using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;
using System.Security;
using Kreta.Core.FileService.Configuration;

namespace Kreta.Core.FileService
{
    public class FileService : IFileService
    {
        private readonly IFileServiceConfiguration FileServiceConfiguration;

        public FileService(IFileServiceConfiguration fileServiceConfiguration)
        {
            FileServiceConfiguration = fileServiceConfiguration ?? throw new ArgumentNullException(nameof(fileServiceConfiguration));
        }

        //konfigból jobb lenne
        private readonly Dictionary<string, string> _allowedFileTypes =
        new Dictionary<string, string>() {
            { ".txt", "text/plain" },
            { ".pdf", "application/pdf" },
            { ".png", "image/png" },
            { ".bmp", "image/bmp" },
            { ".jpg", "image/jpeg" },
            { ".jpeg", "image/jpeg" },
            { ".xls", "application/vnd.ms-excel" },
            { ".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" },
            { ".doc", "application/msword" },
            { ".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document" },
            { ".xml", "text/xml" },
            { ".roz", "application/roz" },
            {".rar", "application/octet-stream"},
            {".zip", "application/x-zip-compressed"}
        };

        private Storage GetStorage(string storageName)
        {
            if (string.IsNullOrWhiteSpace(storageName))
            {
                throw new ArgumentException(nameof(storageName));
            }

            Storage storage = null;

            foreach (Storage storageElement in FileServiceConfiguration.Storages)
            {
                if (storageElement.Key.Equals(storageName, StringComparison.OrdinalIgnoreCase))
                {
                    storage = storageElement;
                    break;
                }
            }

            if (storage == null)
            {
                throw new Exception("Nem létező storage name van megadva!");
            }

            return storage;
        }

        public string WriteToFile(string base64EncodedContent, string storageName)
        {
            Storage storage = GetStorage(storageName);

            string newFileName = Guid.NewGuid().ToString();
            string directoryPath = System.IO.Path.Combine(GetFileSharePath(storage), System.IO.Path.Combine(newFileName.Split('-')[0].Substring(0, 4).Select(x => x.ToString()).ToArray()));

            try
            {
                Directory.CreateDirectory(directoryPath);
            }
            catch (Exception exception)
            {
                throw new Exception($"Hiba történt a mappa létrehozása során!", exception);
            }

            string filePath = System.IO.Path.Combine(directoryPath, newFileName);
            string[] parts = base64EncodedContent.Split(new string[] { ";", ":", "," }, StringSplitOptions.None);
            byte[] binaryFile = Convert.FromBase64String(parts[3]);

            AttachmentValidation(binaryFile.Length, storage.MaxFileSizeInBytes, _allowedFileTypes.FirstOrDefault(x => x.Value == parts[1]).Key);

            try
            {
                File.WriteAllBytes(filePath, binaryFile);
            }
            catch (Exception exception)
            {
                throw new Exception($"Hiba történt a fájl írása közben: {exception.Message}", exception);
            }

            return filePath;
        }

        public byte[] ReadFromFile(string filePath)
        {
            try
            {
                return File.ReadAllBytes(filePath);
            }
            catch (Exception exception)
            {
                throw new Exception($"Hiba történt a fájl olvasása közben: {exception.Message}", exception);
            }
        }

        public string ReadImage(string filePath, string fileExtension)
        {
            byte[] imageContent = ReadFromFile(filePath);

            if (imageContent != null)
            {
                return $"data:image/{fileExtension};base64,{Convert.ToBase64String(imageContent)}";
            }

            return null;
        }

        public string ReadAndResizeImage(string filePath, int width, int height)
        {
            byte[] imageContent = ReadFromFile(filePath);

            if (imageContent != null)
            {
                Image image = CreateImage(imageContent);

                return $"data:image/jpeg;base64,{Convert.ToBase64String(ResizeImage(image, width, height))}";
            }

            return null;
        }

        private Image CreateImage(byte[] pictureByteArray)
        {
            using (var memoryStream = new MemoryStream(pictureByteArray, 0, pictureByteArray.Length))
            {
                return Image.FromStream(memoryStream, true, true);
            }
        }

        private byte[] ResizeImage(Image image, int width, int height)
        {
            var destRect = new Rectangle(0, 0, width, height);

            using (var destImage = new Bitmap(width, height))
            {
                destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);

                using (var graphics = Graphics.FromImage(destImage))
                {
                    graphics.CompositingMode = CompositingMode.SourceCopy;
                    graphics.CompositingQuality = CompositingQuality.HighQuality;
                    graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
                    graphics.SmoothingMode = SmoothingMode.HighQuality;
                    graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;

                    using (var wrapMode = new ImageAttributes())
                    {
                        wrapMode.SetWrapMode(WrapMode.TileFlipXY);
                        graphics.DrawImage(image, destRect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, wrapMode);
                    }
                }

                using (var memoryStream = new MemoryStream())
                {
                    destImage.Save(memoryStream, ImageFormat.Jpeg);

                    return memoryStream.ToArray();
                }
            }
        }

        private void AttachmentValidation(long contentLength, int maxFileSizeInBytes, string contentType)
        {
            if (contentType == null)
            {
                throw new Exception("Nem tölthető fel a fájl, mert nincs kiterjesztése");
            }

            if (!_allowedFileTypes.ContainsKey(contentType))
            {
                throw new Exception("Nem megengedett a fájl formátuma!");
            }

            if (contentLength > maxFileSizeInBytes)
            {
                throw new Exception("Nem tölthető fel a fájl, mert túl nagy a mérete");
            }
        }

        private string GetFileSharePath(Storage storageElement)
        {
            string root = string.Empty;

            foreach (Configuration.Path path in storageElement.Paths)
            {
                root = path.Value;

                if (!HasEnoughFreeSpaceOnDisk(storageElement.MinimumRequiredFreeSpaceInBytes, root))
                {
                    throw new Exception("Nincs elég hely a tárolón!");
                }

                break;
            }

            if (string.IsNullOrWhiteSpace(root))
            {
                throw new Exception("A megosztott meghajtó nincs megadva!");
            }

            return root;
        }

        private bool HasEnoughFreeSpaceOnDisk(int minimumRequiredFreeSpaceInBytes, string path)
        {
            if (string.IsNullOrWhiteSpace(path))
            {
                throw new ArgumentException(nameof(path));
            }

            //Nem működik a megosztott mappával
            //TODO Imi: ellenőrizni, h létezik-e a megadott megosztott mappa
            /*if (!Directory.Exists(path))
            {
                throw new ArgumentNullException("Nem létezik a file share!");
            }*/

            long freeSpaceInBytes = 0, dummy1 = 0, dummy2 = 0;

            if (!GetDiskFreeSpaceEx(path, ref freeSpaceInBytes, ref dummy1, ref dummy2))
            {
                return false;
            }

            return freeSpaceInBytes > minimumRequiredFreeSpaceInBytes;
        }

        [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage"), SuppressUnmanagedCodeSecurity]
        [DllImport("Kernel32", SetLastError = true, CharSet = CharSet.Auto)]
        [return: MarshalAs(UnmanagedType.Bool)]
        private static extern bool GetDiskFreeSpaceEx
        (
            string lpszPath,
            ref long lpFreeBytesAvailable,
            ref long lpTotalNumberOfBytes,
            ref long lpTotalNumberOfFreeBytes
        );

        public void DeleteFile(string filePath)
        {
            try
            {
                File.Delete(filePath);
            }
            catch (Exception ex)
            {
                throw new Exception("A fájl törlése sikertelen!", ex);
            }
        }
    }
}