-- Unique index on public_token for fast lookups of public iCal feeds
CREATE UNIQUE INDEX idx_calendars_public_token ON calendars (public_token) WHERE public_token IS NOT NULL;

-- Track calendars imported from external iCal URLs
CREATE TABLE calendar_subscriptions (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    calendar_id UUID NOT NULL REFERENCES calendars(id),
    source_url TEXT NOT NULL,
    last_synced_at TIMESTAMPTZ,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX idx_calendar_subscriptions_calendar_id ON calendar_subscriptions (calendar_id);