#region MigraDoc - Creating Documents on the Fly
//
// Authors:
//   Stefan Lange
//   Klaus Potzesny
//   David Stephensen
//
// Copyright (c) 2001-2017 empira Software GmbH, Cologne Area (Germany)
//
// http://www.pdfsharp.com
// http://www.migradoc.com
// http://sourceforge.net/projects/pdfsharp
//
// 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 NONINFRINGEMENT. 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.
#endregion

using System;
using System.Collections.Generic;

namespace MigraDoc.DocumentObjectModel
{
    /// <summary>
    /// Deals with image file names, searches along the image path, checks if images exist etc.
    /// </summary>
    public class ImageHelper
    {
        /// <summary>
        /// Gets the first existing image from the subfolders.
        /// </summary>
        public static string GetImageName(string root, string filename, string imagePath)
        {
            List<string> subfolders = new List<string>(imagePath.Split(new [] { ';' }, StringSplitOptions.RemoveEmptyEntries));
            subfolders.Add("");

            foreach (string subfolder in subfolders)
            {
                string fullname = System.IO.Path.Combine(System.IO.Path.Combine(root, subfolder), filename);
                int pageNumber;
                string realFile = ExtractPageNumber(fullname, out pageNumber);

#if !NETFX_CORE
                if (System.IO.File.Exists(realFile))
                    return fullname;
#else
                throw new NotImplementedException();
                //if (System.IO.File.Exists(realFile))
                //    return fullname;
#endif
            }
            return null;
        }

        /// <summary>
        /// Gets a value indicating whether the filename given in the referenceFilename exists in the subfolders.
        /// </summary>
        public static bool InSubfolder(string root, string filename, string imagePath, string referenceFilename)
        {
            List<string> subfolders = new List<string>(imagePath.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries));
            subfolders.Add("");

            foreach (string subfolder in subfolders)
            {
                string fullname = System.IO.Path.Combine(System.IO.Path.Combine(root, subfolder), filename);
                int pageNumber;
                string realFile = ExtractPageNumber(fullname, out pageNumber);
#if !NETFX_CORE
                if (System.IO.File.Exists(realFile))
                {
                    if (fullname == referenceFilename)
                        return true;
                }
#else
                throw new NotImplementedException();
#endif
            }
            return false;
        }

        /// <summary>
        /// Extracts the page number if the path has the form 'MyFile.pdf#123' and returns
        /// the actual path without the number sign and the following digits.
        /// </summary>
        public static string ExtractPageNumber(string path, out int pageNumber)
        {
            // Note: duplicated from class XPdfForm
            if (path == null)
                throw new ArgumentNullException("path");

            pageNumber = 0;
            int length = path.Length;
            if (length != 0)
            {
                length--;
                if (Char.IsDigit(path, length))
                {
                    while (Char.IsDigit(path, length) && length >= 0)
                        length--;
                    if (length > 0 && path[length] == '#')
                    {
                        // must have at least one dot left of colon to distinguish from e.g. '#123'
                        if (path.IndexOf('.') != -1)
                        {
                            pageNumber = Int32.Parse(path.Substring(length + 1));
                            path = path.Substring(0, length);
                        }
                    }
                }
            }
            return path;
        }
    }
}