using System;
using System.Collections.Generic;
using System.Text;
using BinaryTrees;

/*
     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 OpenMCDF - Compound Document Format library.

     The Initial Developer of the Original Code is Federico Blaseotto.
*/


namespace OpenMcdf
{
    /// <summary>
    /// Abstract base class for Structured Storage entities.
    /// </summary>
    /// <example>
    /// <code>
    /// 
    /// const String STORAGE_NAME = "report.xls";
    /// CompoundFile cf = new CompoundFile(STORAGE_NAME);
    ///
    /// FileStream output = new FileStream("LogEntries.txt", FileMode.Create);
    /// TextWriter tw = new StreamWriter(output);
    ///
    /// // CFItem represents both storage and stream items
    /// VisitedEntryAction va = delegate(CFItem item)
    /// {
    ///      tw.WriteLine(item.Name);
    /// };
    ///
    /// cf.RootStorage.VisitEntries(va, true);
    ///
    /// tw.Close();
    /// 
    /// </code>
    /// </example>
    public abstract class CFItem : IComparable
    {
        private CompoundFile compoundFile;

        protected CompoundFile CompoundFile
        {
            get { return compoundFile; }
        }

        protected void CheckDisposed()
        {
            if (compoundFile.IsClosed)
                throw new CFDisposedException("Owner Compound file has been closed and owned items have been invalidated");
        }

        protected CFItem()
        {
        }

        protected CFItem(CompoundFile compoundFile)
        {
            this.compoundFile = compoundFile;
        }

        #region IDirectoryEntry Members

        private IDirectoryEntry dirEntry;

        internal IDirectoryEntry DirEntry
        {
            get { return dirEntry; }
            set { dirEntry = value; }
        }



        internal int CompareTo(CFItem other)
        {
            return this.dirEntry.CompareTo(other.DirEntry);
        }



    



        #endregion

        #region IComparable Members

        public int CompareTo(object obj)
        {
            return this.dirEntry.CompareTo(((CFItem)obj).DirEntry);
        }

        #endregion

        public static bool operator ==(CFItem leftItem, CFItem rightItem)
        {
            // If both are null, or both are same instance, return true.
            if (System.Object.ReferenceEquals(leftItem, rightItem))
            {
                return true;
            }

            // If one is null, but not both, return false.
            if (((object)leftItem == null) || ((object)rightItem == null))
            {
                return false;
            }

            // Return true if the fields match:
            return leftItem.CompareTo(rightItem) == 0;
        }

        public static bool operator !=(CFItem leftItem, CFItem rightItem)
        {
            return !(leftItem == rightItem);
        }

        public override bool Equals(object obj)
        {
            return this.CompareTo(obj) == 0;
        }

        public override int GetHashCode()
        {
            return this.dirEntry.GetEntryName().GetHashCode();
        }

        /// <summary>
        /// Get entity name
        /// </summary>
        public String Name
        {
            get
            {
                String n = this.dirEntry.GetEntryName();
                if (n != null && n.Length > 0)
                {
                    return n.TrimEnd('\0');
                }
                else
                    return String.Empty;
            }
        }

        /// <summary>
        /// Size in bytes of the item. It has a valid value 
        /// only if entity is a stream, otherwise it is setted to zero.
        /// </summary>
        public long Size
        {
            get
            {
                return this.dirEntry.Size;
            }
        }


        /// <summary>
        /// Return true if item is Storage
        /// </summary>
        /// <remarks>
        /// This check doesn't use reflection or runtime type information
        /// and doesn't suffer related performance penalties.
        /// </remarks>
        public bool IsStorage
        {
            get
            {
                return this.dirEntry.StgType == StgType.StgStorage;
            }
        }

        /// <summary>
        /// Return true if item is a Stream
        /// </summary>
        /// <remarks>
        /// This check doesn't use reflection or runtime type information
        /// and doesn't suffer related performance penalties.
        /// </remarks>
        public bool IsStream
        {
            get
            {
                return this.dirEntry.StgType == StgType.StgStream;
            }
        }

        /// <summary>
        /// Return true if item is the Root Storage
        /// </summary>
        /// <remarks>
        /// This check doesn't use reflection or runtime type information
        /// and doesn't suffer related performance penalties.
        /// </remarks>
        public bool IsRoot
        {
            get
            {
                return this.dirEntry.StgType == StgType.StgRoot;
            }
        }

        /// <summary>
        /// Get/Set the Creation Date of the current item
        /// </summary>
        public DateTime CreationDate
        {
            get
            {
                return DateTime.FromFileTime(BitConverter.ToInt64(this.dirEntry.CreationDate, 0));
            }

            set
            {
                if (this.dirEntry.StgType != StgType.StgStream && this.dirEntry.StgType != StgType.StgRoot)
                    this.dirEntry.CreationDate = BitConverter.GetBytes((value.ToFileTime()));
                else
                    throw new CFException("Creation Date can only be set on storage entries");
            }
        }

        /// <summary>
        /// Get/Set the Modify Date of the current item
        /// </summary>
        public DateTime ModifyDate
        {
            get
            {
                return DateTime.FromFileTime(BitConverter.ToInt64(this.dirEntry.ModifyDate, 0));
            }

            set
            {
                if (this.dirEntry.StgType != StgType.StgStream && this.dirEntry.StgType != StgType.StgRoot)
                    this.dirEntry.ModifyDate = BitConverter.GetBytes((value.ToFileTime()));
                else
                    throw new CFException("Modify Date can only be set on storage entries");
            }
        }

        /// <summary>
        /// Get/Set Object class Guid for Root and Storage entries.
        /// </summary>
        public Guid CLSID
        {
            get
            {
                return this.dirEntry.StorageCLSID;
            }
            set
            {
                if (this.dirEntry.StgType != StgType.StgStream)
                {
                    this.dirEntry.StorageCLSID = value;
                }
                else
                    throw new CFException("Object class GUID can only be set on Root and Storage entries");
            }
        }
    }
}
