feat: track theme file md5 hash (#185)

Jellyfin.Plugin.Themerr.Tests/TestThemerrManager.cs

@@ -60,6 +60,44 @@ private List<string> FixtureThemerrDbUrls()
         return youtubeUrls;
     }
 
+    [Fact]
+    [Trait("Category", "Unit")]
+    private void TestGetExistingThemerrDataValue()
+    {
+        string themerrDataPath;
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "dummy.json");
+
+        // ensure correct values are returned
+        Assert.Equal(
+            "dummy_value",
+            _themerrManager.GetExistingThemerrDataValue("dummy_key", themerrDataPath));
+        Assert.Equal(
+            "https://www.youtube.com/watch?v=E8nxMWr2sr4",
+            _themerrManager.GetExistingThemerrDataValue("youtube_theme_url", themerrDataPath));
+
+        // ensure null when the key does not exist
+        Assert.Null(_themerrManager.GetExistingThemerrDataValue("invalid_key", themerrDataPath));
+
+        // ensure null when the file does not exist
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "no_file.json");
+
+        Assert.Null(_themerrManager.GetExistingThemerrDataValue("any_key", themerrDataPath));
+
+        // test empty json file
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "empty.json");
+
+        Assert.Null(_themerrManager.GetExistingThemerrDataValue("any_key", themerrDataPath));
+    }
+
     [Fact]
     [Trait("Category", "Unit")]
     private void TestSaveMp3()
@@ -180,15 +218,80 @@ private void TestSaveMp3InvalidUrl()
 
     [Fact]
     [Trait("Category", "Unit")]
-    private void TestShouldSkipDownload()
+    private void TestContinueDownload()
     {
-        var themePath = Path.Combine(
-            "theme.mp3");
-        var themerrDataPath = Path.Combine(
-            "themerr_data.json");
-
-        var shouldSkipDownload = _themerrManager.ShouldSkipDownload(themePath, themerrDataPath);
-        Assert.False(shouldSkipDownload, "ShouldSkipDownload returned True");
+        string themePath;
+        string themerrDataPath;
+
+        // test when neither theme nor data file exists
+        themePath = Path.Combine(
+            "no_file.mp3");
+        themerrDataPath = Path.Combine(
+            "no_file.json");
+        Assert.True(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned False");
+
+        // test when theme does not exist and data file does
+        themePath = Path.Combine(
+            "no_file.mp3");
+
+        // copy the dummy.json to a secondary location
+        var ogFile = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "dummy.json");
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "dummy2.json");
+
+        // copy the dummy.json
+        File.Copy(ogFile, themerrDataPath);
+        Assert.True(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned False");
+        Assert.False(File.Exists(themerrDataPath), $"File {themerrDataPath} was not removed");
+
+        // test when theme file exists but data file does not
+        themePath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_stub.mp3");
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "no_file.json");
+        Assert.False(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned True");
+
+        // test when both theme and data file exist, but hash is empty in data file
+        themePath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_stub.mp3");
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "dummy.json");
+        Assert.True(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned False");
+
+        // test when both theme and data file exist, and md5 hashes match
+        themePath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_stub.mp3");
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_themerr_data.json");
+        Assert.True(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned False");
+
+        // test when both theme and data file exist, and md5 hashes do not match
+        themePath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_stub.mp3");
+        themerrDataPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "audio_themerr_data_user_overwritten.json");
+        Assert.False(_themerrManager.ContinueDownload(themePath, themerrDataPath), "ContinueDownload returned True");
     }
 
     [Fact]
@@ -273,11 +376,16 @@ private void TestSaveThemerrData()
         // set mock themerrDataPath using a random number
         var mockThemerrDataPath = $"themerr_{new Random().Next()}.json";
 
+        var stubVideoPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "video_stub.mp4");
+
         // loop over each themerrDbLink
         foreach (var youtubeThemeUrl in FixtureYoutubeUrls())
         {
             // save themerr data
-            var fileExists = _themerrManager.SaveThemerrData(mockThemerrDataPath, youtubeThemeUrl);
+            var fileExists = _themerrManager.SaveThemerrData(stubVideoPath, mockThemerrDataPath, youtubeThemeUrl);
             Assert.True(fileExists, $"SaveThemerrData did not return True for {youtubeThemeUrl}");
 
