fix(streaming): missing HLS segments in edge requests (#10)

Reviewed-on: https://gitea.vodsystem.ddns.net/dylan/vod-system/pulls/10

src/test/java/com/ddf/vodsystem/services/media/StreamActionsServiceTest.java

@@ -1,5 +1,6 @@
 package com.ddf.vodsystem.services.media;
 
+import com.ddf.vodsystem.dto.ClipOptions;
 import com.ddf.vodsystem.dto.CommandOutput;
 import com.ddf.vodsystem.dto.ProgressTracker;
 import org.junit.jupiter.api.BeforeEach;
@@ -17,6 +18,7 @@ import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.time.Instant;
 import java.util.List;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -31,6 +33,9 @@ class StreamActionsServiceTest {
     @Mock
     private CommandRunner commandRunner;
 
+    @Mock
+    private MetadataService metadataService;
+
     private StreamActionsService service;
 
     @TempDir
@@ -38,155 +43,163 @@ class StreamActionsServiceTest {
 
     @BeforeEach
     void setUp() {
-        service = new StreamActionsService(commandRunner);
+        service = new StreamActionsService(commandRunner, metadataService);
     }
 
     private void createSegment(String name) throws IOException {
         Files.createFile(tempDir.resolve(name));
     }
 
+    /** Stubs the (async) metadata probe so {@code segments.getFirst()} reports {@code seconds}. */
+    private void stubHeadDuration(float seconds) {
+        ClipOptions meta = new ClipOptions();
+        meta.setDuration(seconds);
+        when(metadataService.getVideoMetadata(any())).thenReturn(CompletableFuture.completedFuture(meta));
+    }
+
+    /**
+     * Stubs the two-arg {@link CommandRunner#run} so the head re-encode pass
+     * actually writes a non-empty file at its output path — {@code encodeHead}
+     * verifies its output exists and is non-empty before continuing. The concat
+     * pass (no {@code mpegts} muxer) is left untouched. Returns {@code output}
+     * for both invocations.
+     */
+    private void stubRunnerProducingHead(CommandOutput output) throws IOException, InterruptedException {
+        when(commandRunner.run(anyList(), any())).thenAnswer(inv -> {
+            List<String> cmd = inv.getArgument(0);
+            if (cmd.contains("mpegts")) {
+                Files.writeString(Path.of(cmd.getLast()), "x");
+            }
+            return output;
+        });
+    }
+
     // ---------------------------------------------------------------
-    // getSegmentsInRange: missing / invalid directories
+    // selectSegments: missing / invalid directories
     // ---------------------------------------------------------------
 
     @Test
-    void getSegmentsInRange_directoryDoesNotExist_throwsIOException() {
+    void selectSegments_directoryDoesNotExist_throwsIOException() {
         Path missing = tempDir.resolve("does-not-exist");
 
-        assertThatThrownBy(() -> service.getSegmentsInRange(missing, Instant.EPOCH, Instant.now()))
+        assertThatThrownBy(() -> service.selectSegments(missing, Instant.EPOCH, Instant.now()))
                 .isInstanceOf(NoSuchFileException.class);
     }
 
     @Test
-    void getSegmentsInRange_pathIsAFileNotADirectory_throwsIOException() throws IOException {
+    void selectSegments_pathIsAFileNotADirectory_throwsIOException() throws IOException {
         Path file = tempDir.resolve("not-a-directory.txt");
         Files.createFile(file);
 
-        assertThatThrownBy(() -> service.getSegmentsInRange(file, Instant.EPOCH, Instant.now()))
+        assertThatThrownBy(() -> service.selectSegments(file, Instant.EPOCH, Instant.now()))
                 .isInstanceOf(IOException.class);
     }
 
-    @Test
-    void getSegmentsInRange_emptyDirectory_returnsEmptyList() throws IOException {
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(100_000));
-
-        assertThat(result).isEmpty();
-    }
-
     // ---------------------------------------------------------------
-    // getSegmentsInRange: filename filtering
+    // selectSegments: filename filtering
     // ---------------------------------------------------------------
 
