Thumbnail Maker

thumbnailMaker.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;

namespace ThumbnailGenerator
{
    class Hammer
    {
        private static string SOURCE_DIRECTORY = "Source directory";
        private static string TARGET_DIRECTORY = "Target directory";
        private static string FILENAME_PATTERN = "Filename pattern";
        private static string FILENAME_FORMAT = "Filename format";
        private static string THUMBNAIL_WIDTH = "Thumbnail width";

        public static void Main(string[] args)
        {
            Dictionary<string, string> prompts = new Dictionary<string, string>()
            {
                { SOURCE_DIRECTORY, Directory.GetCurrentDirectory() },
                { TARGET_DIRECTORY, Directory.GetCurrentDirectory() },
                { FILENAME_PATTERN, @"^(.*)\.(.*)$" },
                { FILENAME_FORMAT, "{0}_thumbnail.{1}" },
                { THUMBNAIL_WIDTH, "200" }
            };

            try {

                Console.WriteLine("Welcome to Hammer!\nThis utility will help you create thumbnails from larger images.");
                List<string> keys = new List<string>(prompts.Keys);
                foreach (string key in keys) {
                    Console.Write("\n" + key + ": (" + prompts[key] + ") ");
                    string value = Console.ReadLine();
                    if (string.IsNullOrEmpty(value)) continue;
                    prompts[key] = value;
                }

                HammerDirectory(
                    prompts[SOURCE_DIRECTORY],
                    prompts[TARGET_DIRECTORY],
                    prompts[FILENAME_PATTERN],
                    prompts[FILENAME_FORMAT],
                    int.Parse(prompts[THUMBNAIL_WIDTH])
                );
            }
            catch (FormatException)
            {
                Console.WriteLine("Your file name pattern does not match your file name format (pattern: '" + prompts[FILENAME_PATTERN] + "', format: '" + prompts[FILENAME_FORMAT] + "').");
            }
            catch (Exception ex)
            {
                string innerException = ex.InnerException != null ? ex.InnerException.Message : "No inner exception";
                Console.WriteLine("Exception: " + ex.Message + " (" + innerException + ").");
            }
            Console.ReadKey(true);
        }
        
        public static void HammerDirectory(string sourceDir, string targetDir, string fileNamePattern, string fileNameFormat, int newWidth)
        {
            if (sourceDir == null || !Directory.Exists(sourceDir)) sourceDir = Directory.GetCurrentDirectory();
            if (targetDir == null || !Directory.Exists(targetDir)) targetDir = sourceDir;
            if (fileNamePattern == null) fileNamePattern = @"^(.*)\.(.*)$";
            if (fileNameFormat == null) fileNameFormat = "{0}_thumb.{1}";
            if (newWidth < 32) newWidth = 32;

            ImageAttributes imgAttrs = new ImageAttributes();
            imgAttrs.SetWrapMode(WrapMode.TileFlipXY);
            Regex fileNameRegex = new Regex(fileNamePattern);
            IEnumerable<string> files = Directory
                .GetFiles(sourceDir, "*.*", SearchOption.TopDirectoryOnly)
                .Where(path => fileNameRegex.IsMatch(path));
            
            foreach (string file in files)
            {
                string newFileName = GetNewFileName(file, targetDir, fileNameRegex, fileNameFormat);
                Bitmap thumbnail = GetThumbnail(file, newWidth, imgAttrs);
                thumbnail.Save(newFileName);
            }
        }

        private static string GetNewFileName(string originalFileName, string targetDir, Regex fileNameRegex, string fileNameFormat)
        {
            string fileName = originalFileName.Substring(originalFileName.LastIndexOf(Path.DirectorySeparatorChar) + 1);
            object[] fileNameFormatArgs = fileNameRegex.Match(fileName).Groups.Cast<Capture>().Skip(1).Select(c => c.Value).ToArray();
            return Path.Combine(targetDir, string.Format(fileNameFormat, fileNameFormatArgs));
        }

        private static Bitmap GetThumbnail(string originalFileName, int newWidth, ImageAttributes imgAttrs)
        {
            Image original = Image.FromFile(originalFileName);
            int newHeight = (int)((float)original.Height * ((float)newWidth / (float)original.Width));
            Bitmap target = new Bitmap(newWidth, newHeight);
            Graphics copier = Graphics.FromImage(target);
            copier.InterpolationMode = InterpolationMode.HighQualityBicubic;
            copier.CompositingQuality = CompositingQuality.Default;
            copier.CompositingMode = CompositingMode.SourceCopy;
            Rectangle thumbRect = new Rectangle(0, 0, newWidth, newHeight);
            copier.DrawImage(original, thumbRect, 0, 0, original.Width, original.Height, GraphicsUnit.Pixel, imgAttrs);
            return target;
        }
    }
}