using System;
using System.Collections.Generic;
using System.IO;
using HtmlAgilityPack;
using Umbraco.Core;
using Umbraco.Core.Exceptions;
using Umbraco.Core.IO;
using Umbraco.Core.Logging;
using Umbraco.Core.Media;
using Umbraco.Core.Models;
using Umbraco.Core.Services;
using Umbraco.Core.Strings;
using Umbraco.Web.Routing;
using Umbraco.Web.Templates;

namespace Umbraco.Web.PropertyEditors
{
    public sealed class RichTextEditorPastedImages
    {
        private readonly IUmbracoContextAccessor _umbracoContextAccessor;
        private readonly ILogger _logger;
        private readonly IIOHelper _ioHelper;
        private readonly IMediaService _mediaService;
        private readonly IContentTypeBaseServiceProvider _contentTypeBaseServiceProvider;
        private readonly IMediaFileSystem _mediaFileSystem;
        private readonly IShortStringHelper _shortStringHelper;
        private readonly IPublishedUrlProvider _publishedUrlProvider;

        const string TemporaryImageDataAttribute = "data-tmpimg";

        public RichTextEditorPastedImages(IUmbracoContextAccessor umbracoContextAccessor, ILogger logger, IIOHelper ioHelper, IMediaService mediaService, IContentTypeBaseServiceProvider contentTypeBaseServiceProvider, IMediaFileSystem mediaFileSystem, IShortStringHelper shortStringHelper, IPublishedUrlProvider publishedUrlProvider)
        {
            _umbracoContextAccessor = umbracoContextAccessor ?? throw new ArgumentNullException(nameof(umbracoContextAccessor));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
            _ioHelper = ioHelper;
            _mediaService = mediaService ?? throw new ArgumentNullException(nameof(mediaService));
            _contentTypeBaseServiceProvider = contentTypeBaseServiceProvider ?? throw new ArgumentNullException(nameof(contentTypeBaseServiceProvider));
            _mediaFileSystem = mediaFileSystem;
            _shortStringHelper = shortStringHelper;
            _publishedUrlProvider = publishedUrlProvider;
        }

        /// <summary>
        /// Used by the RTE (and grid RTE) for drag/drop/persisting images
        /// </summary>
        /// <param name="html"></param>
        /// <param name="mediaParentFolder"></param>
        /// <param name="userId"></param>
        /// <returns></returns>
        public string FindAndPersistPastedTempImages(string html, Guid mediaParentFolder, int userId, IImageUrlGenerator imageUrlGenerator)
        {
            // Find all img's that has data-tmpimg attribute
            // Use HTML Agility Pack - https://html-agility-pack.net
            var htmlDoc = new HtmlDocument();
            htmlDoc.LoadHtml(html);

            var tmpImages = htmlDoc.DocumentNode.SelectNodes($"//img[@{TemporaryImageDataAttribute}]");
            if (tmpImages == null || tmpImages.Count == 0)
                return html;

            // An array to contain a list of URLs that
            // we have already processed to avoid dupes
            var uploadedImages = new Dictionary<string, GuidUdi>();

            foreach (var img in tmpImages)
            {
                // The data attribute contains the path to the tmp img to persist as a media item
                var tmpImgPath = img.GetAttributeValue(TemporaryImageDataAttribute, string.Empty);

                if (string.IsNullOrEmpty(tmpImgPath))
                    continue;

                var absoluteTempImagePath = _ioHelper.MapPath(tmpImgPath);
                var fileName = Path.GetFileName(absoluteTempImagePath);
                var safeFileName = fileName.ToSafeFileName(_shortStringHelper);

                var mediaItemName = safeFileName.ToFriendlyName();
                IMedia mediaFile;
                GuidUdi udi;

                if (uploadedImages.ContainsKey(tmpImgPath) == false)
                {
                    if (mediaParentFolder == Guid.Empty)
                        mediaFile = _mediaService.CreateMedia(mediaItemName, Constants.System.Root, Constants.Conventions.MediaTypes.Image, userId);
                    else
                        mediaFile = _mediaService.CreateMedia(mediaItemName, mediaParentFolder, Constants.Conventions.MediaTypes.Image, userId);

                    var fileInfo = new FileInfo(absoluteTempImagePath);

                    var fileStream = fileInfo.OpenReadWithRetry();
                    if (fileStream == null) throw new InvalidOperationException("Could not acquire file stream");
                    using (fileStream)
                    {
                        mediaFile.SetValue(_mediaFileSystem, _shortStringHelper, _contentTypeBaseServiceProvider, Constants.Conventions.Media.File, safeFileName, fileStream);
                    }

                    _mediaService.Save(mediaFile, userId);

                    udi = mediaFile.GetUdi();
                }
                else
                {
                    // Already been uploaded & we have it's UDI
                    udi = uploadedImages[tmpImgPath];
                }

                // Add the UDI to the img element as new data attribute
                img.SetAttributeValue("data-udi", udi.ToString());

                // Get the new persisted image url
                var mediaTyped = _umbracoContextAccessor?.UmbracoContext?.Media.GetById(udi.Guid);
                if (mediaTyped == null)
                    throw new PanicException($"Could not find media by id {udi.Guid} or there was no UmbracoContext available.");

                var location = mediaTyped.Url(_publishedUrlProvider);

                // Find the width & height attributes as we need to set the imageprocessor QueryString
                var width = img.GetAttributeValue("width", int.MinValue);
                var height = img.GetAttributeValue("height", int.MinValue);

                if (width != int.MinValue && height != int.MinValue)
                {
                    location = imageUrlGenerator.GetImageUrl(new ImageUrlGenerationOptions(location) { ImageCropMode = "max", Width = width, Height = height });
                }

                img.SetAttributeValue("src", location);

                // Remove the data attribute (so we do not re-process this)
                img.Attributes.Remove(TemporaryImageDataAttribute);

                // Add to the dictionary to avoid dupes
                if (uploadedImages.ContainsKey(tmpImgPath) == false)
                {
                    uploadedImages.Add(tmpImgPath, udi);

                    // Delete folder & image now its saved in media
                    // The folder should contain one image - as a unique guid folder created
                    // for each image uploaded from TinyMceController
                    var folderName = Path.GetDirectoryName(absoluteTempImagePath);
                    try
                    {
                        Directory.Delete(folderName, true);
                    }
                    catch (Exception ex)
                    {
                        _logger.Error(typeof(HtmlImageSourceParser), ex, "Could not delete temp file or folder {FileName}", absoluteTempImagePath);
                    }
                }
            }

            return htmlDoc.DocumentNode.OuterHtml;
        }
    }
}