     @Test
-    void getSegmentsInRange_ignoresFilesNotEndingInTs() throws IOException {
+    void selectSegments_ignoresFilesNotEndingInTs() throws IOException {
         createSegment("1.ts");
         createSegment("playlist.m3u8");
         createSegment("1.ts.tmp");
         createSegment("readme.txt");
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5000)).segments();
 
         assertThat(result).extracting(p -> p.getFileName().toString()).containsExactly("1.ts");
     }
 
     @Test
-    void getSegmentsInRange_directoryNamedLikeASegment_isNotIncluded() throws IOException {
+    void selectSegments_directoryNamedLikeASegment_isNotIncluded() throws IOException {
         Files.createDirectory(tempDir.resolve("5.ts"));
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000));
-
-        assertThat(result).isEmpty();
+        // the directory is the only ".ts" entry; excluding it leaves nothing to select
+        assertThatThrownBy(() ->
+                service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
+                .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
-    void getSegmentsInRange_malformedNonNumericFilename_throwsNumberFormatException() throws IOException {
+    void selectSegments_malformedNonNumericFilename_throwsNumberFormatException() throws IOException {
         // A real HLS fragment name is always numeric. A corrupted or partially-written
         // file (e.g. "index.ts") crashes the whole listing instead of just being skipped.
         createSegment("index.ts");
 
         assertThatThrownBy(() ->
-                service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
+                service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
                 .isInstanceOf(NumberFormatException.class);
     }
 
     @Test
-    void getSegmentsInRange_emptyFilenameBeforeExtension_throwsNumberFormatException() throws IOException {
+    void selectSegments_emptyFilenameBeforeExtension_throwsNumberFormatException() throws IOException {
         createSegment(".ts");
 
         assertThatThrownBy(() ->
-                service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
+                service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
                 .isInstanceOf(NumberFormatException.class);
     }
 
     // ---------------------------------------------------------------
-    // getSegmentsInRange: range-boundary arithmetic
+    // selectSegments: range-boundary arithmetic
     // ---------------------------------------------------------------
 
     @Test
-    void getSegmentsInRange_segmentEndsExactlyAtRangeStart_isExcluded() throws IOException {
-        // "0.ts" spans [0, 3000)ms. A request starting exactly at 3000ms should not
-        // pull in a segment that ended the instant before.
+    void selectSegments_segmentEndsExactlyAtRangeStart_isExcluded() throws IOException {
         createSegment("0.ts");
+        createSegment("3.ts");
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(3000), Instant.ofEpochMilli(10_000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(3000), Instant.ofEpochMilli(10_000)).segments();
 
-        assertThat(result).isEmpty();
+        assertThat(result).extracting(p -> p.getFileName().toString())
+                .containsExactly("3.ts");
     }
 
     @Test
-    void getSegmentsInRange_segmentOverlapsRangeStartByOneMs_isIncluded() throws IOException {
+    void selectSegments_segmentOverlapsRangeStartByOneMs_isIncluded() throws IOException {
         createSegment("0.ts"); // spans [0, 3000)
+        stubHeadDuration(3f);   // start 2999ms trims into 0.ts, so its duration is probed
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(2999), Instant.ofEpochMilli(10_000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(2999), Instant.ofEpochMilli(10_000)).segments();
 
         assertThat(result).hasSize(1);
     }
 
     @Test
-    void getSegmentsInRange_segmentStartsExactlyAtRangeEnd_isExcluded() throws IOException {
+    void selectSegments_segmentStartsExactlyAtRangeEnd_isExcluded() throws IOException {
         createSegment("5.ts"); // starts at 5000ms
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5000));
-
-        assertThat(result).isEmpty();
+        assertThatThrownBy(() ->
+                service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5000)))
+                .isInstanceOf(IllegalArgumentException.class);
     }
 
