CREATE TABLE IF NOT EXISTS maintenance_policy (
    id TEXT PRIMARY KEY,
    name TEXT NOT NULL,
    table_name TEXT NOT NULL,
    condition_sql TEXT NOT NULL DEFAULT 'true',
    retention_period_sec INTEGER,
    max_rows INTEGER,
    vacuum_strategy TEXT NOT NULL DEFAULT 'none',
    schedule_cron TEXT NOT NULL,
    enabled BOOLEAN NOT NULL DEFAULT true,
    dry_run_enabled BOOLEAN NOT NULL DEFAULT false,
    last_run_at TIMESTAMPTZ,
    last_status TEXT,
    last_error TEXT,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT maintenance_policy_name_chk CHECK (length(trim(name)) > 0),
    CONSTRAINT maintenance_policy_table_name_chk CHECK (length(trim(table_name)) > 0),
    CONSTRAINT maintenance_policy_vacuum_strategy_chk CHECK (
        vacuum_strategy IN ('none', 'vacuum', 'analyze', 'vacuum_analyze', 'reindex')
    )
);

CREATE INDEX IF NOT EXISTS idx_maintenance_policy_enabled
    ON maintenance_policy (enabled);

CREATE TABLE IF NOT EXISTS maintenance_policy_config_audit (
    id TEXT PRIMARY KEY,
    policy_id TEXT,
    actor_prefix TEXT NOT NULL,
    action TEXT NOT NULL,
    before_json JSONB,
    after_json JSONB,
    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT maintenance_policy_config_audit_action_chk CHECK (
        action IN ('create', 'update', 'delete')
    )
);

CREATE INDEX IF NOT EXISTS idx_maintenance_policy_config_audit_created
    ON maintenance_policy_config_audit (created_at DESC);

ALTER TABLE postgres_maintenance_audit
    ADD COLUMN IF NOT EXISTS policy_id TEXT REFERENCES maintenance_policy (id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS idx_postgres_maintenance_audit_policy
    ON postgres_maintenance_audit (policy_id);