Implement randomTime for videos that don't exist in dearrow.

src/main/java/me/kavin/piped/utils/Alea.java

@@ -0,0 +1,50 @@
+package me.kavin.piped.utils;
+
+public class Alea {
+
+    private static final double NORM32 = 2.3283064365386963e-10; // 2^-32
+    private double s0, s1, s2;
+    private int c = 1;
+
+    public double next() {
+        double t = 2091639.0 * s0 + c * NORM32; // 2^-32
+        s0 = s1;
+        s1 = s2;
+        return s2 = t - (c = (int) t);
+    }
+
+    public Alea(String seed) {
+        s0 = mash(" ");
+        s1 = mash(" ");
+        s2 = mash(" ");
+
+        s0 -= mash(seed);
+
+        if (s0 < 0)
+            s0 += 1;
+        s1 -= mash(seed);
+        if (s1 < 0)
+            s1 += 1;
+        s2 -= mash(seed);
+        if (s2 < 0)
+            s2 += 1;
+    }
+
+    private long n = 0xefc8249dL;
+
+    public double mash(String x) {
+        double h;
+
+        for (char c : x.toCharArray()) {
+            n += c;
+            h = 0.02519603282416938 * n;
+            n = (long) h;
+            h -= n;
+            h *= n;
+            n = (long) h;
+            h -= n;
+            n += h * 0x100000000L;
+        }
+        return n * 2.3283064365386963e-10; // 2^-32
+    }
+}

src/main/java/me/kavin/piped/utils/SponsorBlockUtils.java

@@ -85,6 +85,15 @@ public class SponsorBlockUtils {
 
     }
 
+    private static final ObjectNode EMPTY_DEARROWED_INFO;
+
+    static {
+        EMPTY_DEARROWED_INFO = mapper.createObjectNode();
+        EMPTY_DEARROWED_INFO.putArray("titles");
+        EMPTY_DEARROWED_INFO.putArray("thumbnails");
+        EMPTY_DEARROWED_INFO.set("videoDuration", NullNode.getInstance());
+    }
+
     private static void fetchDeArrowedCf(CompletableFuture<Optional<JsonNode>> future, String videoId, String hash, String[] servers) {
 
         var completableFuture = RequestUtils.sendGetJson(servers[0] + "/api/branding/" + URLUtils.silentEncode(hash.substring(0, 4)))
@@ -98,6 +107,15 @@ public class SponsorBlockUtils {
             }
         }));
 
+        completableFuture = completableFuture.thenApplyAsync(optional -> {
+            if (optional.isEmpty()) {
+                var clone = EMPTY_DEARROWED_INFO.deepCopy();
+                clone.put("randomTime", new Alea(videoId).next());
+                return Optional.of(clone);
+            } else
+                return optional;
+        });
+
 
         completableFuture.whenComplete((optional, throwable) -> {
             if (throwable == null)