aswi20220x00-gitlab/Backend/Core/Services/AnnotationService/AnnotationServiceEF.cs @ 3c185841

using Core.Contexts;
using Core.Entities;
using Models.Annotations;
using Models.Enums;
using Serilog;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using AutoMapper;
using Models.Tags;
using Ganss.XSS;
using HtmlAgilityPack;
using System.Text.RegularExpressions;

namespace Core.Services.AnnotationService
{
    public class AnnotationServiceEF : IAnnotationService
    {
        private readonly DatabaseContext context;
        private readonly ILogger logger;
        private readonly IMapper mapper;

        public AnnotationServiceEF(DatabaseContext context, ILogger logger, IMapper mapper)
        {
            this.context = context;
            this.logger = logger;
            this.mapper = mapper;
        }

        public void CreateDocumentAnnotations(AnnotationsAddRequest request, Guid clientUserId)
        {
            User addingUser = context.Users.Single(u => u.Id == clientUserId);

            // Check the documents exist
            var documents = context.Documents.Where(d => request.DocumentIdList.Contains(d.Id)).ToList();
            if (documents.Count() != request.DocumentIdList.Count)
            {
                logger.Information($"Received a non-existent Document ID when assigning documents to users");
                throw new InvalidOperationException($"{request.DocumentIdList.Count - documents.Count()} of the received documents do not exist");
            }

            var users = context.Users.Where(u => request.UserIdList.Contains(u.Id)).ToList();
            foreach (var user in users)
            {
                var userAnnotatedDocuments = context.Annotations.Where(a => a.User == user).Select(a => a.Document).ToList();
                foreach (var doc in documents)
                {
                    if (userAnnotatedDocuments.Contains(doc))
                    {
                        logger.Information($"User {user.Username} has already been assigned the document {doc.Id}, ignoring");
                        continue;
                    }

                    context.Annotations.Add(new Annotation()
                    {
                        User = user,
                        UserAssigned = addingUser,
                        DateAssigned = DateTime.Now,
                        DateLastChanged = DateTime.Now,
                        Document = doc,
                        State = EState.NEW,
                        Note = ""
                    });
                }
            }

            context.SaveChanges();
        }

        public AnnotationListResponse GetUserAnnotations(Guid userId)
        {
            var annotations = context.Annotations.Where(a => a.User.Id == userId).Include(a => a.Document).ToList();
            var documentIds = annotations.Select(a => a.Document.Id).ToList();
            var documents = context.Documents.Where(d => documentIds.Contains(d.Id));
            var infos = new List<AnnotationListInfo>();

            var annotationsDocuments = annotations.Zip(documents, (a, d) => new { Annotation = a, Document = d });
            foreach (var ad in annotationsDocuments)
            {
                infos.Add(new AnnotationListInfo()
                {
                    AnnotationId = ad.Annotation.Id,
                    DocumentName = ad.Document.Name,
                    State = ad.Annotation.State
                });
            }

            return new AnnotationListResponse()
            {
                Annotations = infos
            };
        }

        public AnnotationInfo GetAnnotation(Guid annotationId, Guid userId, ERole userRole)
        {
            var annotation = context.Annotations
                .Where(a => a.Id == annotationId)
                .Include(a => a.User)
                .Include(a => a.Document).ThenInclude(d => d.Content)
                .First();

            if (userRole < ERole.ADMINISTRATOR)
            {
                if (annotation.User.Id != userId)
                {
                    throw new UnauthorizedAccessException($"User {userId} does not have assigned annotation {annotationId}");
                }
            }

            var documentContent = context.Documents.Where(d => d.Id == annotation.Document.Id).Select(d => d.Content).First();
            var preprocessingResult = PreprocessHTML(documentContent.Content);

            // We probably cannot use AutoMapper since we are dealing with too many different entities
            AnnotationInfo annotationInfo = new()
            {
                SourceDocumentContent = documentContent.Content,
                DocumentToRender = preprocessingResult.docToRender,
                TagStartPositions = preprocessingResult.openingTagPositions,
                TagLengths = preprocessingResult.openingTagLengths,
                Note = annotation.Note,
                State = annotation.State,
                Type = IsHtml(documentContent.Content) ? EDocumentType.HTML : EDocumentType.TEXT
            };

            var tags = context.AnnotationTags.Where(at => at.Annotation.Id == annotationId)
                .Include(at => at.Tag).ThenInclude(t => t.Category)
                .Include(at => at.SubTag)
                .ToList();

            foreach (var tag in tags)
            {
                var tagInstance = mapper.Map<TagInstanceInfo>(tag);
                annotationInfo.TagInstances.Add(tagInstance);
            }

            return annotationInfo;
        }

        private (string docToRender, int[] openingTagPositions, int[] openingTagLengths, int[] closingTagPositions, int[] closingTagLengths) PreprocessHTML(string htmlSource)
        {
            var docOriginal = new HtmlDocument();
            docOriginal.LoadHtml(htmlSource);
            var docToEdit = new HtmlDocument();
            docToEdit.LoadHtml(htmlSource);

            string idAttributeName = "aswi-tag-id";

            var descendantsOriginal = docOriginal.DocumentNode.DescendantsAndSelf();
            var descendantsToEdit = docToEdit.DocumentNode.DescendantsAndSelf();

            List<int> tagStartPositions = new();
            List<int> tagStartLengths = new();


            List<int> tagClosingPositions = new();
            List<int> tagClosingLengths = new();

            int currentId = 0;

            var zipped = descendantsOriginal.Zip(descendantsToEdit, (orig, toEdit) => new { Original = orig, ToEdit = toEdit });
            foreach (var node in zipped)
            {
                var originalNode = node.Original;
                var toEditNode = node.ToEdit;

                if (originalNode.Name.Contains("#"))
                {
                    continue;
                }

                tagStartPositions.Add(originalNode.OuterStartIndex);
                tagStartLengths.Add(originalNode.OuterStartIndex - originalNode.InnerStartIndex);
                currentId = tagStartPositions.Count - 1;
                toEditNode.Attributes.Add(idAttributeName, currentId.ToString());

                tagClosingPositions.Add(originalNode.InnerStartIndex + originalNode.InnerLength);
                tagClosingLengths.Add((originalNode.OuterStartIndex + originalNode.OuterLength) - (originalNode.InnerStartIndex + originalNode.InnerLength));
            }

            string docToRender = docToEdit.DocumentNode.OuterHtml;
            HtmlSanitizer sanitizer = new HtmlSanitizer();
            sanitizer.AllowedAttributes.Clear();
            sanitizer.AllowedAttributes.Add(idAttributeName);

            docToRender = sanitizer.Sanitize(docToRender);

            return (docToRender, tagStartPositions.ToArray(), tagStartLengths.ToArray(), tagClosingPositions.ToArray(), tagClosingLengths.ToArray());
        }

        // TODO temporary
        private bool IsHtml(string text)
        {
            return text.Contains("<!DOCTYPE html>");
        }
    }
}