-- 旧会员体系 → V0~V5（可重复执行）
-- old: normal/silver/gold/diamond
-- new: V0 普通 / V1 铜卡(新增) / V2 银卡 / V3 金卡 / V4 钻石 / V5 皇冠(新增)
SET @db := DATABASE();

SET @col := (
  SELECT COUNT(1)
  FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = @db
    AND TABLE_NAME = 't_member_level'
    AND COLUMN_NAME = 'CanDowngrade'
);
SET @sql := IF(
  @col = 0,
  'ALTER TABLE `t_member_level`
    ADD COLUMN `CanDowngrade` TINYINT(1) NOT NULL DEFAULT 0 COMMENT ''V4/V5 允许逐级降级'' AFTER `ExtraDiscountRate`',
  'SELECT ''CanDowngrade already exists'' AS info'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- ---------- 把旧行升级成新编码（仅当目标 V* 还不存在）----------
UPDATE `t_member_level`
SET
  `LevelCode` = 'V0',
  `LevelName` = '普通会员',
  `MinPoints` = 0,
  `ExtraDiscountRate` = 0.00,
  `CanDowngrade` = 0,
  `Sort` = 0,
  `BenefitDesc` = '新注册 / 小单试单卖家',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0
  AND LOWER(`LevelCode`) = 'normal'
  AND NOT EXISTS (SELECT 1 FROM (SELECT 1 FROM `t_member_level` x WHERE x.`IsDeleted` = 0 AND x.`LevelCode` = 'V0') t);

UPDATE `t_member_level`
SET
  `LevelCode` = 'V2',
  `LevelName` = '银卡会员',
  `MinPoints` = 60000,
  `ExtraDiscountRate` = 0.02,
  `CanDowngrade` = 0,
  `Sort` = 2,
  `BenefitDesc` = '主力中小卖家，基础运费 98 折',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0
  AND LOWER(`LevelCode`) = 'silver'
  AND NOT EXISTS (SELECT 1 FROM (SELECT 1 FROM `t_member_level` x WHERE x.`IsDeleted` = 0 AND x.`LevelCode` = 'V2') t);

UPDATE `t_member_level`
SET
  `LevelCode` = 'V3',
  `LevelName` = '金卡会员',
  `MinPoints` = 120000,
  `ExtraDiscountRate` = 0.03,
  `CanDowngrade` = 0,
  `Sort` = 3,
  `BenefitDesc` = '优质中型卖家，基础运费 97 折；此级及以下只升不降',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0
  AND LOWER(`LevelCode`) = 'gold'
  AND NOT EXISTS (SELECT 1 FROM (SELECT 1 FROM `t_member_level` x WHERE x.`IsDeleted` = 0 AND x.`LevelCode` = 'V3') t);

UPDATE `t_member_level`
SET
  `LevelCode` = 'V4',
  `LevelName` = '钻石会员',
  `MinPoints` = 240000,
  `ExtraDiscountRate` = 0.04,
  `CanDowngrade` = 1,
  `Sort` = 4,
  `BenefitDesc` = '中大卖家，基础运费 96 折；滚动积分不足可降到金卡',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0
  AND LOWER(`LevelCode`) = 'diamond'
  AND NOT EXISTS (SELECT 1 FROM (SELECT 1 FROM `t_member_level` x WHERE x.`IsDeleted` = 0 AND x.`LevelCode` = 'V4') t);

-- ---------- 缺档则插入（铜卡、皇冠，以及未被旧行带过来的档）----------
INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V0', '普通会员', 0, 0.00, 0, 0, '新注册 / 小单试单卖家', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V0' AND `IsDeleted` = 0);

INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V1', '铜卡会员', 24000, 0.01, 0, 1, '起步稳定发货卖家，基础运费 99 折', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V1' AND `IsDeleted` = 0);

INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V2', '银卡会员', 60000, 0.02, 0, 2, '主力中小卖家，基础运费 98 折', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V2' AND `IsDeleted` = 0);

INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V3', '金卡会员', 120000, 0.03, 0, 3, '优质中型卖家，基础运费 97 折；此级及以下只升不降', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V3' AND `IsDeleted` = 0);

INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V4', '钻石会员', 240000, 0.04, 1, 4, '中大卖家，基础运费 96 折；滚动积分不足可降到金卡', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V4' AND `IsDeleted` = 0);

