-- name: UpsertBoundaryUsageStats :one
-- Upserts boundary usage statistics for a replica. On INSERT (new period), uses
-- delta values for unique counts (only data since last flush). On UPDATE, uses
-- cumulative values for unique counts (accurate period totals). Request counts
-- are always deltas, accumulated in DB. Returns true if insert, false if update.
INSERT INTO boundary_usage_stats (
    replica_id,
    unique_workspaces_count,
    unique_users_count,
    allowed_requests,
    denied_requests,
    window_start,
    updated_at
) VALUES (
    @replica_id,
    @unique_workspaces_delta,
    @unique_users_delta,
    @allowed_requests,
    @denied_requests,
    NOW(),
    NOW()
) ON CONFLICT (replica_id) DO UPDATE SET
    unique_workspaces_count = @unique_workspaces_count,
    unique_users_count = @unique_users_count,
    allowed_requests = boundary_usage_stats.allowed_requests + EXCLUDED.allowed_requests,
    denied_requests = boundary_usage_stats.denied_requests + EXCLUDED.denied_requests,
    updated_at = NOW()
RETURNING (xmax = 0) AS new_period;

-- name: GetAndResetBoundaryUsageSummary :one
-- Atomic read+delete prevents replicas that flush between a separate read and
-- reset from having their data deleted before the next snapshot. Uses a common
-- table expression with DELETE...RETURNING so the rows we sum are exactly the
-- rows we delete. Stale rows are excluded from the sum but still deleted.
WITH deleted AS (
    DELETE FROM boundary_usage_stats
    RETURNING *
)
SELECT
    COALESCE(SUM(unique_workspaces_count) FILTER (
        WHERE window_start >= NOW() - (@max_staleness_ms::bigint || ' ms')::interval
    ), 0)::bigint AS unique_workspaces,
    COALESCE(SUM(unique_users_count) FILTER (
        WHERE window_start >= NOW() - (@max_staleness_ms::bigint || ' ms')::interval
    ), 0)::bigint AS unique_users,
    COALESCE(SUM(allowed_requests) FILTER (
        WHERE window_start >= NOW() - (@max_staleness_ms::bigint || ' ms')::interval
    ), 0)::bigint AS allowed_requests,
    COALESCE(SUM(denied_requests) FILTER (
        WHERE window_start >= NOW() - (@max_staleness_ms::bigint || ' ms')::interval
    ), 0)::bigint AS denied_requests
FROM deleted;