/*

  This Source Code Form is subject to the terms of the Mozilla Public

  License, v. 2.0. If a copy of the MPL was not distributed with this

  file, You can obtain one at http://mozilla.org/MPL/2.0/.

  Copyright (C) 2009-2014 Michael Möller <mmoeller@openhardwaremonitor.org>

*/

using System.Collections.Generic;

using System.Drawing;

using System.Globalization;

using System.IO;

using System.Text;

using System.Xml;

using OpenHardwareMonitor.Hardware;

namespace OpenHardwareMonitor {

  public class PersistentSettings : ISettings {

    private IDictionary<string, string> settings = 

      new Dictionary<string, string>();

    public void Load(string fileName) {

      XmlDocument doc = new XmlDocument();

      try {

        doc.Load(fileName);

      } catch {

        try {

          File.Delete(fileName);

        } catch { }

        string backupFileName = fileName + ".backup";

        try {

          doc.Load(backupFileName);

        } catch {

          try {

            File.Delete(backupFileName);

          } catch { }

          return;

        }

      }

      XmlNodeList list = doc.GetElementsByTagName("appSettings");

      foreach (XmlNode node in list) {

        XmlNode parent = node.ParentNode;

        if (parent != null && parent.Name == "configuration" && 

          parent.ParentNode is XmlDocument) {

          foreach (XmlNode child in node.ChildNodes) {

            if (child.Name == "add") {

              XmlAttributeCollection attributes = child.Attributes;

              XmlAttribute keyAttribute = attributes["key"];

              XmlAttribute valueAttribute = attributes["value"];

              if (keyAttribute != null && valueAttribute != null && 

                keyAttribute.Value != null) {

                settings.Add(keyAttribute.Value, valueAttribute.Value);

              }

            }

          }

        }

      }

    }

    public void Save(string fileName) {

      XmlDocument doc = new XmlDocument();

      doc.AppendChild(doc.CreateXmlDeclaration("1.0", "utf-8", null));

      XmlElement configuration = doc.CreateElement("configuration");

      doc.AppendChild(configuration);

      XmlElement appSettings = doc.CreateElement("appSettings");

      configuration.AppendChild(appSettings);

      foreach (KeyValuePair<string, string> keyValuePair in settings) {

        XmlElement add = doc.CreateElement("add");

        add.SetAttribute("key", keyValuePair.Key);

        add.SetAttribute("value", keyValuePair.Value);

        appSettings.AppendChild(add);

      }

      byte[] file;

      using (var memory = new MemoryStream()) {

        using (var writer = new StreamWriter(memory, Encoding.UTF8)) {

          doc.Save(writer);

        }

        file = memory.ToArray();

      }

      string backupFileName = fileName + ".backup";

      if (File.Exists(fileName)) {

        try {

          File.Delete(backupFileName);

        } catch { }

        try {

          File.Move(fileName, backupFileName);

        } catch { }

      }

      using (var stream = new FileStream(fileName, 

        FileMode.Create, FileAccess.Write))

      {

        stream.Write(file, 0, file.Length);

      }

      try {

        File.Delete(backupFileName);

      } catch { }

    }

    public bool Contains(string name) {

      return settings.ContainsKey(name);

    }

    public void SetValue(string name, string value) {

      settings[name] = value;

    }

    public string GetValue(string name, string value) {

      string result;

      if (settings.TryGetValue(name, out result))

        return result;

      else

        return value;

    }

    public void Remove(string name) {

      settings.Remove(name);

    }

    public void SetValue(string name, int value) {

      settings[name] = value.ToString();

    }

    public int GetValue(string name, int value) {

      string str;

      if (settings.TryGetValue(name, out str)) {

        int parsedValue;

        if (int.TryParse(str, out parsedValue))

          return parsedValue;

        else

          return value;

      } else {

        return value;

      }

    }

    public void SetValue(string name, float value) {

      settings[name] = value.ToString(CultureInfo.InvariantCulture);

    }

    public float GetValue(string name, float value) {

      string str;

      if (settings.TryGetValue(name, out str)) {

        float parsedValue;

        if (float.TryParse(str, NumberStyles.Float, 

          CultureInfo.InvariantCulture, out parsedValue))

          return parsedValue;

        else

          return value;

      } else {

        return value;

      }

    }

    public void SetValue(string name, bool value) {

      settings[name] = value ? "true" : "false";

    }

    public bool GetValue(string name, bool value) {

      string str;

      if (settings.TryGetValue(name, out str)) {

        return str == "true";

      } else {

        return value;

      }

    }

    public void SetValue(string name, Color color) {

      settings[name] = color.ToArgb().ToString("X8");

    }

    public Color GetValue(string name, Color value) {

      string str;

      if (settings.TryGetValue(name, out str)) {

        int parsedValue;

        if (int.TryParse(str, NumberStyles.HexNumber,

          CultureInfo.InvariantCulture, out parsedValue))

          return Color.FromArgb(parsedValue);

        else

          return value;

      } else {

        return value;

      }

    }

  }

}