             // check if file exists
@@ -293,4 +401,27 @@ private void TestSaveThemerrData()
                 $"youtubeThemeUrl {youtubeThemeUrl} does not match savedYoutubeThemeUrl {savedYoutubeThemeUrl}");
         }
     }
+
+    [Fact]
+    [Trait("Category", "Unit")]
+    private void TestGetMd5Hash()
+    {
+        var stubVideoPath = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "video_stub.mp4");
+
+        var expectedMd5HashFile = Path.Combine(
+            Directory.GetCurrentDirectory(),
+            "data",
+            "video_stub.mp4.md5");
+
+        // get expected md5 hash out of file
+        var expectedMd5Hash = File.ReadAllText(expectedMd5HashFile).Trim();
+
+        // get actual md5 hash
+        var actualMd5Hash = _themerrManager.GetMd5Hash(stubVideoPath);
+
+        Assert.Equal(expectedMd5Hash, actualMd5Hash);
+    }
 }

Jellyfin.Plugin.Themerr.Tests/data/audio_themerr_data.json

@@ -0,0 +1,3 @@
+{
+  "theme_md5": "44c5eaa73e9b362911aaaf12a5609ab7"
+}

Jellyfin.Plugin.Themerr.Tests/data/audio_themerr_data_user_overwritten.json

@@ -0,0 +1,3 @@
+{
+  "theme_md5": "abcd"
+}

Jellyfin.Plugin.Themerr.Tests/data/dummy.json

@@ -0,0 +1,5 @@
+{
+  "downloaded_timestamp": "2023-12-12T04:07:41.7659077Z",
+  "youtube_theme_url": "https://www.youtube.com/watch?v=E8nxMWr2sr4",
+  "dummy_key": "dummy_value"
+}

Jellyfin.Plugin.Themerr.Tests/data/empty.json

@@ -0,0 +1 @@
+

Jellyfin.Plugin.Themerr/ThemerrManager.cs

@@ -42,20 +42,21 @@ public ThemerrManager(ILibraryManager libraryManager, ILogger<ThemerrManager> lo
         }
 
         /// <summary>
-        /// Get the existing youtube theme url from the themerr data file if it exists.
+        /// Get a value from the themerr data file if it exists.
         /// </summary>
+        /// <param name="key">The key to search for.</param>
         /// <param name="themerrDataPath">The path to the themerr data file.</param>
-        /// <returns>The existing YouTube theme url if it exists, empty string otherwise.</returns>
-        public static string GetExistingYoutubeThemeUrl(string themerrDataPath)
+        /// <returns>The value of the key if it exists, null otherwise.</returns>
+        public string GetExistingThemerrDataValue(string key, string themerrDataPath)
         {
             if (!System.IO.File.Exists(themerrDataPath))
             {
-                return string.Empty;
+                return null;
             }
 
             var jsonString = System.IO.File.ReadAllText(themerrDataPath);
             dynamic jsonData = JsonConvert.DeserializeObject(jsonString);
-            return jsonData?.youtube_theme_url;
+            return jsonData?[key];
         }
 
         /// <summary>
@@ -132,42 +133,83 @@ public void ProcessMovieTheme(Movie movie)
             var themePath = GetThemePath(movie);
             var themerrDataPath = GetThemerrDataPath(movie);
 
-            if (ShouldSkipDownload(themePath, themerrDataPath))
+            if (!ContinueDownload(themePath, themerrDataPath))
             {
                 return;
             }
 
-            var existingYoutubeThemeUrl = GetExistingYoutubeThemeUrl(themerrDataPath);
+            var existingYoutubeThemeUrl = GetExistingThemerrDataValue("youtube_theme_url", themerrDataPath);
 
             // get tmdb id
             var tmdbId = movie.GetProviderId(MetadataProvider.Tmdb);
 
             // create themerrdb url
-            var themerrDbLink = CreateThemerrDbLink(tmdbId);
+            var themerrDbUrl = CreateThemerrDbLink(tmdbId);
 
-            var youtubeThemeUrl = GetYoutubeThemeUrl(themerrDbLink, movieTitle);
+            var youtubeThemeUrl = GetYoutubeThemeUrl(themerrDbUrl, movieTitle);
 
             if (string.IsNullOrEmpty(youtubeThemeUrl) || youtubeThemeUrl == existingYoutubeThemeUrl)
             {
                 return;
             }
 