INSERT INTO `t_member_level`
  (`LevelCode`, `LevelName`, `MinPoints`, `ExtraDiscountRate`, `CanDowngrade`, `Sort`, `BenefitDesc`, `Status`, `IsDeleted`, `CreateTime`)
SELECT 'V5', '皇冠会员', 600000, 0.05, 1, 5, '顶级头部卖家，基础运费 95 折封顶；滚动积分不足可降到钻石', 2, 0, NOW()
WHERE NOT EXISTS (SELECT 1 FROM `t_member_level` WHERE `LevelCode` = 'V5' AND `IsDeleted` = 0);

-- ---------- 旧编码与新档并存时：客户挂到新档，旧行停用 ----------
UPDATE `t_customer` c
INNER JOIN `t_member_level` old ON old.`Id` = c.`MemberLevelId` AND old.`IsDeleted` = 0
INNER JOIN `t_member_level` canon ON canon.`IsDeleted` = 0 AND canon.`LevelCode` = CASE LOWER(old.`LevelCode`)
  WHEN 'normal' THEN 'V0'
  WHEN 'silver' THEN 'V2'
  WHEN 'gold' THEN 'V3'
  WHEN 'diamond' THEN 'V4'
  ELSE NULL
END
SET c.`MemberLevelId` = canon.`Id`, c.`UpdateTime` = NOW()
WHERE LOWER(old.`LevelCode`) IN ('normal', 'silver', 'gold', 'diamond')
  AND old.`Id` <> canon.`Id`;

UPDATE `t_member_level` old
INNER JOIN `t_member_level` canon ON canon.`IsDeleted` = 0 AND canon.`LevelCode` = CASE LOWER(old.`LevelCode`)
  WHEN 'normal' THEN 'V0'
  WHEN 'silver' THEN 'V2'
  WHEN 'gold' THEN 'V3'
  WHEN 'diamond' THEN 'V4'
  ELSE NULL
END
SET
  old.`IsDeleted` = 1,
  old.`Status` = 1,
  old.`UpdateTime` = NOW()
WHERE old.`IsDeleted` = 0
  AND LOWER(old.`LevelCode`) IN ('normal', 'silver', 'gold', 'diamond')
  AND old.`Id` <> canon.`Id`;

-- ---------- 校正 V0~V5 门槛/折扣（已占用客户的行 Id 不变）----------
UPDATE `t_member_level`
SET
  `LevelName` = '普通会员',
  `MinPoints` = 0,
  `ExtraDiscountRate` = 0.00,
  `CanDowngrade` = 0,
  `Sort` = 0,
  `BenefitDesc` = '新注册 / 小单试单卖家',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V0';

UPDATE `t_member_level`
SET
  `LevelName` = '铜卡会员',
  `MinPoints` = 24000,
  `ExtraDiscountRate` = 0.01,
  `CanDowngrade` = 0,
  `Sort` = 1,
  `BenefitDesc` = '起步稳定发货卖家，基础运费 99 折',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V1';

UPDATE `t_member_level`
SET
  `LevelName` = '银卡会员',
  `MinPoints` = 60000,
  `ExtraDiscountRate` = 0.02,
  `CanDowngrade` = 0,
  `Sort` = 2,
  `BenefitDesc` = '主力中小卖家，基础运费 98 折',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V2';

UPDATE `t_member_level`
SET
  `LevelName` = '金卡会员',
  `MinPoints` = 120000,
  `ExtraDiscountRate` = 0.03,
  `CanDowngrade` = 0,
  `Sort` = 3,
  `BenefitDesc` = '优质中型卖家，基础运费 97 折；此级及以下只升不降',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V3';

UPDATE `t_member_level`
SET
  `LevelName` = '钻石会员',
  `MinPoints` = 240000,
  `ExtraDiscountRate` = 0.04,
  `CanDowngrade` = 1,
  `Sort` = 4,
  `BenefitDesc` = '中大卖家，基础运费 96 折；滚动积分不足可降到金卡',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V4';

UPDATE `t_member_level`
SET
  `LevelName` = '皇冠会员',
  `MinPoints` = 600000,
  `ExtraDiscountRate` = 0.05,
  `CanDowngrade` = 1,
  `Sort` = 5,
  `BenefitDesc` = '顶级头部卖家，基础运费 95 折封顶；滚动积分不足可降到钻石',
  `Status` = 2,
  `UpdateTime` = NOW()
WHERE `IsDeleted` = 0 AND `LevelCode` = 'V5';