using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using System.Globalization;
using System.Threading;

namespace Image_Sorter
{
    class Program
    {
        static readonly List<string> DNGTypes = new List<string> {"raw", "cr2", "dng"};
        static readonly List<string> ImagePrefixes = new List<string> { "", "Screenshot_", "VID"};
        static void Main(string[] args)
        {
            Console.WriteLine("Image Sorter {0} (C)2019 Brychan Dempsey");
            Console.WriteLine("Moves images from the source folder and arranges them by date (from metadata) in the destination folder");
            string SourceDir = "";
            string DestinationDir = "";
            bool copyFiles = false;
            if (args.Length > 0  && args[0].ToLower() == "\\s")
            {
                int sourceDirSpecified = Array.IndexOf(args, "\\d");
                if (sourceDirSpecified != -1)
                {
                    if (Directory.Exists(args[sourceDirSpecified + 1]))
                    {
                        SourceDir = args[sourceDirSpecified + 1];
                    }
                }
                int targetDirSpecified = Array.IndexOf(args, "\\t");
                if (targetDirSpecified != -1)
                {
                    if (Directory.Exists(args[targetDirSpecified + 1]))
                    {
                        DestinationDir = args[targetDirSpecified + 1];
                    }
                }
                else
                {
                    DestinationDir = SourceDir;
                }

                if (args.Contains("\\c"))
                {
                    copyFiles = true;
                }
                // Redirect all console writes
                Console.SetOut(new StringWriter());
            }
            else if (args.Length > 0 && (args[0] == "\\?" || args[0].ToLower() == "\\h"))
            {
                Console.WriteLine("Image Sorter");
                Console.WriteLine("Can be run in silent mode using the argument: \\s");
                Console.WriteLine("Additional flags: \\d - Source Directory (Usage: \\s \\d <soruce directory>");
                Console.WriteLine("\t\t\\t - Target Directory (Usage: \\s \\t <target directory>");
                Console.WriteLine("\t\t\\c - Copy files if this flag is specified");
                Console.WriteLine("Usage Example:");
                Console.WriteLine("\\s \\d \"C:\\Camera Files\\Images\" \\t \"C:\\Camera Files\\Sorted\\\"");
                Console.WriteLine("\nIf the destination directory is not specified, it will default to the source directory");
                Console.ReadLine();
                Environment.Exit(0);
            }
            else
            {
                
                Console.WriteLine("Enter the source directory:");
                SourceDir = Console.ReadLine();
                Console.WriteLine("Enter the destionation directory:");
                DestinationDir = Console.ReadLine();
                Console.WriteLine("Enter \'y\' to perform a copy instead of move");
                string tRead = Console.ReadLine();
                
                if (tRead.Trim().ToLower().Equals("y"))
                {
                    copyFiles = true;
                }
                
            }
            Console.WriteLine("Scanning the source directory...");
            List<string> SourceFiles = GetFiles(SourceDir);
            Console.WriteLine("Found {0} files", SourceFiles.Count());

            int processedCount = 0;
            object countLock = new object();
            Task updateFilesTask = new Task(() =>
            {
                Parallel.ForEach(SourceFiles, (filepath) =>
                {
                    string fileDestination = "";
                    DateTime photoDate = new DateTime();
                    bool hasMetadata = true;
                    using (FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.Read))
                    {
                        bool ruleMatch = false;
                        Dictionary<string, string> imgMetadata = GetMetaData(fs);
                        if (imgMetadata.ContainsKey("date"))
                        {
                            photoDate = DateTime.Parse(imgMetadata["date"]);
                            ruleMatch = true;
                        }
                        // If the file is a negative, it may have a conjugate image file
                        else if (DNGTypes.Contains(Path.GetExtension(filepath).TrimStart('.')))
                        {
                            List<string> matches = SourceFiles.FindAll((x) => Path.GetFileNameWithoutExtension(x).Equals(Path.GetFileNameWithoutExtension(filepath)) && !Path.GetExtension(x).Equals(Path.GetExtension(filepath)));
                            if (matches.Count == 1)
                            {
                                using (FileStream tfs = new FileStream(matches[0], FileMode.Open, FileAccess.Read, FileShare.Read))
                                {
                                    imgMetadata = GetMetaData(tfs);
                                }
                                if (imgMetadata.ContainsKey("date"))
                                {
                                    photoDate = DateTime.Parse(imgMetadata["date"]);
                                    Console.WriteLine(" Conjugate file found - " + Path.GetFileName(filepath));
                                    ruleMatch = true;
                                }
                            }
                        }
                        // Try parsing a date by the rules set in ImagePrefixes, using the first if found
                        else if (ImagePrefixes.Exists((x) => TryParseDate(Path.GetFileNameWithoutExtension(filepath).TrimStart(x.ToCharArray()), out photoDate)))
                        {
                            Console.WriteLine(" Date successfully parsed from file: {0} - Parsed Date: {1} ", Path.GetFileName(filepath), photoDate.ToString("dd-MM-yyyy"));
                            ruleMatch = true;
                        }
                        // Failsafe to avoid implausable dates (Greater than system year + 10, < 1990)
                        if (ruleMatch && (photoDate.Year > DateTime.Now.Year + 10 || photoDate.Year < 1990))
                        {
                            ruleMatch = false;
                        }
                        // Finally, resort to the least of the file creation time && file modified time
                        if (!ruleMatch)
                        {
                            FileSystemInfo fileInfo = new FileInfo(filepath);
                            photoDate = fileInfo.CreationTime < fileInfo.LastWriteTime ? fileInfo.CreationTime : fileInfo.LastWriteTime;
                        }
                    }
                    fileDestination = "\\" + photoDate.Year;
                    fileDestination += "\\" + CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(photoDate.Month);
                    Directory.CreateDirectory(DestinationDir + fileDestination + "\\");
                    fileDestination += "\\" + filepath.Remove(0, filepath.LastIndexOf("\\"));
                    if (copyFiles)
                    {
                        try
                        {
                            File.Copy(filepath, DestinationDir + fileDestination);
                            filepath = DestinationDir + fileDestination;
                        }
                        catch
                        {
                            Console.WriteLine("Failed to copy {0}", Path.GetFileName(filepath));
                        }

