Add XMLTV guide content ETags

3 files changed, 215 insertions, 1 deletions

diff --git a/src/Jellyfin.LiveTv/Guide/GuideManager.cs b/src/Jellyfin.LiveTv/Guide/GuideManager.cs
index 556516674b..d59eb9c18f 100644
--- a/src/Jellyfin.LiveTv/Guide/GuideManager.cs
+++ b/src/Jellyfin.LiveTv/Guide/GuideManager.cs
@@ -6,6 +6,7 @@ using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
 using Jellyfin.Extensions;
 using Jellyfin.LiveTv.Configuration;
+using Jellyfin.LiveTv.Listings;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Controller.Dto;
 using MediaBrowser.Controller.Entities;
@@ -497,6 +498,13 @@ public class GuideManager : IGuideManager
 
             item.TrySetProviderId(EtagKey, info.Etag);
         }
+        else if (XmlTvProgramEtag.MatchesStored(info.Etag, item.GetProviderId(EtagKey)))
+        {
+            // XMLTV ETags are generated from the final ProgramInfo fields Jellyfin consumes,
+            // so an exact match means nothing relevant changed. Other providers stay on the
+            // field-by-field update path.
+            return (item, false, false);
+        }
 
         if (!string.Equals(info.ShowId, item.ShowId, StringComparison.OrdinalIgnoreCase))
         {
diff --git a/src/Jellyfin.LiveTv/Listings/XmlTvListingsProvider.cs b/src/Jellyfin.LiveTv/Listings/XmlTvListingsProvider.cs
index ec2e6cfcc9..622a1ac6fe 100644
--- a/src/Jellyfin.LiveTv/Listings/XmlTvListingsProvider.cs
+++ b/src/Jellyfin.LiveTv/Listings/XmlTvListingsProvider.cs
@@ -172,7 +172,29 @@ namespace Jellyfin.LiveTv.Listings
             var reader = new XmlTvReader(path, GetLanguage(info));
 
             return reader.GetProgrammes(channelId, startDateUtc, endDateUtc, cancellationToken)
-                        .Select(p => GetProgramInfo(p, info));
+                        .Select(p => GetProgramInfoWithEtag(p, info));
+        }
+
+        private ProgramInfo GetProgramInfoWithEtag(XmlTvProgram program, ListingsProviderInfo info)
+        {
+            var programInfo = GetProgramInfo(program, info);
+
+            if (XmlTvProgramEtag.TryCreate(programInfo, out var etag, out var reason))
+            {
+                programInfo.Etag = etag;
+            }
+            else
+            {
+                _logger.LogDebug(
+                    "Unable to create XMLTV program ETag for program {ProgramId} on channel {ChannelId} from {StartDate} to {EndDate}: {Reason}. The program will be treated as updated on each guide refresh.",
+                    programInfo.Id,
+                    programInfo.ChannelId,
+                    programInfo.StartDate,
+                    programInfo.EndDate,
+                    reason);
+            }
+
+            return programInfo;
         }
 
