feat: add ranked season maintenance role

server/store/maintenance_sql.go

@@ -0,0 +1,67 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/cosmic-clash/cosmic-clash/server/domain"
+)
+
+const DueSeasonRolloversSQL = `SELECT s.season_id, r.player_id, r.rating, r.deviation,
+    r.volatility, r.ranked_games
+FROM seasons s
+CROSS JOIN ratings r
+LEFT JOIN ranked_season_rollovers rr ON rr.season_id = s.season_id AND rr.player_id = r.player_id
+WHERE s.playlist = 'ranked' AND s.ends_at <= $1 AND rr.player_id IS NULL
+ORDER BY s.ends_at, s.season_id, r.player_id
+LIMIT $2`
+
+const MarkSeasonRolledOverSQL = `UPDATE seasons SET rolled_over_at = $2
+WHERE season_id = $1 AND rolled_over_at IS NULL
+  AND NOT EXISTS (SELECT 1 FROM ratings r
+                  LEFT JOIN ranked_season_rollovers rr ON rr.season_id = $1 AND rr.player_id = r.player_id
+                  WHERE rr.player_id IS NULL)`
+
+type dueSeasonRollover struct {
+	seasonID string
+	playerID string
+	profile  domain.RankedProfile
+}
+
+// RolloverDueSeasons processes a bounded batch. Each player update is its own
+// exactly-once SERIALIZABLE transaction, so a worker crash can safely resume.
+func RolloverDueSeasons(ctx context.Context, db *sql.DB, now time.Time, limit int) (int, error) {
+	if db == nil || now.IsZero() || limit < 1 || limit > 1000 {
+		return 0, fmt.Errorf("invalid season maintenance arguments")
+	}
+	rows, err := db.QueryContext(ctx, DueSeasonRolloversSQL, now, limit)
+	if err != nil {
+		return 0, err
+	}
+	defer rows.Close()
+	var due []dueSeasonRollover
+	for rows.Next() {
+		var item dueSeasonRollover
+		if err := rows.Scan(&item.seasonID, &item.playerID, &item.profile.Value, &item.profile.RD, &item.profile.Volatility, &item.profile.RankedGames); err != nil {
+			return 0, err
+		}
+		due = append(due, item)
+	}
+	if err := rows.Err(); err != nil {
+		return 0, err
+	}
+	count := 0
+	for _, item := range due {
+		if _, applied, err := ApplyRankedSeasonRollover(ctx, db, item.playerID, item.seasonID, item.profile, now); err != nil {
+			return count, err
+		} else if applied {
+			count++
+		}
+		if _, err := db.ExecContext(ctx, MarkSeasonRolledOverSQL, item.seasonID, now); err != nil {
+			return count, err
+		}
+	}
+	return count, nil
+}