-            SaveMp3(themePath, youtubeThemeUrl);
-            SaveThemerrData(themerrDataPath, youtubeThemeUrl);
+            var successMp3 = SaveMp3(themePath, youtubeThemeUrl);
+            if (!successMp3)
+            {
+                return;
+            }
+
+            var successThemerrData = SaveThemerrData(themePath, themerrDataPath, youtubeThemeUrl);
+            if (!successThemerrData)
+            {
+                return;
+            }
+
             movie.RefreshMetadata(CancellationToken.None);
         }
 
         /// <summary>
         /// Check if the theme song should be downloaded.
         ///
-        /// If theme.mp3 exists and themerr.json doesn't exist, then skip to avoid overwriting user supplied themes.
+        /// Various checks are performed to determine if the theme song should be downloaded.
         /// </summary>
         /// <param name="themePath">The path to the theme song.</param>
         /// <param name="themerrDataPath">The path to the themerr data file.</param>
-        /// <returns>True if the theme song should NOT be downloaded, false otherwise.</returns>
-        public bool ShouldSkipDownload(string themePath, string themerrDataPath)
+        /// <returns>True to continue with downloaded, false otherwise.</returns>
+        public bool ContinueDownload(string themePath, string themerrDataPath)
         {
-            return System.IO.File.Exists(themePath) && !System.IO.File.Exists(themerrDataPath);
+            if (!System.IO.File.Exists(themePath) && !System.IO.File.Exists(themerrDataPath))
+            {
+                // neither file exists, so don't skip
+                return true;
+            }
+
+            if (!System.IO.File.Exists(themePath) && System.IO.File.Exists(themerrDataPath))
+            {
+                // the theme is missing, so delete the themerr data file
+                System.IO.File.Delete(themerrDataPath);
+                return true;
+            }
+
+            if (System.IO.File.Exists(themePath) && !System.IO.File.Exists(themerrDataPath))
+            {
+                // the theme is user supplied, so don't overwrite it
+                return false;
+            }
+
+            var existingThemeMd5 = GetExistingThemerrDataValue("theme_md5", themerrDataPath);
+
+            // if existing theme md5 is empty, don't skip
+            if (string.IsNullOrEmpty(existingThemeMd5))
+            {
+                return true;
+            }
+
+            // check if the theme hash matches what is in the themerr data file
+            var themeMd5 = GetMd5Hash(themePath);
+
+            // if hashes match, theme is supplied by themerr, otherwise it is user supplied
+            return themeMd5 == existingThemeMd5;
         }
 
         /// <summary>
@@ -226,15 +268,17 @@ public string GetYoutubeThemeUrl(string themerrDbUrl, string movieTitle)
         /// <summary>
         /// Save the themerr data file.
         /// </summary>
+        /// <param name="themePath">The path to the theme song.</param>
         /// <param name="themerrDataPath">The path to the themerr data file.</param>
         /// <param name="youtubeThemeUrl">The YouTube theme url.</param>
         /// <returns>True if the file was saved successfully, false otherwise.</returns>
-        public bool SaveThemerrData(string themerrDataPath, string youtubeThemeUrl)
+        public bool SaveThemerrData(string themePath, string themerrDataPath, string youtubeThemeUrl)
         {
             var success = false;
             var themerrData = new
             {
                 downloaded_timestamp = DateTime.UtcNow,
+                theme_md5 = GetMd5Hash(themePath),
                 youtube_theme_url = youtubeThemeUrl
             };
             try
@@ -250,6 +294,23 @@ public bool SaveThemerrData(string themerrDataPath, string youtubeThemeUrl)
             return success && WaitForFile(themerrDataPath, 10000);
         }
 
+        /// <summary>
+        /// Get the MD5 hash of a file.
+        /// </summary>
+        /// <param name="filePath">The file path.</param>
+        /// <returns>The MD5 hash of the file.</returns>
+        public string GetMd5Hash(string filePath)
+        {
+            using (var md5 = System.Security.Cryptography.MD5.Create())
+            {
+                using (var stream = System.IO.File.OpenRead(filePath))
+                {
+                    var hash = md5.ComputeHash(stream);
+                    return BitConverter.ToString(hash).Replace("-", string.Empty).ToLowerInvariant();
+                }
+            }
+        }
+
         /// <summary>
         /// Wait for file to exist on disk and is not locked by another process.
         /// </summary>