-- broker.broker_queueinstance
-- Tracks active and historical broker queue instances.

CREATE TABLE IF NOT EXISTS broker.broker_queueinstance (
    id_broker_queueinstance BIGSERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    hostname VARCHAR(255) NOT NULL,
    pid INTEGER NOT NULL,
    version VARCHAR(50) NOT NULL,
    status VARCHAR(20) NOT NULL DEFAULT 'active',
    started_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
    last_ping_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
    shutdown_at TIMESTAMP WITH TIME ZONE,
    queue_count INTEGER NOT NULL DEFAULT 0,
    jobs_handled BIGINT NOT NULL DEFAULT 0,

    CONSTRAINT broker_queueinstance_status_check CHECK (status IN ('active', 'inactive', 'shutdown'))
);

CREATE INDEX IF NOT EXISTS idx_broker_queueinstance_status ON broker.broker_queueinstance(status);
CREATE INDEX IF NOT EXISTS idx_broker_queueinstance_hostname ON broker.broker_queueinstance(hostname);
CREATE INDEX IF NOT EXISTS idx_broker_queueinstance_last_ping ON broker.broker_queueinstance(last_ping_at);

COMMENT ON TABLE broker.broker_queueinstance IS 'Tracks broker queue instances (active and historical). Single-active-instance-per-name is enforced via a pg_try_advisory_lock in broker_register_instance, not by this status column, which is observational only.';
COMMENT ON COLUMN broker.broker_queueinstance.status IS 'Observational status: active, inactive, or shutdown. Ownership is enforced via advisory lock, not by reading this column.';