }
        r.AppendLine();
      }

      return r.ToString();
    }

    protected static float RawToInt(byte[] raw, byte value) {
      return (raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0];
    }

    public override void Close() {
      smart.CloseHandle(handle);
      base.Close();
    }

    public override void Traverse(IVisitor visitor) {
      foreach (ISensor sensor in Sensors)
        sensor.Accept(visitor);
    }
  }
}