DeviantArtProvider.cs

// Copyright (c) Alden Wu <aldenwu0@gmail.com>. Licensed under the MIT Licence.
// See the LICENSE file in the repository root for full licence text.

using System.Net;
using System.Net.Http;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using DailyDesktop.Core.Configuration;
using DailyDesktop.Core.Providers;
using static System.Net.WebRequestMethods;

namespace DailyDesktop.Providers.DeviantArt
{
    public class DeviantArtProvider : IProvider
    {
        private const string IMAGE_URI_PATTERN = "(?<=(<img alt=(.*?)src=\"))(.*?)(?=(\"))";
        private const string AUTHOR_PATTERN = "(?<=<span property=\"creditText\".*?>).*?(?= on DeviantArt</span>)";
        private const string TITLE_PATTERN = "(?<=<h1.*?>)(.*?)(?=</h1>)";
        private const string TITLE_URI_PATTERN = "(?<=href=\")https://www.deviantart.com/([^\"]*?)/art/([^\"]*?)(?=\")";
        private const string DESCRIPTION_PATTERN = "(?<=(<div><div class=\"legacy-journal[^\"]*\">))(.*?)(?=(</div>))";

        public string DisplayName => "DeviantArt";
        public string Description => "Fetches one of DeviantArt's currently " +
            "featured piece from its Daily Deviations, a collection of art " +
            "handpicked by the DeviantArt community and staff. These artworks " +
            "highlight the best of DeviantArt from a wide variety of genres.";
        public string SourceUri => "https://www.deviantart.com/daily-deviations";

        public async Task ConfigureWallpaperAsync(HttpClient client, IPublicWallpaperConfiguration wallpaperConfig, CancellationToken cancellationToken)
        {
            // Search for image page URI from daily deviation page

            string dailyDeviationHtml = await client.GetStringAsync(SourceUri, cancellationToken);

            string titleUri = Regex.Match(dailyDeviationHtml, TITLE_URI_PATTERN).Value;
            if (string.IsNullOrWhiteSpace(titleUri))
                throw new ProviderException("Didn't find an image page URI.");

            // Scrape info from image page

            string pageHtml = await client.GetStringAsync(titleUri, cancellationToken);

            string imageUri = Regex.Match(pageHtml, IMAGE_URI_PATTERN).Value;
            if (string.IsNullOrWhiteSpace(imageUri))
                throw new ProviderException("Didn't find an image URI.");

            string author = Regex.Match(pageHtml, AUTHOR_PATTERN).Value;
            string authorUri = Regex.Match(titleUri, "https://www.deviantart.com/.*?/").Value;
            string title = Regex.Match(pageHtml, TITLE_PATTERN).Value;
            string description = Regex.Replace(WebUtility.HtmlDecode(Regex.Match(pageHtml, DESCRIPTION_PATTERN).Value), "<([^<>]*?)>", "");

            await wallpaperConfig.SetImageUriAsync(imageUri, cancellationToken);
            await wallpaperConfig.SetAuthorAsync(author, cancellationToken);
            await wallpaperConfig.SetAuthorUriAsync(authorUri, cancellationToken);
            await wallpaperConfig.SetTitleAsync(title, cancellationToken);
            await wallpaperConfig.SetTitleUriAsync(titleUri, cancellationToken);
            await wallpaperConfig.SetDescriptionAsync(description, cancellationToken);
        }
    }
}