-- name: CreateScheduledChange :one
INSERT INTO core.subscription_scheduled_changes
    (subscription_id, change_type, target_price_id, target_quantity, effective_at, effective_trigger, credit_disposition)
VALUES ($1, $2, $3, $4, $5, $6, $7)
RETURNING *;

-- name: GetScheduledChangeByID :one
SELECT * FROM core.subscription_scheduled_changes
WHERE scheduled_change_id = $1;

-- name: ListActiveScheduledChangesBySubscription :many
SELECT * FROM core.subscription_scheduled_changes
WHERE subscription_id = $1 AND status = 'scheduled'
ORDER BY effective_at ASC;

-- name: ListDueScheduledChanges :many
-- Sweeper backstop: due, not-yet-fired rows. Concurrency safety comes from the
-- per-row claim (MarkScheduledChangeApplied), not row locking, so a plain read
-- is sufficient.
SELECT * FROM core.subscription_scheduled_changes
WHERE status = 'scheduled' AND effective_at <= NOW()
ORDER BY effective_at ASC;

-- name: MarkScheduledChangeApplied :one
-- Idempotency guard / claim: the status transition scheduled->applied is the
-- claim. A second firer (webhook vs sweeper) gets sql.ErrNoRows and no-ops.
UPDATE core.subscription_scheduled_changes
SET status = 'applied'
WHERE scheduled_change_id = $1 AND status = 'scheduled'
RETURNING *;

-- name: ApplyScheduledChangesForSubscription :exec
-- Webhook-primary closeout: when a subscription actually ends (Stripe fires
-- customer.subscription.deleted at period end), mark its still-pending scheduled
-- changes applied so the intent ledger reflects what happened.
UPDATE core.subscription_scheduled_changes
SET status = 'applied'
WHERE subscription_id = $1 AND status = 'scheduled';

-- name: CancelScheduledChange :one
UPDATE core.subscription_scheduled_changes
SET status = 'canceled'
WHERE scheduled_change_id = $1 AND status = 'scheduled'
RETURNING *;

-- name: SupersedeActiveScheduledChanges :exec
-- A new scheduled change (or an immediate action) supersedes any still-pending
-- intent on the same subscription.
UPDATE core.subscription_scheduled_changes
SET status = 'superseded'
WHERE subscription_id = $1 AND status = 'scheduled';