     @Test
-    void getSegmentsInRange_segmentStartsOneMsBeforeRangeEnd_isIncluded() throws IOException {
+    void selectSegments_segmentStartsOneMsBeforeRangeEnd_isIncluded() throws IOException {
         createSegment("5.ts"); // starts at 5000ms
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5001));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(5001)).segments();
 
         assertThat(result).hasSize(1);
     }
 
     @Test
-    void getSegmentsInRange_startAfterEnd_throwsIllegalArgument() throws IOException {
+    void selectSegments_startAfterEnd_throwsIllegalArgument() throws IOException {
         createSegment("10.ts");
 
         assertThatThrownBy(() ->
-                service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(20_000), Instant.ofEpochMilli(10_000)))
+                service.selectSegments(tempDir, Instant.ofEpochMilli(20_000), Instant.ofEpochMilli(10_000)))
                 .isInstanceOf(IllegalArgumentException.class);
-
     }
 
     @Test
-    void getSegmentsInRange_segmentsWhollyOutsideRange_areExcluded() throws IOException {
-        createSegment("0.ts");   // [0, 3000)
-        createSegment("100.ts"); // [100000, 103000)
-
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(50_000), Instant.ofEpochMilli(60_000));
-
-        assertThat(result).isEmpty();
-    }
-
-    @Test
-    void getSegmentsInRange_segmentsOutOfOrder_returnedInOrder() throws IOException {
+    void selectSegments_segmentsOutOfOrder_returnedInOrder() throws IOException {
         createSegment("20.ts");
         createSegment("10.ts");
         createSegment("0.ts");
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(25_000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(25_000)).segments();
 
         assertThat(result)
                 .extracting(p -> p.getFileName().toString())
@@ -194,31 +207,98 @@ class StreamActionsServiceTest {
     }
 
     @Test
-    void getSegmentsInRange_mixOfOverlappingAndNonOverlappingSegments_returnsOnlyOverlapping() throws IOException {
+    void selectSegments_mixOfOverlappingAndNonOverlappingSegments_returnsOnlyOverlapping() throws IOException {
         createSegment("0.ts"); // [0, 3000)
         createSegment("3.ts"); // [3000, 6000)
         createSegment("6.ts"); // [6000, 9000)
         createSegment("9.ts"); // [9000, 12000)
+        stubHeadDuration(3f);   // start 4000ms trims into 3.ts, so its duration is probed
 
-
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(4000), Instant.ofEpochMilli(8000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(4000), Instant.ofEpochMilli(8000)).segments();
 
         assertThat(result).extracting(p -> p.getFileName().toString())
                 .containsExactly("3.ts", "6.ts");
     }
 
     @Test
-    void getSegmentsInRange_resultsAreSortedByTimestampRegardlessOfDirectoryOrder() throws IOException {
+    void selectSegments_resultsAreSortedByTimestampRegardlessOfDirectoryOrder() throws IOException {
         createSegment("30.ts");
         createSegment("10.ts");
         createSegment("20.ts");
 
-        List<Path> result = service.getSegmentsInRange(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(100_000));
+        var result = service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(100_000)).segments();
 
         assertThat(result).extracting(p -> p.getFileName().toString())
                 .containsExactly("10.ts", "20.ts", "30.ts");
     }
 
