using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using DiffPlex;
using System.IO.Packaging;
using System.Text.RegularExpressions;
using System.Linq;
using Microsoft.Office.Interop.Word;


namespace wispro.sp.utility
{
    /// <summary>
    /// 比较两个Docx文档中文字的不同
    /// </summary>
    public class CompareDocx
    {
        /// <summary>
        /// 原文档路径
        /// </summary>
        public string oldDocument { get; set; }

        /// <summary>
        /// 修订后文档路径
        /// </summary>
        public string newDocument { get; set; }

        /// <summary>
        /// 总的修改比率
        /// </summary>
        public double diffRate
        {
            get
            {
                return ((double)_DeleteCount + (double)_InsertCount) / (double)_oldDocCount;
            }
        }

        private int _oldDocCount;
        /// <summary>
        /// 原文档字数
        /// </summary>
        public int oldDocumentCount
        {
            get { return _oldDocCount; }
        }

        private int _newDocCount;
        /// <summary>
        /// 修订后文档字数
        /// </summary>
        public int newDocumentCount
        {
            get { return _newDocCount; }
        }

        private int _DeleteCount;
        /// <summary>
        /// 修订后文档相比原文档删除的字数
        /// </summary>
        public int DeleteCount
        {
            get
            {
                return _DeleteCount;
            }
        }

        private int _InsertCount;

        /// <summary>
        /// 修改后文档相比原文档插入的字数
        /// </summary>
        public int InsertCount
        {
            get
            {
                return _InsertCount;
            }
        }

        private double _EditCount;
        /// <summary>
        /// 修订处数量
        /// </summary>
        public double EditCount
        {
            get
            {
                return _EditCount;
            }
        }



        private string _CompareResultString;
        /// <summary>
        /// 包括修订文字版本的文档
        /// </summary>
        public string CompareResultString
        {
            get
            {
                return _CompareResultString;
            }
        }

        /// <summary>
        /// 比较两个文档
        /// </summary>
        /// <param name="oldFile"></param>
        /// <param name="newFile"></param>
        public void Compare(string oldFile, string newFile)
        {
            this.oldDocument = oldFile;
            this.newDocument = newFile;

            Compare();
        }

        /// <summary>
        /// 比较两个文档
        /// </summary>
        /// <exception cref="ApplicationException"></exception>
        public void Compare()
        {
            if (!System.IO.File.Exists(this.oldDocument) || !System.IO.File.Exists(this.newDocument))
            {
                throw new ApplicationException("指定的文件不存在！");
            }

            var differ = new Differ();
            string oldtext = "";
            if (this.oldDocument.EndsWith(".doc"))
            {
                oldtext = GetDocTxt(this.oldDocument);
            }
            else
            {
                oldtext = GetDocxTxt(this.oldDocument);
            }

            _oldDocCount = oldtext.Length;

            string newtext = "";
            if (this.newDocument.EndsWith(".doc"))
            {
                newtext = GetDocTxt(this.newDocument);
            }
            else
            {
                newtext = GetDocxTxt(this.newDocument);
            }
            _newDocCount = newtext.Length;

            var diff = differ.CreateCharacterDiffs(oldtext, newtext, true);
            _EditCount = diff.DiffBlocks.Count;

            int iDeff = 0;
            int lastPos = 0;

            _CompareResultString = "<p>";
            string lastResult = "";
            foreach (var change in diff.DiffBlocks)
            {
                iDeff += change.DeleteCountA + change.InsertCountB;
                _DeleteCount += change.DeleteCountA;
                _InsertCount += change.InsertCountB;

                lastResult += oldtext.Substring(lastPos, change.DeleteStartA - lastPos);
                _CompareResultString += oldtext.Substring(lastPos, change.DeleteStartA - lastPos);
                lastPos = change.DeleteStartA + change.DeleteCountA;


                if (change.DeleteCountA > 0)
                {
                    _CompareResultString += $"<strike  style=\"text-decoration: line-through; color: red;\">{oldtext.Substring(change.DeleteStartA, change.DeleteCountA)}</strike>";
                }

