//
// Attachment.cs
//
// Author: Kees van Spelde <sicos2002@hotmail.com>
//
// Copyright (c) 2013-2018 Magic-Sessions. (www.magic-sessions.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using MsgReader.Exceptions;
using MsgReader.Helpers;
using MsgReader.Localization;
using OpenMcdf;

namespace MsgReader.Outlook
{
    public partial class Storage
    {        
        /// <summary>
        /// Class represents an attachment
        /// </summary>
        public sealed class Attachment : Storage
        {
            #region Fields
            /// <summary>
            /// contains the data of the attachment as an byte array
            /// </summary>
            private byte[] _data;
            #endregion

            #region Properties
            /// <summary>
            /// The name of the <see cref="CFStorage"/> that contains this attachment
            /// </summary>
            internal string StorageName { get; }

            /// <summary>
            /// Returns the filename of the attachment
            /// </summary>
            public string FileName { get; private set; }

            /// <summary>
            /// Retuns the data
            /// </summary>
            public byte[] Data => _data ?? GetMapiPropertyBytes(MapiTags.PR_ATTACH_DATA_BIN);

            /// <summary>
            /// Returns the content id or null when not available
            /// </summary>
            public string ContentId { get; }

            /// <summary>
            /// Returns the rendering position or -1 when unknown
            /// </summary>
            public int RenderingPosition { get; }

            /// <summary>
            /// True when the attachment is inline
            /// </summary>
            public bool IsInline { get; }

            /// <summary>
            /// True when the attachment is a contact photo. This can only be true
            /// when the <see cref="Storage.Message"/> object is an 
            /// <see cref="Storage.Contact"/> object.
            /// </summary>
            public bool IsContactPhoto { get; }

            /// <summary>
            /// Returns the date and time when the attachment was created or null
            /// when not available
            /// </summary>
            public DateTime? CreationTime { get; }

            /// <summary>
            /// Returns the date and time when the attachment was last modified or null
            /// when not available
            /// </summary>
            public DateTime? LastModificationTime { get; }

            /// <summary>
            /// Returns the MAPI Property Hidden, the value may only exist when it has been set True
            /// </summary>
            public bool Hidden { get; private set; }

            /// <summary>
            /// Returns <c>true</c> when the attachment is an OLE attachment
            /// </summary>
            public bool OleAttachment { get; }
            #endregion
            
            #region Constructors
            /// <summary>
            /// Creates an attachment object from a <see cref="Mime.MessagePart"/>
            /// </summary>
            /// <param name="attachment"></param>
            internal Attachment(Mime.MessagePart attachment)
            {
                ContentId = attachment.ContentId;
                IsInline = ContentId != null;
                IsContactPhoto = false;
                RenderingPosition = -1;
                _data = attachment.Body;
                FileName = FileManager.RemoveInvalidFileNameChars(attachment.FileName);
                StorageName = null;
            }

            /// <summary>
            /// Initializes a new instance of the <see cref="Storage.Attachment" /> class.
            /// </summary>
            /// <param name="message"> The message. </param>
            /// <param name="storageName">The name of the <see cref="CFStorage"/> that contains this attachment</param>
            internal Attachment(Storage message, string storageName) : base(message._rootStorage)
            {
                StorageName = storageName;

                GC.SuppressFinalize(message);
                _propHeaderSize = MapiTags.PropertiesStreamHeaderAttachOrRecip;

                CreationTime = GetMapiPropertyDateTime(MapiTags.PR_CREATION_TIME);
                LastModificationTime = GetMapiPropertyDateTime(MapiTags.PR_LAST_MODIFICATION_TIME);

                ContentId = GetMapiPropertyString(MapiTags.PR_ATTACH_CONTENTID);
                IsInline = ContentId != null;

                var isHidden = GetMapiPropertyBool(MapiTags.PR_ATTACHMENT_HIDDEN);
                if (isHidden != null)
                    Hidden = isHidden.Value;

                var isContactPhoto = GetMapiPropertyBool(MapiTags.PR_ATTACHMENT_CONTACTPHOTO);
                if (isContactPhoto == null)
                    IsContactPhoto = false;
                else
                    IsContactPhoto = (bool) isContactPhoto;

                var renderingPosition = GetMapiPropertyInt32(MapiTags.PR_RENDERING_POSITION);
                if (renderingPosition == null)
                    RenderingPosition = -1;
                else
                    RenderingPosition = (int) renderingPosition;

                var fileName = GetMapiPropertyString(MapiTags.PR_ATTACH_LONG_FILENAME);

                if (string.IsNullOrEmpty(fileName))
                    fileName = GetMapiPropertyString(MapiTags.PR_ATTACH_FILENAME);

                if (string.IsNullOrEmpty(fileName))
                    fileName = GetMapiPropertyString(MapiTags.PR_DISPLAY_NAME);

