using PDF_Master.Properties;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace PDF_Master.Helper
{
    public static class FileComparisonHelper
    {
#if DEBUG
        public static string URI_AppXml = "http://test-pdf-pro.kdan.cn:3021/downloads/pdfreaderprocast_win_en_Us.xml";
#else
        public static string URI_AppXml = "https://www.pdfreaderpro.com/downloads/pdfreaderprocast_win_en_Us.xml";
#endif

        private static string OCRmodelMD5 = "";

        /// <summary>
        /// 获取文件MD5
        /// </summary>
        /// <param name="folderPath">文件路径</param>
        /// <returns></returns>
        public static string CalculateFileMD5(string filePath)
        {
            using (var md5 = MD5.Create())
            {
                using (var stream = File.OpenRead(filePath))
                {
                    var hash = md5.ComputeHash(stream);
                    return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
                }
            }
        }

        /// <summary>
        /// 获取文件夹MD5
        /// </summary>
        /// <param name="folderPath">文件路径</param>
        /// <returns></returns>
        public static string CalculateFolderMD5(string folderPath)
        {
            var files = Directory.GetFiles(folderPath, "*", SearchOption.AllDirectories);
            using (var md5 = MD5.Create())
            {
                //遍历文件夹获取，各个文件夹MD5合并为一个MD5
                foreach (var file in files)
                {
                    var fileHash = CalculateFileMD5(file);
                    var hashBytes = Encoding.UTF8.GetBytes(fileHash);
                    md5.TransformBlock(hashBytes, 0, hashBytes.Length, hashBytes, 0);
                }

                md5.TransformFinalBlock(new byte[0], 0, 0);
                var hash = md5.Hash;
                return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
            }
        }


        /// <summary>
        /// 判断OCR资源是否存在
        /// </summary>
        public static bool OCRModelItExist()
        {

            string folderPath = System.IO.Path.Combine(App.CurrentPath, "OCREngine");
            if (Directory.Exists(folderPath))
            {
                Settings.Default.AppProperties.OCRmodelMD5 = "65d21a699138c194f06a8640dd40a901";
                Settings.Default.AppProperties.OCRFile_Url = "http://test-pdf-pro.kdan.cn:3021/downloads/OCREngine.zip";
                if (!Getpdfreaderprocast())
                {
                    return false;
                }
                string folderMD5 = "";
                if (string.IsNullOrEmpty(OCRmodelMD5))
                {
                    folderMD5 = FileComparisonHelper.CalculateFolderMD5(folderPath);
                }
                else {
                    folderMD5 = OCRmodelMD5;
                }
                if (folderMD5 == Settings.Default.AppProperties.OCRmodelMD5)
                {
                    OCRmodelMD5 = folderMD5;
                    return true;
                }
            }
            else
            {
                Console.WriteLine("文件夹不存在");
            }
            if (!Getpdfreaderprocast())
            {
                return false;
            }
            return false;
        }

        /// <summary>
        /// 删除OCR资源
        /// </summary>
        public static void RemoveOCRModel()
        {
            try
            {
                string folderPath = System.IO.Path.Combine(App.CurrentPath, "OCREngine");
                if (Directory.Exists(folderPath))
                {
                    Directory.Delete(folderPath, true);
                }
                string folderzipPath = System.IO.Path.Combine(App.CurrentPath, "OCREnginezip");
                if (Directory.Exists(folderzipPath))
                {
                    Directory.Delete(folderzipPath, true);
                }
            }
            catch
            {

            }
        }

        /// <summary>
        /// 获取OCR下载信息
        /// </summary>
        /// <returns></returns>
        public static bool Getpdfreaderprocast()
        {
            if (string.IsNullOrEmpty(Settings.Default.AppProperties.OCRFile_Url) && string.IsNullOrEmpty(Settings.Default.AppProperties.OCRmodelMD5))
            {
                string folder = System.IO.Path.Combine(App.CurrentPath, "AppXml");
                DirectoryInfo directory = new DirectoryInfo(folder);
                try
                {
                    if (!directory.Exists)
                    {
                        directory.Create();

                    }

                    string FileNameAppxml = folder + "\\" + "appxml" + ".xml";
                    //下载What`s new
                    WebClient client = new WebClient();
                    client.DownloadFile(URI_AppXml, FileNameAppxml);
                    XmlDocument xmlDoc = new XmlDocument();
                    xmlDoc.Load(FileNameAppxml);
                    XmlNode root = xmlDoc.DocumentElement;
                    //获取OCR信息父节点
                    XmlNode itemNodes = root.SelectSingleNode("channel/item/ocrenclosure");
                    //获取OCR信息子节点个数
                    int siblingCount = 0;
                    foreach (XmlNode itemNode in itemNodes)
                    {
                        XmlNode parentNode = itemNode.ParentNode;
                        siblingCount = parentNode.ChildNodes.Count;
                    }
                    //遍历子节点
                    for (int i = 0; i < siblingCount; i++)
                    {
                        //对应子节点对象
                        XmlNode itemNode = root.SelectSingleNode("channel/item/ocrenclosure/ocrenclosure" + i);
                        XmlAttribute ocrstartversionUrlAttribute = itemNode.Attributes["sparkle:startversion"];
                        XmlAttribute ocrendversionUrlAttribute = itemNode.Attributes["sparkle:endversion"];
                        //版本号区间
                        Version ocrendversion = new Version(ocrendversionUrlAttribute.Value);
                        Version ocrstartversion = new Version(ocrstartversionUrlAttribute.Value);
                        Version Appversion = new Version(App.Version);
                        if (ocrstartversion <= Appversion && Appversion <= ocrendversion)
                        {
                            //获取OCR下载链接
                            XmlAttribute ocrUrlAttribute = itemNode.Attributes["ocrurl"];
                            Settings.Default.AppProperties.OCRFile_Url = ocrUrlAttribute?.Value;
                            //获取OCRMD5
                            XmlAttribute ocrUrlAttributemd5 = itemNode.Attributes["ocrmd5"];
                            Settings.Default.AppProperties.OCRmodelMD5 = ocrUrlAttributemd5?.Value;
                            return true;
                        }
                    }
                    return false;
                }
                catch { return false; }
            }
            return true;
        }
    }
}