chuni: Correctly implement recent rating requests

schema/init/cm.sql

@@ -357,3 +357,16 @@ create table "cm_user_playlog" (
     "place_name" text not null,
     "is_maimai" text not null
 );
+
+create table "cm_user_recent_rating" (
+    "id" integer primary key not null,
+    "profile_id" integer not null
+            references "cm_user_data"("id")
+            on delete cascade,
+    "sort_order" integer not null,
+    "music_id" integer not null,
+    "difficult_id" integer not null,
+    "rom_version_code" integer not null,
+    "score" integer not null,
+    constraint "cm_user_recent_rating_uq" unique ("profile_id", "sort_order")
+);

schema/migrate/M0015-cm-user-recent-rating.sql

@@ -0,0 +1,31 @@
+create table if not exists "cm_user_recent_rating" (
+    "id" integer primary key not null,
+    "profile_id" integer not null
+            references "cm_user_data"("id")
+            on delete cascade,
+    "sort_order" integer not null,
+    "music_id" integer not null,
+    "difficult_id" integer not null,
+    "rom_version_code" integer not null,
+    "score" integer not null,
+    constraint "cm_user_recent_rating_uq" unique ("profile_id", "sort_order")
+);
+
+-- Prepopulate this table by backfilling the most recent 30 scores per user.
+-- This isn't exactly correct since not every recent score should go in here, but it's probably close enough.
+INSERT INTO cm_user_recent_rating (profile_id, sort_order, music_id, difficult_id, rom_version_code, score)
+SELECT * FROM (
+    SELECT
+        profile_id,
+        row_number()
+            OVER (PARTITION BY profile_id ORDER BY user_play_date DESC) AS sort_order,
+        music_id,
+        level AS difficult_id,
+        '1030000' AS rom_version_code,
+    score
+    FROM cm_user_playlog
+    WHERE
+        difficult_id < 4    -- skip world's end
+    ORDER BY profile_id ASC, user_play_date DESC
+)
+WHERE sort_order <= 30;