-- Migration 105: Sag Subscription Items
-- Line items for sag-based subscriptions

CREATE TABLE IF NOT EXISTS sag_subscription_items (
    id SERIAL PRIMARY KEY,
    subscription_id INTEGER NOT NULL REFERENCES sag_subscriptions(id) ON DELETE CASCADE,
    line_no INTEGER NOT NULL DEFAULT 1,
    description VARCHAR(255) NOT NULL,
    quantity DECIMAL(10,2) NOT NULL CHECK (quantity > 0),
    unit_price DECIMAL(10,2) NOT NULL CHECK (unit_price >= 0),
    line_total DECIMAL(12,2) NOT NULL CHECK (line_total >= 0),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE INDEX IF NOT EXISTS idx_sag_subscription_items_subscription
    ON sag_subscription_items(subscription_id);

CREATE INDEX IF NOT EXISTS idx_sag_subscription_items_line_no
    ON sag_subscription_items(subscription_id, line_no);

CREATE TRIGGER trigger_sag_subscription_items_updated_at
BEFORE UPDATE ON sag_subscription_items
FOR EACH ROW
EXECUTE FUNCTION update_updated_at_column();