using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PFCRip
{
  public class PFCFile
  {
    #region Declarations

    private byte[] _data;
    private PFCHeader _header;

    #endregion

    #region Constructors / Teardown

    public PFCFile(byte[] data, bool ignoreErrors)
    {
      _data = data;

      _Parse();
    }

    #endregion

    #region Public Properties

    public PFCHeader Header
    {
      get
      {
        return _header;
      }
    }

    #endregion

    #region Public Methods

    public void ExtractFavorites(string directory, bool collapseToOneDirectory)
    {
      _DisplayEntry(directory, !collapseToOneDirectory, _header.Entries, _header.Entries[1], directory, true);
    }

    #endregion

    #region Private Methods

    private void _Parse()
    {
      if (_data == null || _data.Length == 0)
        throw new InvalidOperationException("Data cannot be empty");

      string header = LittleEndianConverter.GetString(_data, 0, 8);
      if (header != "AOLVM100")
        throw new InvalidOperationException("Invalid header: " + header);
      
      //Get the index-table pointer
      uint ptr = LittleEndianConverter.ToUInt32(_data, 0x10);
      _header = new PFCHeader(_data, ptr);
    }

    private static void _DisplayEntry(string rootPath, bool recurseDirectories, PFCEntry[] allEntries, PFCEntry entry, string subFolder, bool atRoot)
    {
      string title = LittleEndianConverter.GetSafeString(entry.EntryData);

      if (entry.IsFolder)
      {
        //Dig down into the folder
        if (entry.ChildPtr > 0)
        {
          if (atRoot)
          {
            title = System.IO.Path.GetFileName(title); //For the "root", just get the file name of the PFC
            subFolder += "\\" + Utilities.SanitizePath(title, '_');
            rootPath = subFolder;
          }
          else
          {
            if (recurseDirectories)
              subFolder += "\\" + Utilities.SanitizePath(title, '_');
            else
              subFolder = rootPath + "\\" + Utilities.SanitizePath(title, '_');
          }

          if (!System.IO.Directory.Exists(subFolder))
            System.IO.Directory.CreateDirectory(subFolder);
        }

        if (entry.ChildPtr > 0)
          _DisplayEntry(rootPath, recurseDirectories, allEntries, allEntries[entry.ChildPtr], subFolder, false);
      }
      else
      {
        //This is a legitimate entry, see what type it is
        if (entry.DataPtr > 0)
        {
          switch (entry.Type)
          {
            case 0x0002: //Favorite
              {
                var record = new PFCDataRecord(allEntries[entry.DataPtr].Data);
                var url = record.SubItems[0x05]; //actual URL data

                //Write a .lnk shortcut file for this URL
                _WriteURLFile(subFolder, title, LittleEndianConverter.GetSafeString(url.Data));

                break;
              }
            default:
              break;
          }
        }
      }

      //Then, display the next entry
      if (entry.NextPtr > 0)
        _DisplayEntry(rootPath, recurseDirectories, allEntries, allEntries[entry.NextPtr], subFolder, false);

      //We're done displaying entries in this folder, so move on up and recurse back to where we came from
      subFolder = System.IO.Directory.GetParent(subFolder).FullName;
    }

    private static void _WriteURLFile(string path, string title, string URL)
    {
      string filePath = String.Format("{0}\\{1}.url", path, Utilities.SanitizePath(title, '_'));
      var file = new System.IO.StreamWriter(filePath);
      file.WriteLine("[InternetShortcut]");
      file.WriteLine("URL=" + URL);
      file.Close();
    }

    #endregion
  }
}