Fix up USFM pretranslations for Parallel corpus (#529)

* Fix up USFM pretranslations for Parallel corpus

* Make 'use first source' consistent across preprocessing & add check

* remove FIXME's that are no longer needed.

---------

Co-authored-by: Enkidu93 <lowryec17@gcc.edu>

src/Machine/src/Serval.Machine.Shared/Services/PreprocessBuildJob.cs

@@ -139,12 +139,16 @@ row.Ref is not ScriptureRef sr
                     );
                 })
                 .ToArray();
-            ITextCorpus[] sourcePretranslateCorpora = sourceCorpora
+            ITextCorpus? sourcePretranslateCorpus = sourceCorpora
                 .Select(sc =>
                 {
                     ITextCorpus textCorpus = sc.TextCorpus;
                     if (sc.Corpus.PretranslateTextIds is not null)
-                        textCorpus = textCorpus.FilterTexts(sc.Corpus.PretranslateTextIds);
+                    {
+                        textCorpus = textCorpus.FilterTexts(
+                            sc.Corpus.PretranslateTextIds.Except(sc.Corpus.TrainOnTextIds ?? new())
+                        );
+                    }
                     return textCorpus.Where(row =>
                         row.Ref is not ScriptureRef sr
                         || sc.Corpus.PretranslateChapters is null
@@ -154,7 +158,8 @@ row.Ref is not ScriptureRef sr
                         )
                     );
                 })
-                .ToArray();
+                .ToArray()
+                .FirstOrDefault();
 
             (MonolingualCorpus Corpus, ITextCorpus TextCorpus)[] targetCorpora = corpus
                 .TargetCorpora.SelectMany(c => _corpusService.CreateTextCorpora(c.Files).Select(tc => (c, tc)))
@@ -254,11 +259,13 @@ void WriteRow(Utf8JsonWriter writer, string textId, IReadOnlyList<object> refs,
 
             ITextCorpus targetCorpus =
                 targetCorpora.Length > 0 ? targetCorpora[0].TextCorpus : new DictionaryTextCorpus();
-
-            foreach (Row row in AlignPretranslateCorpus(sourcePretranslateCorpora, targetCorpus))
+            if (sourcePretranslateCorpus != null)
             {
-                if (row.SourceSegment.Length > 0)
-                    WriteRow(pretranslateWriter, row.TextId, row.Refs, row.SourceSegment);
+                foreach (Row row in AlignPretranslateCorpus(sourcePretranslateCorpus, targetCorpus))
+                {
+                    if (row.SourceSegment.Length > 0 && (row.TargetSegment.Length == 0 || !targetCorpus.Any()))
+                        WriteRow(pretranslateWriter, row.TextId, row.Refs, row.SourceSegment);
+                }
             }
         }
 
@@ -415,14 +422,18 @@ IReadOnlyList<ITextCorpus> trgCorpora
         }
     }
 
-    private static IEnumerable<Row> AlignPretranslateCorpus(ITextCorpus[] srcCorpora, ITextCorpus trgCorpus)
+    private static IEnumerable<Row> AlignPretranslateCorpus(ITextCorpus srcCorpus, ITextCorpus trgCorpus)
     {
         int rowCount = 0;
         StringBuilder srcSegBuffer = new();
         StringBuilder trgSegBuffer = new();
         List<object> refs = [];
         string textId = "";
-        foreach (ParallelTextRow row in srcCorpora.SelectMany(sc => sc.AlignRows(trgCorpus, allSourceRows: true)))
+
+        srcCorpus = srcCorpus.Transform(CleanSegment);
+        trgCorpus = trgCorpus.Transform(CleanSegment);
+
+        foreach (ParallelTextRow row in srcCorpus.AlignRows(trgCorpus, allSourceRows: true))
         {
             if (!row.IsTargetRangeStart && row.IsTargetInRange)
             {

src/Machine/test/Serval.Machine.Shared.Tests/Services/PreprocessBuildJobTests.cs

@@ -76,7 +76,6 @@ public async Task RunAsync_PretranslateAll()
 
         await env.RunBuildJobAsync(corpus1);
 
-        // FIXME This should be 4, but the "don't pretranslate things trained on" logic is not implemented yet.
         Assert.That(await env.GetPretranslateCountAsync(), Is.EqualTo(2));
     }
 
