-- Packing lists for shipping finished products
CREATE TABLE IF NOT EXISTS packing_lists (
  id SERIAL PRIMARY KEY,
  packing_list_number VARCHAR(100) UNIQUE NOT NULL,
  purchase_order_id INTEGER NOT NULL REFERENCES purchase_orders(id),
  customer_id INTEGER NOT NULL REFERENCES customers(id),
  product_id INTEGER NOT NULL,
  quantity_shipped INTEGER NOT NULL DEFAULT 0,
  status VARCHAR(20) NOT NULL DEFAULT 'draft' CHECK (status IN ('draft', 'finalized')),
  shipped_date DATE,
  notes TEXT,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- Serial numbers for each packing list
CREATE TABLE IF NOT EXISTS packing_list_serials (
  id SERIAL PRIMARY KEY,
  packing_list_id INTEGER NOT NULL REFERENCES packing_lists(id) ON DELETE CASCADE,
  serial_number VARCHAR(200) NOT NULL,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_packing_lists_po ON packing_lists(purchase_order_id);
CREATE INDEX IF NOT EXISTS idx_packing_lists_customer ON packing_lists(customer_id);
CREATE INDEX IF NOT EXISTS idx_packing_list_serials_pl ON packing_list_serials(packing_list_id);
CREATE INDEX IF NOT EXISTS idx_packing_list_serials_sn ON packing_list_serials(serial_number);

-- Add shipped_quantity column to purchase_order_items to track how many units have been shipped
ALTER TABLE purchase_order_items ADD COLUMN IF NOT EXISTS shipped_quantity INTEGER NOT NULL DEFAULT 0;