foxhunt/migrations/046_rollback_regime_detection.sql

-- ================================================================================================
-- Migration 046: Emergency Rollback for Wave D Regime Detection
-- Purpose: Quick rollback mechanism for production incidents
-- Author: Agent R1 - Rollback & Disaster Recovery Specialist
-- Date: 2025-10-19
-- ================================================================================================
--
-- USAGE:
--   sqlx migrate revert
--
-- CAUTION:
--   This migration removes ALL Wave D regime detection data and infrastructure.
--   Use only for critical production incidents requiring immediate rollback.
--   Data loss: regime_states, regime_transitions, adaptive_strategy_metrics
--
-- ================================================================================================

-- Step 1: Revoke permissions (fail-safe)
DO $$
BEGIN
    REVOKE EXECUTE ON FUNCTION get_regime_performance(TEXT, INTEGER) FROM foxhunt;
    REVOKE EXECUTE ON FUNCTION get_regime_transition_matrix(TEXT, INTEGER) FROM foxhunt;
    REVOKE EXECUTE ON FUNCTION get_latest_regime(TEXT) FROM foxhunt;
EXCEPTION
    WHEN undefined_function THEN NULL;
    WHEN undefined_object THEN NULL;
END $$;

DO $$
BEGIN
    REVOKE USAGE, SELECT ON SEQUENCE adaptive_strategy_metrics_id_seq FROM foxhunt;
    REVOKE USAGE, SELECT ON SEQUENCE regime_transitions_id_seq FROM foxhunt;
    REVOKE USAGE, SELECT ON SEQUENCE regime_states_id_seq FROM foxhunt;
EXCEPTION
    WHEN undefined_table THEN NULL;
END $$;

DO $$
BEGIN
    REVOKE SELECT, INSERT, UPDATE ON adaptive_strategy_metrics FROM foxhunt;
    REVOKE SELECT, INSERT ON regime_transitions FROM foxhunt;
    REVOKE SELECT, INSERT, UPDATE ON regime_states FROM foxhunt;
EXCEPTION
    WHEN undefined_table THEN NULL;
END $$;

-- Step 2: Drop functions (in reverse order of dependencies)
DROP FUNCTION IF EXISTS get_regime_performance(TEXT, INTEGER) CASCADE;
DROP FUNCTION IF EXISTS get_regime_transition_matrix(TEXT, INTEGER) CASCADE;
DROP FUNCTION IF EXISTS get_latest_regime(TEXT) CASCADE;

-- Step 3: Drop tables (in reverse order of creation, CASCADE to remove dependencies)
DROP TABLE IF EXISTS adaptive_strategy_metrics CASCADE;
DROP TABLE IF EXISTS regime_transitions CASCADE;
DROP TABLE IF EXISTS regime_states CASCADE;

-- Step 4: Verify rollback completion
DO $$
DECLARE
    table_count INTEGER;
    function_count INTEGER;
BEGIN
    -- Check for remaining tables
    SELECT COUNT(*) INTO table_count
    FROM information_schema.tables
    WHERE table_schema = 'public'
      AND table_name IN ('regime_states', 'regime_transitions', 'adaptive_strategy_metrics');

    IF table_count > 0 THEN
        RAISE EXCEPTION 'Rollback failed: % Wave D tables still exist', table_count;
    END IF;

    -- Check for remaining functions
    SELECT COUNT(*) INTO function_count
    FROM information_schema.routines
    WHERE routine_schema = 'public'
      AND routine_name IN ('get_latest_regime', 'get_regime_transition_matrix', 'get_regime_performance');

    IF function_count > 0 THEN
        RAISE EXCEPTION 'Rollback failed: % Wave D functions still exist', function_count;
    END IF;

    RAISE NOTICE 'Wave D rollback completed successfully: All regime detection tables and functions removed';
END $$;

-- ================================================================================================
-- END MIGRATION 046
-- ================================================================================================