-- Migration 038: Add data-quality columns to stock_observations + selective cleanup
--
-- stock_confidence:    1 = boolean only (in_stock true/false)
--                      2 = aggregated global count (single number, e.g. QSFPTEK)
--                      3 = per-warehouse breakdown (e.g. FS.com DE/Global split)
-- price_currency:      ISO 4217 code, e.g. 'USD', 'EUR', 'GBP'
-- price_includes_tax:  true = gross price, false = net/excl. VAT
-- stock_vendor_ts:     timestamp as reported by vendor (e.g. QSFPTEK "17 Apr 2026")

ALTER TABLE stock_observations
  ADD COLUMN IF NOT EXISTS stock_confidence   SMALLINT     DEFAULT 1
    CHECK (stock_confidence IN (1, 2, 3)),
  ADD COLUMN IF NOT EXISTS price_currency     CHAR(3),
  ADD COLUMN IF NOT EXISTS price_includes_tax BOOLEAN,
  ADD COLUMN IF NOT EXISTS stock_vendor_ts    TIMESTAMPTZ;

-- ── Selective cleanup ───────────────────────────────────────────────────────
-- Truncate stock_observations: all 186 rows are from the first FS.com test run.
-- They will be repopulated automatically at the next scheduled scraper run
-- (02:00 / 10:00 / 18:00 via launchd). Transceiver catalog, specs, vendors,
-- price_observations, and all other tables are left untouched.
TRUNCATE TABLE stock_observations;