-- ABOUTME: Migration to create feed_inventory table.
-- ABOUTME: Tracks feed purchases, amounts given, and current balance.

-- Feed inventory tracks global feed levels per type
-- Stores amounts in kg, prices in cents
CREATE TABLE feed_inventory (
    feed_type_code TEXT PRIMARY KEY REFERENCES feed_types(code),
    purchased_kg INTEGER NOT NULL DEFAULT 0,
    given_kg INTEGER NOT NULL DEFAULT 0,
    balance_kg INTEGER NOT NULL DEFAULT 0,
    last_purchase_price_per_kg_cents INTEGER,
    last_purchase_at_utc INTEGER,
    last_given_at_utc INTEGER,
    updated_at_utc INTEGER NOT NULL
);

-- Index for finding when last purchase/given occurred
CREATE INDEX idx_feed_inventory_last_on ON feed_inventory(last_purchase_at_utc, last_given_at_utc);