diff --git a/db/migrations/10_next_ids.sql b/db/migrations/10_next_ids.sql
new file mode 100644
index 0000000..430a1e6
--- /dev/null
+++ b/db/migrations/10_next_ids.sql
@@ -0,0 +1,8 @@
+-- +migrate up
+CREATE TABLE next_id (
+  name  TEXT     NOT NULL,
+  id    INTEGER  NOT NULL  DEFAULT 0
+);
+
+-- +migrate down
+DROP TABLE next_id;
\ No newline at end of file
diff --git a/src/crystal-gauntlet.cr b/src/crystal-gauntlet.cr
index aac999e..51d5ebd 100644
--- a/src/crystal-gauntlet.cr
+++ b/src/crystal-gauntlet.cr
@@ -14,6 +14,7 @@ require "./lib/accounts"
 require "./lib/gjp"
 require "./lib/clean"
 require "./lib/songs"
+require "./lib/ids"
 
 Dotenv.load
 
@@ -94,7 +95,7 @@ module CrystalGauntlet
 
       body = context.request.body
 
-      if CrystalGauntlet.endpoints.has_key?(path) && body
+      if CrystalGauntlet.endpoints.has_key?(path) && context.request.method == "POST" && body
         func = CrystalGauntlet.endpoints[path]
         value = func.call(body.gets_to_end)
         LOG.debug { "-> " + value }
diff --git a/src/endpoints/accounts/registerAccount.cr b/src/endpoints/accounts/registerAccount.cr
index 303110d..c9d420d 100644
--- a/src/endpoints/accounts/registerAccount.cr
+++ b/src/endpoints/accounts/registerAccount.cr
@@ -26,10 +26,10 @@ CrystalGauntlet.endpoints["/accounts/registerGJAccount.php"] = ->(body : String)
 
   password_hash = Crypto::Bcrypt::Password.create(password, cost: 10).to_s
   gjp2 = CrystalGauntlet::GJP.hash(password)
-  next_id = (DATABASE.scalar("select max(id) from accounts").as(Int64 | Nil) || 0) + 1
+  next_id = IDs.get_next_id("accounts")
   DATABASE.exec "insert into accounts (id, username, password, email, gjp2) values (?, ?, ?, ?, ?)", next_id, username, password_hash, email, gjp2
 
-  user_id = (DATABASE.scalar("select max(id) from users").as(Int64 | Nil) || 0) + 1
+  user_id = IDs.get_next_id("users")
   DATABASE.exec "insert into users (id, account_id, username, registered) values (?, ?, ?, 1)", user_id, next_id, username
   "1"
 }
diff --git a/src/endpoints/levels/addLevelComment.cr b/src/endpoints/levels/addLevelComment.cr
index 6d50d8e..cea1763 100644
--- a/src/endpoints/levels/addLevelComment.cr
+++ b/src/endpoints/levels/addLevelComment.cr
@@ -22,7 +22,7 @@ CrystalGauntlet.endpoints["/uploadGJComment21.php"] = ->(body : String): String
   if comment && comment != ""
     # todo: cap comment size
     comment_value = Base64.decode_string comment # usual b64, surprisingly
-    next_id = (DATABASE.scalar("select max(id) from comments").as(Int64 | Nil) || 0) + 1
+    next_id = IDs.get_next_id("comments")
     DATABASE.exec("insert into comments (id, level_id, user_id, comment, percent) values (?, ?, ?, ?, ?)", next_id, level_id, user_id, comment_value, percent)
     return "1"
   else
diff --git a/src/endpoints/levels/downloadLevel.cr b/src/endpoints/levels/downloadLevel.cr
index 8f470ad..d0acc9b 100644
--- a/src/endpoints/levels/downloadLevel.cr
+++ b/src/endpoints/levels/downloadLevel.cr
@@ -98,7 +98,7 @@ CrystalGauntlet.endpoints["/downloadGJLevel22.php"] = ->(body : String): String
       })
       response << Hashes.gen_solo(level_data)
 
-      thing = [user_id, stars || 0, (difficulty && difficulty.demon?) || 0, id, rated_coins, featured, password, 0].map! { |x| Format.fmt_value(x) }
+      thing = [user_id, stars || 0, (difficulty && difficulty.demon?) || 0, id, rated_coins, featured, password, 0].map { |x| Format.fmt_value(x) }
       response << Hashes.gen_solo_2(thing.join(","))
 
       return response.join("#")
diff --git a/src/endpoints/levels/getLevels.cr b/src/endpoints/levels/getLevels.cr
index e311e53..84dee7f 100644
--- a/src/endpoints/levels/getLevels.cr
+++ b/src/endpoints/levels/getLevels.cr
@@ -44,7 +44,7 @@ CrystalGauntlet.endpoints["/getGJLevels21.php"] = ->(body : String): String {
   end
   if params["song"]?
     if params["customSong"]? && params["customSong"]? != ""
-      # todo
+      queryParams << "song_id = '#{params["customSong"].to_i}'"
     else
       queryParams << "song_id = '#{params["song"].to_i}'"
     end
@@ -86,7 +86,8 @@ CrystalGauntlet.endpoints["/getGJLevels21.php"] = ->(body : String): String {
       queryParams << "difficulty = #{LevelDifficulty::Auto.value} or (difficulty is null and community_difficulty = #{LevelDifficulty::Auto.value})"
     else
       # easy, normal, hard, harder, insane
-      # todo
+      diffs = params["diff"].split(",").map{ |v| v.to_i }.join(",")
+      queryParams << "difficulty in (#{diffs}) or (difficulty is null and community_difficulty in (#{diffs}))"
     end
   end
 