                    }
                    else
                    {
                        try
                        {
                            File.Move(filepath, DestinationDir + fileDestination);
                            filepath = DestinationDir + fileDestination;
                        }
                        catch
                        {
                            Console.WriteLine("Failed to move {0}", Path.GetFileName(filepath));
                        }

                    }
                    lock (countLock)
                    {
                        processedCount++;
                    }
                });
            });
            int lastProcessed = 0;
            updateFilesTask.Start();
            bool eval = false;
            while (!eval)
            {
                lock (countLock)
                {
                    if (processedCount != lastProcessed)
                    {
                        Console.WriteLine("{0}/{1} processed.", processedCount, SourceFiles.Count);
                        lastProcessed = processedCount;
                    }
                    if (processedCount == SourceFiles.Count)
                        eval = true;
                }
                Thread.Sleep(10);
            }
            Console.ReadLine();

        }

        static Dictionary<string,string> GetMetaData(FileStream fileStream)
        {
            
            Dictionary<string, string> Metadata = new Dictionary<string, string>();
            try
            {
                BitmapSource srcimg = BitmapFrame.Create(fileStream);
                BitmapMetadata md = (BitmapMetadata)srcimg.Metadata;
                string date = md.DateTaken;
                if (!string.IsNullOrEmpty(date))
                {
                    Metadata.Add("date", date);
                }
            }
            catch
            {
                Console.WriteLine("Couldn't get metadata - {0}", fileStream.Name);
            }
            return Metadata;
        }

        static List<string> GetFiles(string SourceDirectory)
        {
            List<string> foundFiles = Directory.GetFiles(SourceDirectory, "*", SearchOption.TopDirectoryOnly).ToList();
            foreach (var subDirectory in Directory.GetDirectories(SourceDirectory))
            {
                foundFiles.AddRange(GetFiles(subDirectory));
            }
            return foundFiles;
        }

        static bool TryParseDate(string input, out DateTime dt)
        {
            // Attempt a base conversion first

            // As datetime's built-in converter does not seem to be able to handle more complex strings,
            // convert the to a usable format before attempting to convert a datetime
            //int pos = ImagePrefixes.FindIndex(0, (x) => input.StartsWith(x));
            //input = input.Replace(ImagePrefixes[pos], ""); // Remove the prefix
            if (DateTime.TryParse(input, out dt))
                return true;
            StringBuilder converted = new StringBuilder();
            string modified = input;
            DateTime result = new DateTime();
            // if we are in the format "ddddsddsdd" we can try to parse that date
            if (isMatch(input))
            {
                int year = Convert.ToInt32(input.Substring(0, 4));
                int month = Convert.ToInt32(input.Substring(5, 2));
                int day = Convert.ToInt32(input.Substring(8, 2));
                try
                {
                    result = new DateTime(year, month, day);
                }
                catch
                {
                    return false;
                }
            }
            // Else try the straight digit parsing, so ensure we have 8 contiguous digits to parse.
            else if (isMatch(input, "dddddddd"))
            {
                int year = Convert.ToInt32(input.Substring(0, 4));
                int month = Convert.ToInt32(input.Substring(4, 2));
                int day = Convert.ToInt32(input.Substring(6, 2));
                try
                {
                    result = new DateTime(year, month, day);
                }
                catch
                {
                    return false;
                }
            }
            if (result.Year <= DateTime.Now.Year+10 && result.Year >= 1980)
            {
                // Falls within an acceptable date range, so try use it as a date
                dt = result;
                return true;
            }
            return false;
        }

        private static bool isNumeric(char c1)
        {
            if (c1 >= 48 && c1 < 58)
            {
                return true;
            }
            else return false;
        }

        private static bool isSymbol(char c1)
        {
            if ((c1 >= 32 && c1 < 48) || (c1 >= 58 && c1 < 65) || (c1 >= 91 && c1 < 97) || (c1 >= 123 && c1 < 127))
            {
                return true;
            }
            else return false;
        }

        /// <summary>
        /// Checks if the provided string matches the format specified
        /// d = digit
        /// a = alphanumeric
        /// s = symbol
        /// * = any
        /// </summary>
        /// <param name="source"></param>
        /// <param name="format"></param>
        /// <returns></returns>
        private static bool isMatch(string source, string format = "ddddsddsdd")
        {
            if (source.Length < format.Length) return false;
            bool state = true;
            for (int i = 0; i < format.Length; i++)
            {
                if (format[i] == 'd')
                {
                    if (!isNumeric(source[i]))
                    {
                        return false;
                    }
                }
                else if (format[i] == 's')
                {
                    if (!isSymbol(source[i]))
                    {
                        return false;
                    }
                }
            }

            return state;
        }

    }
}