//=================================================================================================
//=================================================================================================
//
// Copyright (c) 2012 Dennis Mnuskin
//
// This file is part of Droppy application.
//
// This source code is distributed under the MIT license.  For full text, see
// http://www.opensource.org/licenses/mit-license.php Same text is found in LICENSE file which
// is located in root directory of the project.
//
//=================================================================================================
//=================================================================================================

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows;
using System.Windows.Interop;

namespace Droppy
{
    /// <summary>
    /// Part of IFileOperation, indicates which file operation to perform. See MSDN's
    /// documentation of SHFILEOPSTRUCT structure for detailed explanation of these flag values.
    /// </summary>
    enum FILEOP_CODES : uint
    {
        /// <summary>
        /// Move files specified in 'From' field of IFileOperation to 'To'
        /// </summary>
        FO_MOVE     = 0x0001,

        /// <summary>
        /// Copies files specified in 'From' field of IFileOperation to 'To'
        /// </summary>
        FO_COPY     = 0x0002,

        /// <summary>
        /// Deletes files specified in 'From' field of IFileOperation
        /// </summary>
        FO_DELETE   = 0x0003,

        /// <summary>
        /// Renames the file specified in 'From' field of IFileOperation. This flag cannot be used
        /// to rename multiple files in a single IFileOperation call. Use FO_MOVE instead.
        /// </summary>
        FO_RENAME   = 0x0004,
    }


    /// <summary>
    /// Flags that control the behavior of IFileOperation object. See MSDN's documentation of
    /// SHFILEOPSTRUCT structure for detailed explanation of these flag values.
    /// </summary>
    [Flags]
    enum FILEOP_FLAGS
    {
        FOF_MULTIDESTFILES          = 0x00000001,
        FOF_CONFIRMMOUSE            = 0x00000002,
        FOF_SILENT                  = 0x00000004,
        FOF_RENAMEONCOLLISION       = 0x00000008,
        FOF_NOCONFIRMATION          = 0x00000010,
        FOF_WANTMAPPINGHANDLE       = 0x00000020,
        FOF_ALLOWUNDO               = 0x00000040,
        FOF_FILESONLY               = 0x00000080,
        FOF_SIMPLEPROGRESS          = 0x00000100,
        FOF_NOCONFIRMMKDIR          = 0x00000200,
        FOF_NOERRORUI               = 0x00000400,
        FOF_NOCOPYSECURITYATTRIBS   = 0x00000800,
        FOF_NORECURSION             = 0x00001000, /* don't do recursion into directories */
        FOF_NO_CONNECTED_ELEMENTS   = 0x00002000, /* don't do connected files */
        FOF_WANTNUKEWARNING         = 0x00004000, /* during delete operation, warn if delete instead
                                               of recycling (even if FOF_NOCONFIRMATION) */
        FOF_NORECURSEREPARSE        = 0x00008000,

        // Flags below are available when using 2nd gne of 
        // file operation (IFileOperation COM-based)
        FOFX_NOSKIPJUNCTIONS        = 0x00010000,
        FOFX_PREFERHARDLINK         = 0x00020000,
        FOFX_SHOWELEVATIONPROMPT    = 0x00040000,
        FOFX_EARLYFAILURE           = 0x00100000,
        FOFX_PRESERVEFILEEXTENSIONS = 0x00200000,
        FOFX_KEEPNEWERFILE          = 0x00400000,
        FOFX_NOCOPYHOOKS            = 0x00800000,
        FOFX_NOMINIMIZEBOX          = 0x01000000,
        FOFX_MOVEACLSACROSSVOLUMES  = 0x02000000,
        FOFX_DONTDISPLAYSOURCEPATH  = 0x04000000,
        FOFX_DONTDISPLAYDESTPATH    = 0x08000000,

    }


    /// <summary>
    /// Implemented by an object which supports Windows shell file operation.
    /// </summary>
    interface IFileOperation
    {
        /// <summary>
        /// Ges/sets parent window for the file operation dialog if one is to be displayed
        /// </summary>
        Window ParentWindow { get; set; }

        /// <summary>
        /// Gets/sets a flag which indicates which operation to perform
        /// </summary>
        FILEOP_CODES Operation { get; set; }

