BEGIN;

CREATE TABLE export_task (
    id                  uuid PRIMARY KEY DEFAULT gen_random_uuid(),
    public_id           uuid NOT NULL UNIQUE DEFAULT gen_random_uuid(),
    tenant_id           uuid NOT NULL REFERENCES tenant(id),
    subject_id          uuid NOT NULL,
    requested_by        uuid NOT NULL,
    scope               jsonb NOT NULL DEFAULT '{}'::jsonb CHECK (jsonb_typeof(scope)='object'),
    status              varchar(24) NOT NULL DEFAULT 'QUEUED'
                        CHECK (status IN ('QUEUED', 'RUNNING', 'READY', 'FAILED', 'EXPIRED')),
    object_ref          varchar(700),
    object_size         bigint CHECK (object_size IS NULL OR object_size >= 0),
    content_digest      char(64),
    expires_at          timestamptz,
    attempts            integer NOT NULL DEFAULT 0 CHECK (attempts >= 0),
    last_error          varchar(500),
    idempotency_key     varchar(255) NOT NULL,
    request_digest      char(64) NOT NULL,
    created_at          timestamptz NOT NULL DEFAULT now(),
    updated_at          timestamptz NOT NULL DEFAULT now(),
    completed_at        timestamptz,
    CONSTRAINT export_task_subject_tenant_fk
        FOREIGN KEY (subject_id, tenant_id) REFERENCES subject_profile (id, tenant_id),
    CONSTRAINT export_task_requester_tenant_fk
        FOREIGN KEY (requested_by, tenant_id) REFERENCES user_account (id, tenant_id),
    CONSTRAINT export_task_actor_idempotency_key
        UNIQUE (tenant_id, requested_by, idempotency_key),
    CONSTRAINT export_task_ready_fields CHECK (
        status <> 'READY' OR
        (object_ref IS NOT NULL AND object_size IS NOT NULL AND content_digest IS NOT NULL AND expires_at IS NOT NULL AND completed_at IS NOT NULL)
    )
);
CREATE INDEX export_task_subject_time_idx
    ON export_task (tenant_id, subject_id, created_at DESC, id DESC);
CREATE INDEX export_task_expiry_idx
    ON export_task (expires_at) WHERE status='READY';

COMMIT;