-- ============================================================
-- CS2 Skin Tracker — backfill skin_conditions.listings_swept_at
-- Run against the skintracker database as the app role, ONCE,
-- after the AddSkinConditionListingsSweptAt migration is applied
-- and 05_fill_skin_conditions.sql has populated the wear bands.
-- Idempotent: re-running only touches still-null bands.
--
-- Why: the catalogue sweep used to page each skin to completion
-- as a single unit, so a non-null skins.listings_swept_at means
-- EVERY wear of that skin was covered at that time. The sweep now
-- checkpoints per wear band (skin_conditions.listings_swept_at).
-- Without this backfill, every band of an already-swept skin would
-- look never-swept and jump to the front of the queue, needlessly
-- re-sweeping skins that are already current. Inheriting the skin's
-- timestamp marks those bands as covered so the sweep moves on.
--
-- Only fills bands that are still null, so bands already swept under
-- the new per-band logic keep their (newer) timestamp.
-- ============================================================

SET search_path = skintracker;

UPDATE skin_conditions sc
SET listings_swept_at = s.listings_swept_at
FROM skins s
WHERE sc.skin_id = s.id
  AND s.listings_swept_at IS NOT NULL   -- skin was fully swept under the old per-skin logic
  AND sc.listings_swept_at IS NULL;     -- don't overwrite bands already swept per-band

-- ------------------------------------------------------------
-- Sanity checks (optional)
-- ------------------------------------------------------------
-- Bands backfilled vs still never-swept:
-- SELECT
--   count(*) FILTER (WHERE listings_swept_at IS NOT NULL) AS swept,
--   count(*) FILTER (WHERE listings_swept_at IS NULL)     AS never_swept
-- FROM skin_conditions;
--
-- A previously-swept skin should now have all its bands stamped:
-- SELECT s.name, sc.condition, sc.listings_swept_at
-- FROM skin_conditions sc JOIN skins s ON s.id = sc.skin_id
-- WHERE s.listings_swept_at IS NOT NULL
-- ORDER BY s.name, sc.min_float
-- LIMIT 20;