+    // ---------------------------------------------------------------
+    // selectSegments: head selection and trim-offset
+    // ---------------------------------------------------------------
+
+    @Test
+    void selectSegments_startWithinFirstSegment_keepsItAndComputesOffset() throws IOException {
+        createSegment("30.ts");
+        createSegment("33.ts");
+        stubHeadDuration(3f); // 30.ts spans [30s, 33s)
+
+        var selection = service.selectSegments(tempDir, Instant.ofEpochMilli(31_500), Instant.ofEpochMilli(40_000));
+
+        assertThat(selection.segments()).extracting(p -> p.getFileName().toString())
+                .containsExactly("30.ts", "33.ts");
+        assertThat(selection.trimOffset()).isEqualTo(1.5f);
+        // effective start equals the requested 31.5s, so duration runs to endTime: 40 - 31.5
+        assertThat(selection.duration()).isEqualTo(8.5f);
+    }
+
+    @Test
+    void selectSegments_startInGapAfterFirstSegment_dropsItAndStartsAtNext() throws IOException {
+        createSegment("30.ts");
+        // user stops streaming; a gap follows 30.ts
+        createSegment("100.ts");
+        createSegment("110.ts");
+        stubHeadDuration(3f); // 30.ts only holds [30s, 33s); requested start 70s is past it
+
+        var selection = service.selectSegments(tempDir, Instant.ofEpochMilli(70_000), Instant.ofEpochMilli(111_000));
+
+        assertThat(selection.segments()).extracting(p -> p.getFileName().toString())
+                .containsExactly("100.ts", "110.ts");
+        assertThat(selection.trimOffset()).isZero();
+        // the dropped head shifts the effective start to 100s, so the duration
+        // shrinks to end at endTime (111 - 100 = 11s) instead of the 41s the
+        // original 70s->111s window would have implied
+        assertThat(selection.duration()).isEqualTo(11f);
+    }
+
+    @Test
+    void selectSegments_startPastOnlySegment_throwsIllegalArgument() throws IOException {
+        createSegment("0.ts");
+        stubHeadDuration(3f); // 0.ts holds [0s, 3s); requested start 50s has no footage
+
+        assertThatThrownBy(() ->
+                service.selectSegments(tempDir, Instant.ofEpochMilli(50_000), Instant.ofEpochMilli(60_000)))
+                .isInstanceOf(IllegalArgumentException.class);
+    }
+
+    @Test
+    void selectSegments_noSegmentsInRange_throwsIllegalArgument() {
+        assertThatThrownBy(() ->
+                service.selectSegments(tempDir, Instant.ofEpochMilli(0), Instant.ofEpochMilli(10_000)))
+                .isInstanceOf(IllegalArgumentException.class);
+    }
+
+    @Test
+    void selectSegments_probeFailure_surfacesAsIOException() throws IOException {
+        createSegment("30.ts");
+        createSegment("100.ts");
+        when(metadataService.getVideoMetadata(any()))
+                .thenReturn(CompletableFuture.failedFuture(new IOException("ffprobe boom")));
+
+        assertThatThrownBy(() ->
+                service.selectSegments(tempDir, Instant.ofEpochMilli(70_000), Instant.ofEpochMilli(111_000)))
+                .isInstanceOf(IOException.class);
+    }
+
     // ---------------------------------------------------------------
     // parseTimestampMs: unit-based conversion
     // ---------------------------------------------------------------
@@ -275,24 +355,55 @@ class StreamActionsServiceTest {
         ProgressTracker progress = new ProgressTracker();
         CommandOutput commandOutput = new CommandOutput();
 
-        when(commandRunner.run(anyList(), any())).thenReturn(commandOutput);
+        stubRunnerProducingHead(commandOutput);
 
-        var future = service.saveSection(List.of(segmentA, segmentB), 5.0f, 12.0f, output, progress);
+        var future = service.saveSection(
+                new StreamActionsService.SegmentSelection(List.of(segmentA, segmentB), 5.0f, 12.0f), output, progress);
 
         assertThat(future.get()).isSameAs(commandOutput);
         assertThat(progress.isComplete()).isTrue();
 
+        // With a non-zero trim offset saveSection issues two ffmpeg passes: the
+        // head re-encode (trims the first segment via -ss) followed by the
+        // concat-demuxer stream copy (-f concat / -t / -c copy).
         @SuppressWarnings("unchecked")
         ArgumentCaptor<List<String>> captor = ArgumentCaptor.forClass(List.class);
-        Mockito.verify(commandRunner).run(captor.capture(), any());
+        Mockito.verify(commandRunner, Mockito.times(2)).run(captor.capture(), any());
+        List<String> headCommand = captor.getAllValues().get(0);
+        List<String> concatCommand = captor.getAllValues().get(1);
+
+        assertThat(headCommand).containsSequence("-ss", "5.0");
+        assertThat(concatCommand).containsSequence("-f", "concat");
+        assertThat(concatCommand).containsSequence("-t", "12.0");
+        assertThat(concatCommand).containsSequence("-c", "copy");
+        assertThat(concatCommand).endsWith(output.toAbsolutePath().toString());
+    }
+
+    @Test
+    void saveSection_zeroTrimOffset_skipsHeadReencodeAndRunsSingleConcatPass() throws Exception {
+        Path output = Path.of("/tmp/out/clip.mp4");
+        ProgressTracker progress = new ProgressTracker();
+        CommandOutput commandOutput = new CommandOutput();
+
+        when(commandRunner.run(anyList(), any())).thenReturn(commandOutput);
+
+        var future = service.saveSection(
+                new StreamActionsService.SegmentSelection(
+                        List.of(Path.of("/tmp/a.ts"), Path.of("/tmp/b.ts")), 0f, 10f), output, progress);
+
+        assertThat(future.get()).isSameAs(commandOutput);
+        assertThat(progress.isComplete()).isTrue();
+
+        // trimOffset 0 means the first segment already starts at the requested point:
+        // no head re-encode pass, just a single concat-demuxer copy (no -ss).
+        @SuppressWarnings("unchecked")
+        ArgumentCaptor<List<String>> captor = ArgumentCaptor.forClass(List.class);
+        Mockito.verify(commandRunner, Mockito.times(1)).run(captor.capture(), any());
         List<String> command = captor.getValue();
 
