Implement rating change updates to DB

Still missing: The actual function to calculate the rating change

install/database_schema.sql

@@ -260,7 +260,7 @@ CREATE TABLE variant_base_ratings (
 DROP TABLE IF EXISTS variant_ratings CASCADE;
 CREATE TABLE variant_ratings (
   /** This should reference the game that triggered the elo update */
-  league_id INTEGER PRIMARY KEY REFERENCES games,
+  league_id INTEGER PRIMARY KEY REFERENCES games (league_id),
 
   variant_id SMALLINT NOT NULL,
   player_count SMALLINT NOT NULL,
@@ -293,7 +293,7 @@ CREATE TABLE user_ratings (
   * I would use the league_id here for proper ordering.
   * Also note that this can then be used to identify whether a given league game has already been processed for rating change.
   */
-  league_id INTEGER PRIMARY KEY REFERENCES games,
+  league_id INTEGER REFERENCES games (league_id),
 
   user_id SMALLINT NOT NULL,
   type SMALLINT NOT NULL,
@@ -301,12 +301,15 @@ CREATE TABLE user_ratings (
   /**
   * Do we want to store this here as well? Would be nice to be displayed in some elo page imo.
   * Note: We don't need to store the result (i guess), since we can easily retrieve that info by looking up the game using the league_id
+  * TODO: Since I'm not even sure on the rating model yet (I could imagine something slightly different than a team rating),
+  * I'll leave this here as potentially null for now and don't implement it.
   */
-  team_rating REAL NOT NULL,
+  team_rating REAL,
   change REAL NOT NULL,
   value_after REAL NOT NULL,
 
-  FOREIGN KEY (user_id) REFERENCES users (id)
+  FOREIGN KEY (user_id) REFERENCES users (id),
+  CONSTRAINT user_change_per_game_unique UNIQUE (league_id, user_id)
 );
 
 

ratings.py

@@ -1,11 +1,24 @@
-from typing import List, Dict
+from typing import List, Dict, Tuple
 
 import utils
 from database import conn_manager
+import psycopg2.extras
 
 from log_setup import logger
 
 
+def rating_change(user_ratings: Dict[int, float], variant_rating: float, win: bool) -> Tuple[Dict[int, float], float]:
+    """
+    @param user_ratings: Mapping of user ids to ratings that played this game.
+    @param variant_rating: Rating of the variant that was played
+    @param win: Whether the team won the game
+    @return: Mapping of user ids to their rating *changes* and *change* in variant rating
+    """
+    # TODO: Implement this properly (We have not decided how this will work exactly)
+    # For now, return +1 elo for players and -1 elo for variants
+    return {user_id: 1 for user_id in user_ratings.keys()}, -1
+
+
 def next_game_to_rate():
     cur = conn_manager.get_new_cursor()
     cur.execute("SELECT games.id FROM games "
@@ -23,7 +36,7 @@ def next_game_to_rate():
     return game_id
 
 
-def get_current_ratings(user_ids: List[int], rating_type: int) -> Dict[int, float]:
+def get_current_user_ratings(user_ids: List[int], rating_type: int) -> Dict[int, float]:
     """
     Fetches the current ratings for specified players and rating type from DB
     @return: Mapping user_id -> current rating
@@ -41,6 +54,8 @@ def get_current_ratings(user_ids: List[int], rating_type: int) -> Dict[int, floa
                 "    GROUP BY (user_id, type)"
                 "  ) AS latest_user_ratings "
                 "  ON user_ratings.league_id = latest_user_ratings.max_league_id "
+                "WHERE user_ratings.user_id IN ({}) AND user_ratings.type = %s".format(", ".join("%s" for _ in user_ids)),
+                user_ids + [rating_type]
                 )
     current_ratings = cur.fetchall()
 
@@ -53,6 +68,38 @@ def get_current_ratings(user_ids: List[int], rating_type: int) -> Dict[int, floa
     return ratings
 
 
+def get_current_variant_rating(variant_id: int, player_count: int) -> float:
+    cur = conn_manager.get_new_cursor()
+    cur.execute("SELECT value_after FROM variant_ratings "
+                "INNER JOIN ("
+                "    SELECT variant_id, player_count, MAX(league_id) AS max_league_id"
+                "    FROM variant_ratings "
+                "    GROUP BY (variant_id, player_count)"
+                "  ) AS latest_variant_ratings "
+                "  ON variant_ratings.league_id = latest_variant_ratings.max_league_id "
+                "WHERE variant_ratings.variant_id = %s AND variant_ratings.player_count = %s",
+                (variant_id, player_count)
+                )
+    query_result = cur.fetchone()
+    if query_result is not None:
+        (current_rating, ) = query_result
+        return current_rating
+
+    # Reaching this point of code execution just means this is the first game for this variant rating
+    cur.execute("SELECT rating FROM variant_base_ratings "
+                "WHERE variant_id = %s AND player_count = %s",
+                (variant_id, player_count)
+                )
+    query_result = cur.fetchone()
+    if query_result is None:
+        err_msg = "Failed to get current variant rating for variant {}.".format(variant_id)
+        logger.error(err_msg)
+        raise ValueError(err_msg)
+
+    (base_rating, ) = query_result
+    return base_rating
+
+
 def process_rating_of_next_game():
     game_id = next_game_to_rate()
     if game_id is None:
@@ -60,14 +107,16 @@ def process_rating_of_next_game():
         return
     logger.verbose("Processing rating for game {}".format)
     cur = conn_manager.get_new_cursor()
-    cur.execute("SELECT games.league_id, games.num_players, games.score, variants.num_suits, variants.clue_starved "
+    # Fetch data on the game played
+    cur.execute(
+        "SELECT games.league_id, games.num_players, games.score, variants.num_suits, variants.clue_starved, variants.id "
         "FROM games "
         "INNER JOIN variants "
         "  ON games.variant_id = variants.id "
         "WHERE games.id = %s",
         (game_id,)
         )
-    league_id, num_players, score, num_suits, clue_starved = cur.fetchone()
+    league_id, num_players, score, num_suits, clue_starved, variant_id = cur.fetchone()
 
     cur.execute("SELECT game_participants.user_id FROM games "
                 "INNER JOIN game_participants "
@@ -84,4 +133,23 @@ def process_rating_of_next_game():
         raise ValueError(err_msg)
 
     rating_type = utils.get_rating_type(clue_starved)
-    ratings = get_current_ratings(user_ids, rating_type)
+    user_ratings = get_current_user_ratings(user_ids, rating_type)
+    variant_rating = get_current_variant_rating(variant_id, num_players)
+
+    user_changes, variant_change = rating_change(user_ratings, variant_rating, score == 5 * num_suits)
+    cur.execute("INSERT INTO variant_ratings (league_id, variant_id, player_count, change, value_after) "
+                "VALUES (%s, %s, %s, %s, %s)",
+                (league_id, variant_id, num_players, variant_change, variant_rating + variant_change)
+                )
+
+    user_ratings_vals = []
+    for user_id, change in user_changes.items():
+        user_ratings_vals.append((league_id, user_id, rating_type, change, user_ratings[user_id] + change))
+
+    psycopg2.extras.execute_values(
+        cur,
+        "INSERT INTO user_ratings (league_id, user_id, type, change, value_after) "
+        "VALUES %s",
+        user_ratings_vals
+    )
+    conn_manager.get_connection().commit()