-- Block F — Stripe subscriptions. One row per Stripe customer + (optional)
-- active subscription. Free-tier hosts never get a row; their tier is
-- inferred at read time.

CREATE TABLE IF NOT EXISTS subscriptions (
    id                       UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    user_id                  UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    stripe_customer_id       TEXT NOT NULL,
    stripe_subscription_id   TEXT,
    tier                     TEXT NOT NULL CHECK (tier IN ('free','pro','business')),
    status                   TEXT NOT NULL CHECK (status IN ('active','past_due','canceled','incomplete','trialing','unpaid')),
    current_period_end       TIMESTAMPTZ,
    cancel_at_period_end     BOOLEAN NOT NULL DEFAULT FALSE,
    created_at               TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at               TIMESTAMPTZ NOT NULL DEFAULT now()
);

-- A user may have at most one *granting* subscription at a time. We
-- include trialing + past_due because those still convey access (past_due
-- is the grace period before Stripe gives up on the card).
CREATE UNIQUE INDEX IF NOT EXISTS uniq_subscriptions_active_user
    ON subscriptions(user_id)
    WHERE status IN ('active','past_due','trialing');

CREATE INDEX IF NOT EXISTS idx_subscriptions_customer
    ON subscriptions(stripe_customer_id);

CREATE INDEX IF NOT EXISTS idx_subscriptions_subscription
    ON subscriptions(stripe_subscription_id)
    WHERE stripe_subscription_id IS NOT NULL;