feat(stream): implement clipping functionality

pom.xml

@@ -81,6 +81,10 @@
 			<artifactId>google-api-client</artifactId>
 			<version>2.8.0</version>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-validation</artifactId>
+		</dependency>
 	</dependencies>
 
 	<build>

src/main/java/com/ddf/vodsystem/controllers/StreamController.java

@@ -1,7 +1,8 @@
 package com.ddf.vodsystem.controllers;
 
+import com.ddf.vodsystem.controllers.input.ClipSectionRequest;
 import com.ddf.vodsystem.dto.APIResponse;
-import com.ddf.vodsystem.dto.SaveSectionRequest;
+import com.ddf.vodsystem.controllers.input.SaveSectionRequest;
 import com.ddf.vodsystem.entities.Stream;
 import com.ddf.vodsystem.services.StreamService;
 import org.slf4j.Logger;
@@ -53,6 +54,13 @@ public class StreamController {
         return ResponseEntity.accepted().body(new APIResponse<>("success", "Section saved", null));
     }
 
+    @PostMapping("/clip")
+    public ResponseEntity<APIResponse<Void>> saveClip(
+            @RequestBody ClipSectionRequest request) throws IOException, InterruptedException {
+        streamService.clip(request.duration());
+        return ResponseEntity.accepted().body(new APIResponse<>("success", "Clip saved", null));
+    }
+
     @GetMapping("/history/{userId}")
     public ResponseEntity<APIResponse<List<Stream>>> getStreamHistory(@PathVariable Long userId) {
         List<Stream> history = streamService.getStreamHistory(userId);

src/main/java/com/ddf/vodsystem/controllers/input/ClipSectionRequest.java

@@ -0,0 +1,7 @@
+package com.ddf.vodsystem.controllers.input;
+
+import jakarta.validation.constraints.NotNull;
+
+public record ClipSectionRequest(
+        @NotNull float duration
+) {}

src/main/java/com/ddf/vodsystem/controllers/input/SaveSectionRequest.java

@@ -0,0 +1,8 @@
+package com.ddf.vodsystem.controllers.input;
+
+import java.time.Instant;
+import jakarta.validation.constraints.NotNull;
+
+public record SaveSectionRequest(
+        @NotNull Instant startTime,
+        @NotNull Instant endTime) {}

src/main/java/com/ddf/vodsystem/dto/SaveSectionRequest.java

@@ -1,5 +0,0 @@
-package com.ddf.vodsystem.dto;
-
-import java.time.Instant;
-
-public record SaveSectionRequest(Instant startTime, Instant endTime) {}

src/main/java/com/ddf/vodsystem/services/StreamService.java

@@ -17,6 +17,7 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.io.File;
 import java.io.IOException;
+import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDateTime;
 import java.util.Arrays;
@@ -28,7 +29,9 @@ import java.util.stream.Collectors;
 @Service
 public class StreamService {
     private static final Logger logger = LoggerFactory.getLogger(StreamService.class);
+
     private static final int HEARTBEAT_TIMEOUT_SECONDS = 60;
+    private static final float CLIP_MAX_LENGTH = 180;
 
     private final StreamRepository streamRepository;
     private final UserService userService;
@@ -118,6 +121,34 @@ public class StreamService {
                 });
     }
 
+    public void clip(float duration) throws IOException, InterruptedException {
+        if (duration <= 0 || duration > CLIP_MAX_LENGTH) {
+            throw new IllegalArgumentException("Clip length must be between 0 and " + CLIP_MAX_LENGTH + " seconds");
+        }
+
+        User user = userService.getLoggedInUser()
+                .orElseThrow(() -> new NotAuthenticated("User is not authenticated"));
+
+        Instant endTime = Instant.now();
+        // minusSeconds() is possible, but only does integer seconds, not float
+        Instant startTime = Instant.now().minus(Duration.ofMillis((long) (duration * 1000)));
+
+        String streamDirectory = streamDataPath + File.separator + user.getStreamKey();
+        List<File> fileSegments = getSegmentsInRange(streamDirectory, startTime, endTime);
+
+        if (fileSegments.isEmpty()) {
+            throw new IllegalArgumentException("No stream segments found in the given time range");
+        }
+
+        long firstSegmentMs = parseTimestampMs(fileSegments.getFirst());
+        float trimOffset = Math.max(0f, (startTime.toEpochMilli() - firstSegmentMs) / 1000f);
+
+        streamActionsService.saveSection(fileSegments, trimOffset, duration)
+                .exceptionally(ex -> {
+                    throw new FFMPEGException("Saving stream section failed due to FFMPEG Error");
+                });
+    }
+
     @Scheduled(fixedDelay = 30_000)
     @Transactional
     public void endStaleStreams() {