Handle scheduled clipping failures

docs/input-folder-scheduler-plan.md

@@ -27,7 +27,7 @@ Note: the local machine's filesystem root is read-only in this workspace, so abs
 7. [x] Add invalid-file handling that logs the reason and moves files to rejected storage.
 8. [x] Add FFmpeg clipping into `/output/clips/<video-name>/` using 8-second MP4/H.264/AAC segments.
 9. [x] Add success handling that moves processed source files to processed storage.
-10. [ ] Add failure handling for FFmpeg or filesystem errors.
+10. [x] Add failure handling for FFmpeg or filesystem errors.
 11. [ ] Add unit tests for ordering, invalid-file handling, repeat prevention, and state transitions.
 12. [ ] Add optional FFmpeg integration test for a short fixture.
 13. [ ] Add local profile or documented runtime config for enabling the scheduler.

src/main/java/org/example/videoclips/folder/FolderVideoScanScheduler.java

@@ -48,9 +48,7 @@ public class FolderVideoScanScheduler {
         try {
             findNextCandidate().ifPresentOrElse(
                     candidate -> {
-                        Path workingFile = moveToWorking(candidate);
+                        processCandidate(candidate);
-                        log.info("Claimed folder video candidate for processing: {}", workingFile.getFileName());
-                        validateCandidate(workingFile);
                     },
                     () -> log.debug("No folder video candidate found in {}", properties.getInputDirectory())
             );
@@ -59,6 +57,42 @@ public class FolderVideoScanScheduler {
         }
     }
 
+    private void processCandidate(Path candidate) {
+        Path activeFile = candidate;
+        try {
+            activeFile = moveToWorking(candidate);
+            log.info("Claimed folder video candidate for processing: {}", activeFile.getFileName());
+            validateCandidate(activeFile);
+        } catch (RuntimeException ex) {
+            handleFailure(activeFile, ex);
+        }
+    }
+
+    private void handleFailure(Path activeFile, RuntimeException failure) {
+        log.error("Folder video processing failed for {} ({})", activeFile.getFileName(),
+                failure.getClass().getSimpleName());
+        try {
+            Path rejectedFile = moveToDirectory(activeFile, Path.of(properties.getRejectedDirectory()));
+            log.warn("Moved failed folder video source to rejected storage: {}", rejectedFile.getFileName());
+        } catch (RuntimeException rejectionFailure) {
+            markFailed(activeFile);
+        }
+    }
+
+    void markFailed(Path source) {
+        Path marker = source.resolveSibling(source.getFileName() + ".failed");
+        if (Files.exists(marker)) {
+            log.error("Unable to mark failed folder video source because marker already exists: {}", marker.getFileName());
+            return;
+        }
+        try {
+            Files.move(source, marker, StandardCopyOption.ATOMIC_MOVE);
+            log.warn("Marked folder video source as failed: {}", marker.getFileName());
+        } catch (IOException ex) {
+            log.error("Unable to quarantine or mark failed folder video source: {}", source.getFileName());
+        }
+    }
+
     private void validateCandidate(Path workingFile) {
         FolderVideoValidator.ValidationResult result = validator.validate(workingFile);
         if (result.valid()) {
@@ -116,7 +150,8 @@ public class FolderVideoScanScheduler {
         return !fileName.startsWith(".")
                 && !fileName.endsWith(".tmp")
                 && !fileName.endsWith(".part")
-                && !fileName.endsWith(".download");
+                && !fileName.endsWith(".download")
+                && !fileName.endsWith(".failed");
     }
 
     private Comparator<Path> candidateComparator() {

src/test/java/org/example/videoclips/folder/FolderVideoScanSchedulerTest.java

@@ -44,6 +44,7 @@ class FolderVideoScanSchedulerTest {
         Files.writeString(tempDir.resolve("upload.mp4.tmp"), "video");
         Files.writeString(tempDir.resolve("upload.mp4.part"), "video");
         Files.writeString(tempDir.resolve("upload.mp4.download"), "video");
+        Files.writeString(tempDir.resolve("upload.mp4.failed"), "video");
         Files.writeString(tempDir.resolve("valid.mp4"), "video");
 
         Optional<Path> candidate = scheduler(tempDir).findNextCandidate();
@@ -143,8 +144,9 @@ class FolderVideoScanSchedulerTest {
         FolderVideoValidator validator = mock(FolderVideoValidator.class);
         when(validator.validate(any())).thenReturn(FolderVideoValidator.ValidationResult.invalid("invalid"));
 