@@ -99,7 +100,9 @@ CrystalGauntlet.endpoints["/getGJLevels21.php"] = ->(body : String): String {
   when "2" # most liked
     order = "likes desc"
   when "3" # trending
-    # todo
+    # todo: make configurable?
+    order = "likes desc"
+    queryParams << "created_at > #{(Time.utc - 7.days).to_s(Format::TIME_FORMAT)}"
   when "5" # made by user
     queryParams << "levels.user_id = #{searchQuery.to_i}" # (you can't sql inject with numbers)
   when "6", "17" # featured (gdw is 17)
@@ -109,7 +112,8 @@ CrystalGauntlet.endpoints["/getGJLevels21.php"] = ->(body : String): String {
     # todo: order by epic date
     queryParams << "epic = 1"
   when "7" # magic
-    # todo
+    # todo: make configurable?
+    queryParams << "objects > 4000"
   when "10", "19" # map packs
     order = "map_pack_links.idx asc"
     queryParams << "levels.id in (#{searchQuery.split(",").map{|v| v.to_i}.join(",")})"
@@ -215,7 +219,6 @@ CrystalGauntlet.endpoints["/getGJLevels21.php"] = ->(body : String): String {
   searchMeta = "#{level_count}:#{page_offset}:#{levels_per_page}"
 
   res = [results.join("|"), users.join("|"), songs.join("~:~"), searchMeta, CrystalGauntlet::Hashes.gen_multi(hash_data)].join("#")
-  LOG.debug { res }
 
   res
 }
diff --git a/src/endpoints/levels/uploadLevel.cr b/src/endpoints/levels/uploadLevel.cr
index 4734131..4fbca5b 100644
--- a/src/endpoints/levels/uploadLevel.cr
+++ b/src/endpoints/levels/uploadLevel.cr
@@ -50,7 +50,7 @@ CrystalGauntlet.endpoints["/uploadGJLevel21.php"] = ->(body : String): String {
     raise "not implemented"
   else
     # create new level
-    next_id = (DATABASE.scalar("select max(id) from levels").as(Int64 | Nil) || 0) + 1
+    next_id = IDs.get_next_id("levels")
 
     DATABASE.exec("insert into levels (id, name, user_id, description, original, game_version, binary_version, password, requested_stars, unlisted, version, level_data, extra_data, level_info, wt1, wt2, song_id, length, objects, coins, has_ldm, two_player) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)", next_id, Clean.clean_special(params["levelName"]), user_id, description, params["original"].to_i32, params["gameVersion"].to_i32, params["binaryVersion"].to_i32, params["password"] == "0" ? nil : params["password"].to_i32, params["requestedStars"].to_i32, params["unlisted"].to_i32, params["levelVersion"].to_i32, Clean.clean_b64(params["levelString"]), Clean.clean_special(extraString), Clean.clean_b64(params["levelInfo"]), Clean.clean_number(params["wt"]), Clean.clean_number(params["wt2"]), song_id.to_i32, params["levelLength"].to_i32, params["objects"].to_i32, params["coins"].to_i32, params["ldm"].to_i32, params["twoPlayer"].to_i32)
 
diff --git a/src/endpoints/users/addProfileComment.cr b/src/endpoints/users/addProfileComment.cr
index 2551aba..9f8e212 100644
--- a/src/endpoints/users/addProfileComment.cr
+++ b/src/endpoints/users/addProfileComment.cr
@@ -16,7 +16,7 @@ CrystalGauntlet.endpoints["/uploadGJAccComment20.php"] = ->(body : String): Stri
   if comment && comment != ""
     # todo: cap comment size
     comment_value = Base64.decode_string comment # usual b64, surprisingly
-    next_id = (DATABASE.scalar("select max(id) from account_comments").as(Int64 | Nil) || 0) + 1
+    next_id = IDs.get_next_id("account_comments")
     DATABASE.exec("insert into account_comments (id, account_id, comment) values (?, ?, ?)", next_id, account_id, comment_value)
     return "1"
   else
diff --git a/src/lib/ids.cr b/src/lib/ids.cr
new file mode 100644
index 0000000..7eb4340
--- /dev/null
+++ b/src/lib/ids.cr
@@ -0,0 +1,19 @@
+include CrystalGauntlet
+
+module CrystalGauntlet::IDs
+  extend self
+
+  def get_next_id(key : String) : Int32
+    begin
+      id = DATABASE.query_one("select id from next_id where name = ?", key, as: {Int32})
+    rescue
+      next_id = 1
+      DATABASE.exec("insert into next_id (name, id) values (?, ?)", key, next_id)
+      next_id
+    else
+      next_id = id + 1
+      DATABASE.exec("update next_id set id = ?", next_id)
+      return next_id
+    end
+  end
+end
diff --git a/src/lib/songs.cr b/src/lib/songs.cr
index 8c17b04..6baee63 100644
--- a/src/lib/songs.cr
+++ b/src/lib/songs.cr
@@ -102,7 +102,7 @@ module CrystalGauntlet::Songs
     begin
       DATABASE.query_one("select id from song_authors where name = ? and url = ? and source = ?", artist_name, artist_url, source, as: {Int32})
     rescue
-      next_id = (DATABASE.scalar("select max(id) from song_authors").as(Int64 | Nil) || 0) + 1
+      next_id = IDs.get_next_id("song_authors")
       DATABASE.exec("insert into song_authors (id, source, name, url) values (?, ?, ?, ?)", next_id, source, artist_name, artist_url)
       next_id.to_i
     end