-- Alter existing biz_rule to product/country/customer dimension storage
SET NAMES utf8mb4;

-- add new columns if missing
SET @sql := (
  SELECT IF(
    EXISTS(SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND column_name = 'product_code'),
    'SELECT 1',
    'ALTER TABLE biz_rule ADD COLUMN product_code varchar(64) DEFAULT NULL COMMENT ''产品代码（空=全部）'' AFTER rule_type'
  )
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;

SET @sql := (
  SELECT IF(
    EXISTS(SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND column_name = 'country_code'),
    'SELECT 1',
    'ALTER TABLE biz_rule ADD COLUMN country_code varchar(10) DEFAULT NULL COMMENT ''国家ISO2（空=全部）'' AFTER product_code'
  )
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;

SET @sql := (
  SELECT IF(
    EXISTS(SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND column_name = 'customer_code'),
    'SELECT 1',
    'ALTER TABLE biz_rule ADD COLUMN customer_code varchar(64) DEFAULT NULL COMMENT ''客户代码（空=全部）'' AFTER country_code'
  )
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;

-- migrate CSV rows: take first token only as best-effort (manual fix may be needed)
UPDATE biz_rule
   SET product_code = NULLIF(TRIM(SUBSTRING_INDEX(REPLACE(IFNULL(product_codes,''), ' ', ''), ',', 1)), ''),
       country_code = NULLIF(TRIM(SUBSTRING_INDEX(REPLACE(IFNULL(country_codes,''), ' ', ''), ',', 1)), ''),
       customer_code = NULLIF(TRIM(SUBSTRING_INDEX(REPLACE(IFNULL(customer_codes,''), ' ', ''), ',', 1)), '')
 WHERE product_code IS NULL
   AND EXISTS(SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND column_name = 'product_codes');

-- drop old CSV columns if present
SET @sql := (
  SELECT IF(
    EXISTS(SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND column_name = 'product_codes'),
    'ALTER TABLE biz_rule DROP COLUMN product_codes, DROP COLUMN country_codes, DROP COLUMN customer_codes',
    'SELECT 1'
  )
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;

SET @sql := (
  SELECT IF(
    EXISTS(SELECT 1 FROM information_schema.statistics WHERE table_schema = DATABASE() AND table_name = 'biz_rule' AND index_name = 'idx_biz_rule_dim'),
    'SELECT 1',
    'ALTER TABLE biz_rule ADD KEY idx_biz_rule_dim (product_code, country_code, customer_code)'
  )
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;