-        assertThat(command).containsSequence("-i",
-                "concat:" + segmentA.toAbsolutePath() + "|" + segmentB.toAbsolutePath());
-        assertThat(command).containsSequence("-ss", "5.0");
-        assertThat(command).containsSequence("-t", "12.0");
-        assertThat(command).containsSequence("-c", "copy");
-        assertThat(command).endsWith(output.toAbsolutePath().toString());
+        assertThat(command).containsSequence("-f", "concat");
+        assertThat(command).containsSequence("-t", "10.0");
+        assertThat(command).doesNotContain("-ss");
     }
 
     @Test
@@ -300,9 +411,12 @@ class StreamActionsServiceTest {
         Path output = Path.of("/tmp/out/clip.mp4");
         ProgressTracker progress = new ProgressTracker();
 
+        // With a non-zero trim offset the head re-encode is the first ffmpeg pass;
+        // its failure must surface.
         when(commandRunner.run(anyList(), any())).thenThrow(new IOException("ffmpeg boom"));
 
-        var future = service.saveSection(List.of(Path.of("/tmp/a.ts")), 0f, 10f, output, progress);
+        var future = service.saveSection(
+                new StreamActionsService.SegmentSelection(List.of(Path.of("/tmp/a.ts")), 2f, 10f), output, progress);
 
         assertThatThrownBy(future::get)
                 .isInstanceOf(ExecutionException.class)
@@ -311,15 +425,16 @@ class StreamActionsServiceTest {
     }
 
     @Test
-    void saveSection_emptySegmentList_completesExceptionallyWithIllegalStateException() {
+    void saveSection_emptySegmentList_completesExceptionallyWithIllegalArgumentException() {
         Path output = Path.of("/tmp/out/clip.mp4");
         ProgressTracker progress = new ProgressTracker();
 
-        var future = service.saveSection(List.of(), 0f, 10f, output, progress);
+        var future = service.saveSection(
+                new StreamActionsService.SegmentSelection(List.of(), 0f, 10f), output, progress);
 
         assertThatThrownBy(future::get)
                 .isInstanceOf(ExecutionException.class)
-                .hasCauseInstanceOf(IllegalStateException.class);
+                .hasCauseInstanceOf(IllegalArgumentException.class);
         assertThat(progress.isComplete()).isFalse();
     }
 
@@ -327,7 +442,10 @@ class StreamActionsServiceTest {
     void saveSection_nullOutputFile_completesExceptionally() {
         ProgressTracker progress = new ProgressTracker();
 
-        var future = service.saveSection(List.of(Path.of("/tmp/a.ts")), 0f, 10f, null, progress);
+        // trimOffset 0 skips the head pass; building the concat command dereferences
+        // the null output path, so no ffmpeg pass ever runs.
+        var future = service.saveSection(
+                new StreamActionsService.SegmentSelection(List.of(Path.of("/tmp/a.ts")), 0f, 10f), null, progress);
 
         assertThatThrownBy(future::get)
                 .isInstanceOf(ExecutionException.class)