-- 订单异常事件表：补齐 Handler* / ConcurrencyStamp（幂等；列已存在则自动跳过）
-- 修复：Unknown column 'HandlerNames' / 'ConcurrencyStamp' in 'field list'
-- MySQL 5.7+ / 8.0

SET @db := DATABASE();

-- HandlerNames
SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'HandlerNames'
);
SET @sql := IF(
  @col = 0,
  'ALTER TABLE `t_order_exception_event` ADD COLUMN `HandlerNames` VARCHAR(256) NULL COMMENT ''处理人快照''',
  'SELECT ''skip HandlerNames'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- HandlerType
SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'HandlerType'
);
SET @sql := IF(
  @col = 0,
  'ALTER TABLE `t_order_exception_event` ADD COLUMN `HandlerType` VARCHAR(16) NULL COMMENT ''处理人类型''',
  'SELECT ''skip HandlerType'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- HandlerUserId
SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'HandlerUserId'
);
SET @sql := IF(
  @col = 0,
  'ALTER TABLE `t_order_exception_event` ADD COLUMN `HandlerUserId` INT NULL COMMENT ''处理人用户Id（customer 时为订单客户账号）''',
  'SELECT ''skip HandlerUserId'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- ConcurrencyStamp（AggregateRoot 并发戳；避免 DEFAULT(UUID()) 触发 1674 复制不安全）
SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'ConcurrencyStamp'
);
SET @sql := IF(
  @col = 0,
  'ALTER TABLE `t_order_exception_event` ADD COLUMN `ConcurrencyStamp` CHAR(36) NULL COMMENT ''并发戳''',
  'SELECT ''skip ConcurrencyStamp add'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'ConcurrencyStamp'
);
SET @sql := IF(
  @col > 0,
  'UPDATE `t_order_exception_event`
     SET `ConcurrencyStamp` = LOWER(CONCAT(
       LPAD(HEX(`Id`), 8, ''0''),
       ''-0000-4000-8000-'',
       LPAD(HEX(`Id` * 9973), 12, ''0'')
     ))
   WHERE `ConcurrencyStamp` IS NULL OR `ConcurrencyStamp` = ''''',
  'SELECT ''skip ConcurrencyStamp backfill'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @col := (
  SELECT COUNT(*)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'ConcurrencyStamp'
);
SET @isNullable := (
  SELECT IFNULL(MAX(CASE WHEN IS_NULLABLE = 'YES' THEN 1 ELSE 0 END), 0)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_order_exception_event'
    AND COLUMN_NAME = 'ConcurrencyStamp'
);
SET @sql := IF(
  @col > 0 AND @isNullable = 1,
  'ALTER TABLE `t_order_exception_event` MODIFY COLUMN `ConcurrencyStamp` CHAR(36) NOT NULL COMMENT ''并发戳''',
  'SELECT ''skip ConcurrencyStamp not null'' AS msg'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;