         private static ProgramInfo GetProgramInfo(XmlTvProgram program, ListingsProviderInfo info)
diff --git a/src/Jellyfin.LiveTv/Listings/XmlTvProgramEtag.cs b/src/Jellyfin.LiveTv/Listings/XmlTvProgramEtag.cs
new file mode 100644
index 0000000000..b128b0ff9c
--- /dev/null
+++ b/src/Jellyfin.LiveTv/Listings/XmlTvProgramEtag.cs
@@ -0,0 +1,184 @@
+#pragma warning disable CS1591
+
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using MediaBrowser.Controller.LiveTv;
+
+namespace Jellyfin.LiveTv.Listings
+{
+    internal static class XmlTvProgramEtag
+    {
+        internal const string Prefix = "xmltv-sha256-v1:";
+
+        internal static bool IsXmlTvEtag(string? etag)
+            => !string.IsNullOrWhiteSpace(etag)
+                && etag.StartsWith(Prefix, StringComparison.Ordinal);
+
+        // Returns true only when the incoming etag is XMLTV-style AND equals the stored value.
+        // The IsXmlTvEtag gate keeps other providers (e.g. Schedules Direct) on the
+        // field-by-field update path even if their etag strings happen to match.
+        internal static bool MatchesStored(string? incomingEtag, string? storedEtag)
+            => IsXmlTvEtag(incomingEtag)
+                && string.Equals(incomingEtag, storedEtag, StringComparison.OrdinalIgnoreCase);
+
+        internal static bool TryCreate(ProgramInfo programInfo, out string? etag, out string? reason)
+        {
+            etag = null;
+
+            if (string.IsNullOrWhiteSpace(programInfo.Id))
+            {
+                reason = "program id is empty";
+                return false;
+            }
+
+            if (string.IsNullOrWhiteSpace(programInfo.ChannelId))
+            {
+                reason = "channel id is empty";
+                return false;
+            }
+
+            if (programInfo.StartDate == default)
+            {
+                reason = "start date is empty";
+                return false;
+            }
+
+            if (programInfo.EndDate == default)
+            {
+                reason = "end date is empty";
+                return false;
+            }
+
+            if (programInfo.EndDate <= programInfo.StartDate)
+            {
+                reason = "end date is not after start date";
+                return false;
+            }
+
+            var builder = new StringBuilder(1024);
+
+            // Keep this list aligned with the ProgramInfo fields consumed by GuideManager.
+            AppendValue(builder, "schema", "xmltv-programinfo-v1");
+            AppendValue(builder, nameof(programInfo.Id), programInfo.Id);
+            AppendValue(builder, nameof(programInfo.ChannelId), programInfo.ChannelId);
+            AppendValue(builder, nameof(programInfo.Name), programInfo.Name);
+            AppendValue(builder, nameof(programInfo.OfficialRating), programInfo.OfficialRating);
+            AppendValue(builder, nameof(programInfo.Overview), programInfo.Overview);
+            AppendValue(builder, nameof(programInfo.StartDate), programInfo.StartDate);
+            AppendValue(builder, nameof(programInfo.EndDate), programInfo.EndDate);
+            AppendList(builder, nameof(programInfo.Genres), programInfo.Genres);
+            AppendValue(builder, nameof(programInfo.OriginalAirDate), programInfo.OriginalAirDate);
+            AppendValue(builder, nameof(programInfo.IsHD), programInfo.IsHD);
+            AppendValue(builder, nameof(programInfo.Audio), programInfo.Audio?.ToString());
+            AppendValue(builder, nameof(programInfo.CommunityRating), programInfo.CommunityRating);
+            AppendValue(builder, nameof(programInfo.IsRepeat), programInfo.IsRepeat);
+            AppendValue(builder, nameof(programInfo.EpisodeTitle), programInfo.EpisodeTitle);
+            AppendValue(builder, nameof(programInfo.ImagePath), programInfo.ImagePath);
+            AppendValue(builder, nameof(programInfo.ImageUrl), programInfo.ImageUrl);
+            AppendValue(builder, nameof(programInfo.ThumbImageUrl), programInfo.ThumbImageUrl);
+            AppendValue(builder, nameof(programInfo.LogoImageUrl), programInfo.LogoImageUrl);
+            AppendValue(builder, nameof(programInfo.BackdropImageUrl), programInfo.BackdropImageUrl);
+            AppendValue(builder, nameof(programInfo.IsMovie), programInfo.IsMovie);
+            AppendValue(builder, nameof(programInfo.IsSports), programInfo.IsSports);
+            AppendValue(builder, nameof(programInfo.IsSeries), programInfo.IsSeries);
