1 files changed, 36 insertions, 13 deletions

diff --git a/app/src/main/java/mygram/droid/Api.java b/app/src/main/java/mygram/droid/Api.java
index 7cce5b6..f603b1b 100644
--- a/app/src/main/java/mygram/droid/Api.java
+++ b/app/src/main/java/mygram/droid/Api.java
@@ -165,15 +165,42 @@ final class Api {
 		return out;
 	}
 
-	/** Every post of a folder, in server order. */
-	static List<Post> folderPosts(String slug) throws IOException, JSONException {
-		List<Post> all = new ArrayList<>();
-		for (int page = 1;; page++) {
-			JSONObject o = call("GET", "/folders/" + Uri.encode(slug) + "/images?limit=" + PAGE + "&page=" + page);
-			all.addAll(Post.list(o, Prefs.server()));
-			if (!o.optBoolean("hasMore"))
-				return all;
-		}
+	/** Pager over a folder: each call returns the next page, shuffled; empty once all pages are used. */
+	// ponytail: random page order plus in-page shuffle, not a full shuffle; neighbours within a page stay together; upgrade: fetch all ids once if that ever matters.
+	static Callable<List<Post>> folderPages(String slug, int count) {
+		List<Integer> pages = new ArrayList<>();
+		for (int p = 1; p <= (count + PAGE - 1) / PAGE; p++)
+			pages.add(p);
+		Collections.shuffle(pages);
+		String path = "/folders/" + Uri.encode(slug) + "/images?limit=" + PAGE + "&page=";
+		int[] next = {0};
+		return () -> {
+			synchronized (next) {
+				while (next[0] < pages.size()) { // imageCount counts carousel slides, so later pages may be empty
+					List<Post> posts = Post.list(call("GET", path + pages.get(next[0]++)), Prefs.server());
+					if (!posts.isEmpty()) {
+						Collections.shuffle(posts);
+						return posts;
+					}
+				}
+				return new ArrayList<>();
+			}
+		};
+	}
+
+	/** Pager over random Reels with a fixed seed; empty once the server reports no more. */
+	static Callable<List<Post>> reelsPages(int seed) {
+		int[] state = {0, 1}; // page, hasMore
+		return () -> {
+			synchronized (state) {
+				if (state[1] == 0)
+					return new ArrayList<>();
+				JSONObject o = call("GET", "/reels?mode=random&limit=12&seed=" + seed + "&page=" + ++state[0]);
+				if (!o.optBoolean("hasMore"))
+					state[1] = 0;
+				return Post.list(o, Prefs.server());
+			}
+		};
 	}
 
 	/** Up to n random posts of a folder. */
@@ -193,10 +220,6 @@ final class Api {
 		return Post.list(call("GET", "/feed?mode=random&limit=" + PAGE), Prefs.server());
 	}
 
-	static JSONObject reels(int seed, int page) throws IOException, JSONException {
-		return call("GET", "/reels?mode=random&limit=12&seed=" + seed + "&page=" + page);
-	}
-
 	/** Liked posts, newest like first. */
 	static List<Post> likes() throws IOException, JSONException {
 		return Post.list(call("GET", "/likes"), Prefs.server());