Write SQL window functions for D7 retention

Assume you have the following tables (timestamps are in UTC). **1) game_sessions** - user_id (STRING) - session_start_ts (TIMESTAMP) - country (STRING) Each row is one play session. **2) ad_impressions** - user_id (STRING) - impression_ts (TIMESTAMP) - ad_type (STRING) -- e.g., 'rewarded', 'interstitial' - revenue_usd (DECIMAL(10,4)) Each row is one ad impression. Write a SQL query (window functions encouraged) that outputs **one row per user** with: - user_id - first_play_date (DATE) = the user’s first session date - retained_d7 (INT) = 1 if the user had **any** session on (first_play_date + 7 days), else 0 - ad_revenue_first_7d (DECIMAL) = total ad revenue from impressions with impression_ts in [first_play_ts, first_play_ts + 7 days) - country - revenue_rank_in_country (INT) = rank users within each country by ad_revenue_first_7d (highest revenue rank = 1) Notes: - If a user has no ad impressions, ad_revenue_first_7d should be 0. - Define ties in ranking using dense rank.