+            AppendValue(builder, nameof(programInfo.IsLive), programInfo.IsLive);
+            AppendValue(builder, nameof(programInfo.IsNews), programInfo.IsNews);
+            AppendValue(builder, nameof(programInfo.IsKids), programInfo.IsKids);
+            AppendValue(builder, nameof(programInfo.IsPremiere), programInfo.IsPremiere);
+            AppendValue(builder, nameof(programInfo.ProductionYear), programInfo.ProductionYear);
+            AppendValue(builder, nameof(programInfo.SeriesId), programInfo.SeriesId);
+            AppendValue(builder, nameof(programInfo.ShowId), programInfo.ShowId);
+            AppendValue(builder, nameof(programInfo.SeasonNumber), programInfo.SeasonNumber);
+            AppendValue(builder, nameof(programInfo.EpisodeNumber), programInfo.EpisodeNumber);
+            AppendDictionary(builder, nameof(programInfo.ProviderIds), programInfo.ProviderIds);
+            AppendDictionary(builder, nameof(programInfo.SeriesProviderIds), programInfo.SeriesProviderIds);
+
+            var hash = SHA256.HashData(Encoding.UTF8.GetBytes(builder.ToString()));
+            etag = Prefix + Convert.ToHexString(hash);
+            reason = null;
+            return true;
+        }
+
+        private static void AppendValue(StringBuilder builder, string name, string? value)
+        {
+            builder.Append(name).Append('|');
+            if (value is null)
+            {
+                builder.Append('N').Append("|0|");
+            }
+            else
+            {
+                builder.Append('S')
+                    .Append('|')
+                    .Append(value.Length.ToString(CultureInfo.InvariantCulture))
+                    .Append('|')
+                    .Append(value);
+            }
+
+            builder.Append('\n');
+        }
+
+        private static void AppendValue(StringBuilder builder, string name, DateTime value)
+            => AppendValue(builder, name, FormatDateTime(value));
+
+        private static void AppendValue(StringBuilder builder, string name, DateTime? value)
+            => AppendValue(builder, name, value.HasValue ? FormatDateTime(value.Value) : null);
+
+        // Treat Unspecified as UTC so the etag does not vary with the server's local timezone.
+        private static string FormatDateTime(DateTime value)
+        {
+            var utc = value.Kind switch
+            {
+                DateTimeKind.Utc => value,
+                DateTimeKind.Unspecified => DateTime.SpecifyKind(value, DateTimeKind.Utc),
+                _ => value.ToUniversalTime(),
+            };
+
+            return utc.ToString("O", CultureInfo.InvariantCulture);
+        }
+
+        private static void AppendValue(StringBuilder builder, string name, bool value)
+            => AppendValue(builder, name, value ? "true" : "false");
+
+        private static void AppendValue(StringBuilder builder, string name, bool? value)
+            => AppendValue(builder, name, value switch { true => "true", false => "false", null => null });
+
+        private static void AppendValue(StringBuilder builder, string name, int? value)
+            => AppendValue(builder, name, value?.ToString(CultureInfo.InvariantCulture));
+
+        private static void AppendValue(StringBuilder builder, string name, float? value)
+            => AppendValue(builder, name, value?.ToString("R", CultureInfo.InvariantCulture));
+
+        private static void AppendList(StringBuilder builder, string name, IReadOnlyList<string> values)
+        {
+            AppendValue(builder, name + ".Count", values.Count.ToString(CultureInfo.InvariantCulture));
+            for (var i = 0; i < values.Count; i++)
+            {
+                AppendValue(builder, $"{name}[{i}]", values[i]);
+            }
+        }
+
+        private static void AppendDictionary(StringBuilder builder, string name, IReadOnlyDictionary<string, string?> values)
+        {
+            AppendValue(builder, name + ".Count", values.Count.ToString(CultureInfo.InvariantCulture));
+            if (values.Count == 0)
+            {
+                return;
+            }
+
+            var index = 0;
+            foreach (var (key, value) in values
+                .OrderBy(i => i.Key, StringComparer.OrdinalIgnoreCase)
+                .ThenBy(i => i.Key, StringComparer.Ordinal))
+            {
+                AppendValue(builder, $"{name}[{index}].Key", key);
+                AppendValue(builder, $"{name}[{index}].Value", value);
+                index++;
+            }
+        }
+    }
+}