@@ -190,8 +189,11 @@ public async Task RunAsync_MixedSource_Paratext()
             Assert.That(trgCount, Is.EqualTo(1));
             Assert.That(termCount, Is.EqualTo(0));
         });
-        // FIXME - this should be 56 (or double check)
-        Assert.That(await env.GetPretranslateCountAsync(), Is.EqualTo(30));
+        Assert.That(
+            await env.GetPretranslateCountAsync(),
+            Is.EqualTo(13),
+            (await env.GetPretranslationsAsync())?.ToJsonString()
+        );
     }
 
     [Test]
@@ -210,8 +212,11 @@ public async Task RunAsync_MixedSource_Text()
             Assert.That(trgCount, Is.EqualTo(1));
             Assert.That(termCount, Is.EqualTo(0));
         });
-        // FIXME this should be 9.
-        Assert.That(await env.GetPretranslateCountAsync(), Is.EqualTo(5));
+        Assert.That(
+            await env.GetPretranslateCountAsync(),
+            Is.EqualTo(2),
+            (await env.GetPretranslationsAsync())?.ToJsonString()
+        );
     }
 
     [Test]
@@ -474,8 +479,7 @@ await env.GetTargetExtractAsync(),
         });
         JsonArray? pretranslations = await env.GetPretranslationsAsync();
         Assert.That(pretranslations, Is.Not.Null);
-        // FIXME this should be 37.
-        Assert.That(pretranslations!.Count, Is.EqualTo(24), pretranslations.ToJsonString());
+        Assert.That(pretranslations!.Count, Is.EqualTo(7), pretranslations.ToJsonString());
         Assert.That(
             pretranslations[2]!["translation"]!.ToString(),
             Is.EqualTo("Source one, chapter twelve, verse one.")

src/Serval/src/Serval.Translation/Controllers/TranslationEnginesController.cs

@@ -1372,6 +1372,24 @@ private static Build Map(Engine engine, TranslationBuildConfigDto source)
                         $"The parallel corpus {pcc.ParallelCorpusId} is not valid: This parallel corpus does not exist for engine {engine.Id}."
                     );
                 }
+                if (
+                    pcc.SourceFilters != null
+                    && pcc.SourceFilters.Count > 0
+                    && (
+                        pcc.SourceFilters.Select(sf => sf.CorpusId).Distinct().Count() > 1
+                        || pcc.SourceFilters[0].CorpusId
+                            != engine
+                                .ParallelCorpora.Where(pc => pc.Id == pcc.ParallelCorpusId)
+                                .First()
+                                .SourceCorpora[0]
+                                .Id
+                    )
+                )
+                {
+                    throw new InvalidOperationException(
+                        $"Only the first source corpus in a parallel corpus may be filtered for pretranslation."
+                    );
+                }
                 pretranslateCorpora.Add(
                     new PretranslateCorpus
                     {

src/Serval/src/Serval.Translation/Services/PretranslationService.cs

@@ -41,11 +41,24 @@ public async Task<string> GetUsfmAsync(
     {
         Engine? engine = await _engines.GetAsync(engineId, cancellationToken);
         Corpus? corpus = engine?.Corpora.SingleOrDefault(c => c.Id == corpusId);
-        if (corpus is null)
-            throw new EntityNotFoundException($"Could not find the Corpus '{corpusId}' in Engine '{engineId}'.");
+        ParallelCorpus? parallelCorpus = engine?.ParallelCorpora.SingleOrDefault(c => c.Id == corpusId);
 
-        CorpusFile sourceFile = corpus.SourceFiles[0];
-        CorpusFile targetFile = corpus.TargetFiles[0];
+        CorpusFile sourceFile;
+        CorpusFile targetFile;
+        if (corpus is not null)
+        {
+            sourceFile = corpus.SourceFiles[0];
+            targetFile = corpus.TargetFiles[0];
+        }
+        else if (parallelCorpus is not null)
+        {
+            sourceFile = parallelCorpus.SourceCorpora[0].Files[0];
+            targetFile = parallelCorpus.TargetCorpora[0].Files[0];
+        }
+        else
+        {
+            throw new EntityNotFoundException($"Could not find the Corpus '{corpusId}' in Engine '{engineId}'.");
+        }
         if (sourceFile.Format is not FileFormat.Paratext || targetFile.Format is not FileFormat.Paratext)
             throw new InvalidOperationException("USFM format is not valid for non-Scripture corpora.");