-- Delayed order emails table

CREATE TYPE delayed_orders_email_type AS ENUM ('automatic', 'manual');
CREATE TYPE delayed_orders_email_status as ENUM ('created', 'sent', 'error', 'blocked');

CREATE TABLE delayed_orders_email (
    id SERIAL PRIMARY KEY,
    order_id int REFERENCES orders (id) NOT NULL,
    type delayed_orders_email_type NOT NULL,
    status delayed_orders_email_status NOT NULL,
    date timestamp with time zone DEFAULT now()
);

-- This creates a partial unique constraint.
-- It enforces max one automatic email; allows multiple manual emails; enables blocking automatic email.
CREATE UNIQUE INDEX unique_automatic_delayed_orders_emails ON delayed_orders_email (order_id) WHERE (type = 'automatic');