Add daily stock lot sellout forecast

db/migrations/0016_stock_lot_forecast_history.sql

@@ -0,0 +1,50 @@
+BEGIN;
+
+ALTER TABLE stock_lot
+  ADD COLUMN IF NOT EXISTS sellout_forecast_status TEXT NOT NULL DEFAULT 'no_demand',
+  ADD COLUMN IF NOT EXISTS sellout_forecast_confidence TEXT NOT NULL DEFAULT 'none',
+  ADD COLUMN IF NOT EXISTS sellout_forecast_daily_demand NUMERIC(14, 6) NOT NULL DEFAULT 0,
+  ADD COLUMN IF NOT EXISTS sellout_forecast_calculated_at TIMESTAMP;
+
+DO $$
+BEGIN
+  IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'chk_stock_lot_forecast_status') THEN
+    ALTER TABLE stock_lot ADD CONSTRAINT chk_stock_lot_forecast_status
+      CHECK (sellout_forecast_status IN ('forecast', 'depleted', 'no_demand'));
+  END IF;
+  IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'chk_stock_lot_forecast_confidence') THEN
+    ALTER TABLE stock_lot ADD CONSTRAINT chk_stock_lot_forecast_confidence
+      CHECK (sellout_forecast_confidence IN ('high', 'medium', 'low', 'none'));
+  END IF;
+END;
+$$;
+
+CREATE TABLE IF NOT EXISTS stock_lot_forecast_history (
+  id BIGSERIAL PRIMARY KEY,
+  stock_lot_id BIGINT NOT NULL REFERENCES stock_lot(id) ON DELETE RESTRICT,
+  product_id BIGINT NOT NULL REFERENCES product(id) ON DELETE RESTRICT,
+  calculated_at TIMESTAMP NOT NULL DEFAULT NOW(),
+  as_of_date DATE NOT NULL,
+  physical_qty NUMERIC(14, 4) NOT NULL,
+  weighted_daily_demand NUMERIC(14, 6) NOT NULL DEFAULT 0,
+  sales_units NUMERIC(14, 4) NOT NULL DEFAULT 0,
+  sales_days INTEGER NOT NULL DEFAULT 0,
+  observed_span_days INTEGER NOT NULL DEFAULT 0,
+  lookback_days INTEGER NOT NULL,
+  half_life_days INTEGER NOT NULL,
+  forecast_date DATE,
+  forecast_status TEXT NOT NULL,
+  confidence TEXT NOT NULL,
+  error_message TEXT,
+  CONSTRAINT chk_stock_lot_forecast_history_status
+    CHECK (forecast_status IN ('forecast', 'depleted', 'no_demand')),
+  CONSTRAINT chk_stock_lot_forecast_history_confidence
+    CHECK (confidence IN ('high', 'medium', 'low', 'none'))
+);
+
+CREATE INDEX IF NOT EXISTS idx_stock_lot_forecast_history_lot_date
+  ON stock_lot_forecast_history(stock_lot_id, calculated_at DESC);
+CREATE INDEX IF NOT EXISTS idx_stock_lot_forecast_history_product_date
+  ON stock_lot_forecast_history(product_id, calculated_at DESC);
+
+COMMIT;