        /// <summary>
        /// Gets/sets flags which control the behavior of the file operation
        /// </summary>
        FILEOP_FLAGS Flags { get; set; }

        /// <summary>
        /// Gets/sets a list of files to move, copy or delete. Wildcard characters are allowed
        /// in the file portion of each path.
        /// </summary>
        string[] From { get; set; }

        /// <summary>
        /// Gets/sets a list of destination directories.  Multiple directories can be specified
        /// if FOF_MULTIDESTFILES flag is passed in.
        /// </summary>
        string[] To { get; set; }

        /// <summary>
        /// After file operation completes, this member is set to true if a file operation was
        /// aborted by the user.
        /// </summary>
        bool AnyOpAborted { get; }

        /// <summary>
        /// This property is not currently supported. DO NOT USE IT.
        /// </summary>
        Dictionary< string, string >[] NameMappings { get; }

        /// <summary>
        /// Gets/sets a title of a progress dialog box. This property is only used if
        /// FOF_SIMPLEPROGRESS flag is specified
        /// </summary>
        string ProgressTitle { get; set; }

        /// <summary>
        /// Called to invoke file operation after other properties of this interface have been
        /// filled in.
        /// </summary>
        void Execute();
    }


    /// <summary>
    /// Implements Windows Shell file operation using first generation of file operation method.
    /// For more information about capabilities and use of this class, see MSDN Library's
    /// documentation of SHFileOperation functions.
    /// </summary>
    class FileOperationG1 : IFileOperation
    {
        #region ----------------------- Public Members ------------------------

        /// <summary>
        /// Default constructor
        /// </summary>
        public FileOperationG1()
        {
            _isAnyOpAborted = false;
        }

        #region - - - - - - - IFileOperation Interface  - - - - - - - - - - - -

        public Window ParentWindow { get; set; }
        public FILEOP_CODES Operation { get; set; }
        public FILEOP_FLAGS Flags { get; set; }
        public string[] From { get; set; }
        public string[] To { get; set; }
        public bool AnyOpAborted { get { return _isAnyOpAborted; } }
        public Dictionary< string, string >[] NameMappings { get { return null; } }
        public string ProgressTitle { get; set; }

        public void Execute()
        {
            WindowInteropHelper wih = new WindowInteropHelper( ParentWindow );
            SHFILEOPSTRUCT      fileOp = new SHFILEOPSTRUCT();
            
            if( this.Flags.HasFlag( FILEOP_FLAGS.FOF_WANTMAPPINGHANDLE ) )
            {
                throw new NotImplementedException();
            }

            fileOp.hwnd = wih.Handle;
            fileOp.wFunc = Convert.ToInt32( this.Operation );
            fileOp.pFrom = ArrayToMultiString( this.From );
            fileOp.pTo = ArrayToMultiString( this.To );
            fileOp.fAnyOperationAborted = 0;
            fileOp.fFlags = Convert.ToInt16( this.Flags );
            fileOp.hNameMapping = IntPtr.Zero;
            fileOp.lpszProgressTitle = this.ProgressTitle;

            int res = SHFileOperation( ref fileOp );
        }

        #endregion
        #endregion

        #region ----------------------- Private Members -----------------------

        private string ArrayToMultiString( string[] strings )
        {
            StringBuilder sb = new StringBuilder();

            foreach( var s in strings )
            {
                sb.Append( s ).Append( '\0' );
            }

            return sb.ToString();
        }

        #region - - - - - - - Shell API Interop - - - - - - - - - - - - - - - -

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
        private struct SHFILEOPSTRUCT
        {
            public IntPtr           hwnd;
            public Int32            wFunc;

            [MarshalAs(UnmanagedType.LPWStr)]
            public String           pFrom;

            [MarshalAs(UnmanagedType.LPWStr)]
            public String           pTo;

            public Int16            fFlags;             // zero or more FILEOP_FLAGS values (lower 16-bit only)
            public Int32            fAnyOperationAborted;
            public IntPtr           hNameMapping;

            [MarshalAs(UnmanagedType.LPWStr)]
            public String           lpszProgressTitle;
        }

        [DllImport("Shell32.dll", CharSet = CharSet.Unicode)]
        private static extern Int32 SHFileOperation( ref SHFILEOPSTRUCT lpFileOp );

        #endregion

        private bool    _isAnyOpAborted;

        #endregion
    }
}