-        assertThrows(IllegalStateException.class, () -> scheduler(tempDir, validator).scan());
+        scheduler(tempDir, validator).scan();
-        assertTrue(Files.exists(tempDir.resolve("working/invalid.mp4")));
+
+        assertTrue(Files.exists(tempDir.resolve("working/invalid.mp4.failed")));
     }
 
     @Test
@@ -153,10 +155,58 @@ class FolderVideoScanSchedulerTest {
         Files.createDirectory(tempDir.resolve("processed"));
         Files.writeString(tempDir.resolve("processed/1.mp4"), "existing video");
 
-        assertThrows(IllegalStateException.class, () -> scheduler(tempDir).scan());
+        scheduler(tempDir).scan();
 
         assertEquals("existing video", Files.readString(tempDir.resolve("processed/1.mp4")));
-        assertEquals("new video", Files.readString(tempDir.resolve("working/1.mp4")));
+        assertEquals("new video", Files.readString(tempDir.resolve("rejected/1.mp4")));
+    }
+
+    @Test
+    void quarantinesSourceWhenClipGenerationFails() throws Exception {
+        Files.writeString(tempDir.resolve("broken.mp4"), "video");
+        FolderFfmpegClipper clipper = mock(FolderFfmpegClipper.class);
+        when(clipper.clip(any())).thenThrow(new IllegalStateException("ffmpeg failed"));
+
+        scheduler(tempDir, acceptedValidator(), clipper).scan();
+
+        assertEquals("video", Files.readString(tempDir.resolve("rejected/broken.mp4")));
+        assertFalse(Files.exists(tempDir.resolve("working/broken.mp4")));
+    }
+
+    @Test
+    void quarantinesInputWhenClaimingFails() throws Exception {
+        Files.writeString(tempDir.resolve("broken.mp4"), "video");
+        Files.createDirectory(tempDir.resolve("working"));
+        Files.writeString(tempDir.resolve("working/broken.mp4"), "collision");
+
+        scheduler(tempDir).scan();
+
+        assertEquals("video", Files.readString(tempDir.resolve("rejected/broken.mp4")));
+    }
+
+    @Test
+    void ignoresFailureWhenActiveSourceHasAlreadyDisappeared() throws Exception {
+        Files.writeString(tempDir.resolve("vanished.mp4"), "video");
+        FolderVideoValidator validator = mock(FolderVideoValidator.class);
+        when(validator.validate(any())).thenAnswer(invocation -> {
+            Files.delete(invocation.getArgument(0));
+            throw new IllegalStateException("vanished");
+        });
+
+        scheduler(tempDir, validator).scan();
+
+        assertFalse(Files.exists(tempDir.resolve("working/vanished.mp4.failed")));
+    }
+
+    @Test
+    void doesNotOverwriteExistingFailureMarker() throws Exception {
+        Path source = Files.writeString(tempDir.resolve("video.mp4"), "source");
+        Files.writeString(tempDir.resolve("video.mp4.failed"), "marker");
+
+        scheduler(tempDir).markFailed(source);
+
+        assertEquals("source", Files.readString(source));
+        assertEquals("marker", Files.readString(tempDir.resolve("video.mp4.failed")));
     }
 
     @Test
@@ -169,9 +219,7 @@ class FolderVideoScanSchedulerTest {
     }
 
     private FolderVideoScanScheduler scheduler(Path inputDirectory) {
-        FolderVideoValidator validator = mock(FolderVideoValidator.class);
+        return scheduler(inputDirectory, acceptedValidator(), successfulClipper());
-        when(validator.validate(any())).thenReturn(FolderVideoValidator.ValidationResult.accepted());
-        return scheduler(inputDirectory, validator, successfulClipper());
     }
 
     private FolderVideoScanScheduler scheduler(Path inputDirectory, FolderVideoValidator validator) {
@@ -216,4 +264,10 @@ class FolderVideoScanSchedulerTest {
         when(clipper.clip(any())).thenReturn(new FolderFfmpegClipper.ClipResult(tempDir.resolve("output/1"), 1));
         return clipper;
     }
+
+    private FolderVideoValidator acceptedValidator() {
+        FolderVideoValidator validator = mock(FolderVideoValidator.class);
+        when(validator.validate(any())).thenReturn(FolderVideoValidator.ValidationResult.accepted());
+        return validator;
+    }
 }