                FileName = fileName != null
                    ? FileManager.RemoveInvalidFileNameChars(fileName)
                    : LanguageConsts.NameLessFileName;

                var attachmentMethod = GetMapiPropertyInt32(MapiTags.PR_ATTACH_METHOD);

                switch (attachmentMethod)
                {
                    case MapiTags.ATTACH_BY_REFERENCE:
                    case MapiTags.ATTACH_BY_REF_RESOLVE:
                    case MapiTags.ATTACH_BY_REF_ONLY:
                        ResolveAttachment();
                        break;

                    case MapiTags.ATTACH_OLE:
                        var storage = GetMapiProperty(MapiTags.PR_ATTACH_DATA_BIN) as CFStorage;
                        var attachmentOle = new Attachment(new Storage(storage), null);
                        _data = attachmentOle.GetStreamBytes("CONTENTS");
                        if (_data != null)
                        {
                            var fileTypeInfo = FileTypeSelector.GetFileTypeFileInfo(Data);

                            if (string.IsNullOrEmpty(FileName))
                                FileName = fileTypeInfo.Description;

                            FileName += "." + fileTypeInfo.Extension.ToLower();
                        }
                        else
                            // http://www.devsuperpage.com/search/Articles.aspx?G=10&ArtID=142729
                            _data = attachmentOle.GetStreamBytes("\u0002OlePres000");

                        if (_data != null)
                        {
                            try
                            {
                                SaveImageAsPng(40);
                            }
                            catch (ArgumentException)
                            {
                                SaveImageAsPng(0);
                            }
                        }
                        else
                            throw new MRUnknownAttachmentFormat("Can not read the attachment");

                        OleAttachment = true;
                        IsInline = true;
                        break;
                }
            }
            #endregion

            #region ResolveAttachment
            /// <summary>
            /// Tries to resolve an attachment when the <see cref="MapiTags.PR_ATTACH_METHOD"/> is of the type
            /// <see cref="MapiTags.ATTACH_BY_REFERENCE"/>, <see cref="MapiTags.ATTACH_BY_REF_RESOLVE"/> or
            /// <see cref="MapiTags.ATTACH_BY_REF_ONLY"/>
            /// </summary>
            private void ResolveAttachment()
            {
                //The PR_ATTACH_PATHNAME or PR_ATTACH_LONG_PATHNAME property contains a fully qualified path identifying the attachment
                var attachPathName = GetMapiPropertyString(MapiTags.PR_ATTACH_PATHNAME);
                var attachLongPathName = GetMapiPropertyString(MapiTags.PR_ATTACH_LONG_PATHNAME);

                // Because we are not sure we can access the files we put everything in a try catch
                try
                {
                    if (attachLongPathName != null)
                    {
                        _data = File.ReadAllBytes(attachLongPathName);
                        return;
                    }

                    if (attachPathName == null) return;
                    _data = File.ReadAllBytes(attachPathName);
                }
                // ReSharper disable once EmptyGeneralCatchClause
                catch {}
            }
            #endregion

            #region SaveImageAsPng
            /// <summary>
            /// Tries to save an attachment as a png file with the user specified buffer
            /// </summary>
            private void SaveImageAsPng(int bufferOffset)
            {
                if (bufferOffset > _data.Length)
                    throw new ArgumentOutOfRangeException(nameof(bufferOffset), bufferOffset,
                        @"Buffer Offset value cannot be greater than the length of the image byte array!");

                var length = _data.Length - bufferOffset;
                var bytes = new byte[length];
                Buffer.BlockCopy(_data, bufferOffset, bytes, 0, length);
                using (var inputStream = new MemoryStream(bytes))
                using (var image = Image.FromStream(inputStream))
                using (var outputStream = new MemoryStream())
                {
                    image.Save(outputStream, ImageFormat.Png);
                    outputStream.Position = 0;
                    _data = outputStream.ToByteArray();
                    FileName = "ole0.bmp";
                }
            }
            #endregion
        }
    }
}