using Microsoft.SharePoint.Client;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Xml;

namespace ConfluenceToSharePointMigrator
{
    class HTMLFileProcess
    {
        /// <summary>
        /// Get the page name from either html file name or title from the html content
        /// </summary>
        /// <param name="pageName">file name of html</param>
        /// <param name="htmlFile">html file path</param>
        /// <returns></returns>
        public string SharePointPageNameFromHtml(string pageName, string htmlFile)
        {
            int fileNamePosition = pageName.LastIndexOf('_');

            pageName = pageName.Replace("---", "@$");
            pageName = pageName.Replace("-", " ");

            if (pageName.Contains('_'))
                fileNamePosition = pageName.LastIndexOf('_');
            else
                fileNamePosition = pageName.LastIndexOf('.');
            pageName = pageName.Replace(pageName.Substring(fileNamePosition, pageName.Length - fileNamePosition), "").Replace("@$", " - ");
            return pageName;
        }

        /// <summary>
        /// Remove the unwanted content like header, author. 
        /// </summary>
        /// <param name="fileContent">html file content</param>
        /// <returns></returns>
        public string FrameHTMLContentForSharePointPage(string fileContent)
        {
            //Remove main-header
            Regex headerPattern = new Regex(@"<div id=\""content\"" class=\""view\""(.*?\n.*?)*.*?");
            string headerContent = headerPattern.Replace(fileContent, "");
            headerPattern = new Regex(@"<div id=\""main-header(.*?\n.*?)*.*?");
            foreach (Match match in headerPattern.Matches(headerContent))
            {
                fileContent = fileContent.Replace(match.ToString(), "");
            }

            //Remove created and updated by content
            fileContent = Regex.Replace(fileContent, "Created by <span class='author'>.*?\\d\\d, \\d\\d\\d\\d", "");

            //Remove title 
            fileContent = Regex.Replace(fileContent, "<title>.*?</title>", "");

            //Remove attachment content section
            Regex attachmentPattern = new Regex("<div class=\"pageSection group\">(.*?\n.*?)*.*?");
            fileContent = attachmentPattern.Replace(fileContent, "</div></div></div></body></html>");

            //Remove the document generated information
            fileContent = Regex.Replace(fileContent, "<p>Document generated by Confluence on.*?</p>", "");
            fileContent = Regex.Replace(fileContent, "<div id=\"footer-logo\"><a href=.*?</div>", "");

            //Add strong tag for table header.
            fileContent = fileContent.Replace("class=\"confluenceTh\">", "class=\"confluenceTh\"><strong>");
            fileContent = fileContent.Replace("<th>", "<th><strong>");
            //fileContent = fileContent.Replace("class=\"confluenceTh\"","");
            //fileContent = fileContent.Replace("<th style=\"text-align: center;\" class=\"confluenceTh\">", "<th class=\"confluenceTh\"><strong>");
            //fileContent = fileContent.Replace("<th colspan=\"1\" class=\"confluenceTh\">", "<th colspan=\"1\" class=\"confluenceTh\"><strong>");
            fileContent = fileContent.Replace("</th>", "</strong></th>");

            //Add table row alignment as left if its single row.
            foreach (Match rowMatch in Regex.Matches(fileContent, "<tbody><tr.*?</tbody>"))
            {
                if (Regex.Matches(rowMatch.ToString(), "<tr").Count == 1)
                    fileContent = fileContent.Replace(rowMatch.ToString(), rowMatch.ToString().Replace("<div class=\"content-wrapper\">", "<div class=\"content-wrapper\" align=\"left\">"));
            }
            return fileContent;
        }

        /// <summary>
        /// Upload the file or image. Replace the uploaded url in html file.
        /// </summary>
        /// <param name="fileContent"></param>
        /// <returns></returns>
        public string UploadImageURLToHtml(string _fileContent, string _ConfluencePath, string _sharePointSiteURL, ClientContext _ctx)
        {
            Console.WriteLine("   - Image upload");
            Migration upload = new Migration();
            Regex imageFile = new Regex(" src=\"attachments/.*?\"");
            foreach (Match imageSrc1 in imageFile.Matches(_fileContent))
            {
                string imageSrc = imageSrc1.ToString();
                string imageLocation = imageSrc.ToString().Replace(" src=\"", "").Replace("?width=226","").Replace("?height=250\"", "").Replace("\"", "").Replace("?effects=drop-shadow","").Replace("width=917","").Replace("height=917","");
                
                imageLocation = Regex.Replace(imageLocation, ".png\\?.*", ".png");
                if (imageLocation.Contains('.'))
                {
                    //Upload image to SharePoint
                    upload.SharePointFileUpload(Path.Combine(_ConfluencePath, imageLocation.Replace("/","\\")), _ctx);
                    //Replace u-ploaded image URL
                    string uploadedURL = string.Empty;
                    string thumbnailURL = string.Empty;
                    string thumbnailURLInHtml = string.Empty;

                    if (imageSrc.ToString().Contains("src"))
                        uploadedURL = " src=\"" + _sharePointSiteURL + "/Shared%20Documents" + imageLocation.Remove(0, imageLocation.LastIndexOf('/')) + "?height=250\"";
                    
                    _fileContent = _fileContent.Replace(imageSrc.ToString(), uploadedURL);
                    if (!String.IsNullOrEmpty(thumbnailURL))
                        _fileContent = _fileContent.Replace(thumbnailURLInHtml, thumbnailURL);
                }
            }
            return _fileContent;
        }
    }
}