                if (change.InsertCountB > 0)
                {
                    _CompareResultString += $"<u style=\"text-decoration: underline; color: blue;\">{newtext.Substring(change.InsertStartB, change.InsertCountB)}</u>";
                    lastResult += newtext.Substring(change.InsertStartB, change.InsertCountB);
                }
            }

            lastResult += oldtext.Substring(lastPos);
            _CompareResultString += oldtext.Substring(lastPos);
            _CompareResultString = _CompareResultString.Replace("\r\n", "</p>\r\n<p>") + "</p>";
            
        }

        private string GetDocTxt(string filePath)
        {
            Application word = null;
            Document doc = null;
            string content = string.Empty;

            try
            {
                // 创建Word应用实例
                word = new Application();
                // 打开Word文档
                System.IO.FileInfo fileInfo = new System.IO.FileInfo(filePath);
                doc = word.Documents.Open(fileInfo.FullName);
                // 读取文档内容
                content = doc.Content.Text;

                List<string> lines = content.Split("\r").ToList();
                return List2String(lines);

            }
            catch (Exception ex)
            {
                throw new Exception($"读取Word文档时发生错误: {ex.Message}");
            }
            finally
            {
                // 关闭文档
                if (doc != null)
                {
                    doc.Close();
                    #pragma warning disable CA1416 // 验证平台兼容性
                    System.Runtime.InteropServices.Marshal.ReleaseComObject(doc);
                    #pragma warning restore CA1416 // 验证平台兼容性
                }
                // 退出Word应用
                if (word != null)
                {
                    word.Quit();
                    #pragma warning disable CA1416 // 验证平台兼容性
                    System.Runtime.InteropServices.Marshal.ReleaseComObject(word);
                    #pragma warning restore CA1416 // 验证平台兼容性
                }
            }


        }

        private string GetDocxTxt(string filepath)
        {
            var oldtext = getDocxMainXml(filepath);
            var oldlines = ExtractWPTextFromXml(oldtext);
            oldtext = List2String(oldlines);

            return oldtext;
        }

        private string List2String(List<string> lines)
        {
            StringBuilder sb = new StringBuilder();
            foreach (var line in lines)
            {
                if (!string.IsNullOrEmpty(line))
                {
                    sb.Append(line.Trim() + "\r\n");
                }
            }

            return sb.ToString();
        }

        private string getDocxMainXml(string filePath)
        {
            string text = string.Empty;
            using (Package package = Package.Open(filePath, FileMode.Open))
            {
                var Parts = package.GetParts();

                foreach (var part in Parts)
                {
                    if (part.ContentType.StartsWith("application/vnd.openxmlformats-officedocument.wordprocessingml.document.main"))
                    {
                        using (Stream stream = part.GetStream())
                        {
                            StreamReader reader = new StreamReader(stream);
                            text = reader.ReadToEnd();
                            break;
                        }
                    }
                }

                return text;
            }
        }

        private List<string> ExtractWPTextFromXml(string xmlText)
        {
            List<string> lines = new List<string>();
            // 使用正则表达式匹配 <w:t> 标签的内容
            MatchCollection matches = Regex.Matches(xmlText, "(<w:p\\s.*?>|<w:p>)(.*?)</w:p>");

            foreach (Match match in matches)
            {
                lines.Add(ExtractWtTextFromXml(match.Groups[2].Value));
            }
            return lines;
        }

        private string ExtractWtTextFromXml(string xmlText)
        {
            // 使用正则表达式匹配 <w:t> 标签的内容
            MatchCollection matches = Regex.Matches(xmlText, "(<w:t\\s.*?>|<w:t>)(.*?)</w:t>");
            StringBuilder sb = new StringBuilder();
            foreach (Match match in matches)
            {
                sb.Append(match.Groups[2].Value);
            }
            return sb.ToString();
        }
    }
}