using System;
using System.IO;
using System.Xml;

namespace Server.Engines.Reports
{
  public abstract class PersistanceWriter
  {
    public abstract void SetInt32(string key, int value);
    public abstract void SetBoolean(string key, bool value);
    public abstract void SetString(string key, string value);
    public abstract void SetDateTime(string key, DateTime value);

    public abstract void BeginObject(PersistableType typeID);
    public abstract void BeginChildren();
    public abstract void FinishChildren();
    public abstract void FinishObject();

    public abstract void WriteDocument(PersistableObject root);
    public abstract void Close();
  }

  public sealed class XmlPersistanceWriter : PersistanceWriter
  {
    private string m_RealFilePath;
    private string m_TempFilePath;
    private string m_Title;

    private StreamWriter m_Writer;
    private XmlTextWriter m_Xml;

    public XmlPersistanceWriter(string filePath, string title)
    {
      m_RealFilePath = filePath;
      m_TempFilePath = Path.ChangeExtension(filePath, ".tmp");

      m_Writer = new StreamWriter(m_TempFilePath);
      m_Xml = new XmlTextWriter(m_Writer);

      m_Title = title;
    }

    public override void SetInt32(string key, int value)
    {
      m_Xml.WriteAttributeString(key, XmlConvert.ToString(value));
    }

    public override void SetBoolean(string key, bool value)
    {
      m_Xml.WriteAttributeString(key, XmlConvert.ToString(value));
    }

    public override void SetString(string key, string value)
    {
      if (value != null)
        m_Xml.WriteAttributeString(key, value);
    }

    public override void SetDateTime(string key, DateTime value)
    {
      if (value != DateTime.MinValue)
        m_Xml.WriteAttributeString(key, XmlConvert.ToString(value, XmlDateTimeSerializationMode.Utc));
    }

    public override void BeginObject(PersistableType typeID)
    {
      m_Xml.WriteStartElement(typeID.Name);
    }

    public override void BeginChildren()
    {
    }

    public override void FinishChildren()
    {
    }

    public override void FinishObject()
    {
      m_Xml.WriteEndElement();
    }

    public override void WriteDocument(PersistableObject root)
    {
      Console.WriteLine("Reports: {0}: Save started", m_Title);

      m_Xml.Formatting = Formatting.Indented;
      m_Xml.IndentChar = '\t';
      m_Xml.Indentation = 1;

      m_Xml.WriteStartDocument(true);

      root.Serialize(this);

      Console.WriteLine("Reports: {0}: Save complete", m_Title);
    }

    public override void Close()
    {
      m_Xml.Close();
      m_Writer.Close();

      try
      {
        string renamed = null;

        if (File.Exists(m_RealFilePath))
        {
          renamed = Path.ChangeExtension(m_RealFilePath, ".rem");
          File.Move(m_RealFilePath, renamed);
          File.Move(m_TempFilePath, m_RealFilePath);
          File.Delete(renamed);
        }
        else
        {
          File.Move(m_TempFilePath, m_RealFilePath);
        }
      }
      catch (Exception ex)
      {
        Console.WriteLine(ex);
      }
    }
  }
}