-- =============================================
-- 角色权限迁移脚本（简化版，不使用存储过程）
-- 将 yz_role_menus 表中的权限数据迁移到 yz_roles 表的 menu_ids 字段（JSON数组）
-- =============================================

SET NAMES utf8mb4;

-- =============================================
-- 步骤1: 在 yz_roles 表中添加 menu_ids 字段（JSON类型存储菜单ID数组）
-- =============================================

-- 检查字段是否已存在，如果不存在则添加
SET @exist := (SELECT COUNT(*) FROM information_schema.columns
               WHERE table_schema = DATABASE()
               AND table_name = 'yz_roles'
               AND column_name = 'menu_ids');

SET @sqlstmt := IF(@exist = 0,
                   'ALTER TABLE yz_roles ADD COLUMN menu_ids JSON NULL COMMENT ''菜单权限ID数组，JSON格式存储'' AFTER description',
                   'SELECT ''字段 menu_ids 已存在，跳过添加'' AS message');

PREPARE stmt FROM @sqlstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- =============================================
-- 步骤2: 从 yz_role_menus 表迁移数据到 yz_roles.menu_ids
-- =============================================

-- 检查 yz_role_menus 表是否存在
SET @table_exists := (SELECT COUNT(*) FROM information_schema.tables
                      WHERE table_schema = DATABASE()
                      AND table_name = 'yz_role_menus');

-- 如果表存在，执行迁移
-- 注意：需要分步执行，因为PREPARE不能执行多语句

-- 2.1 创建临时表存储每个角色的菜单ID数组
-- 使用 GROUP_CONCAT 和 CONCAT 来构建JSON数组（兼容性更好）
-- 处理 NULL 情况：如果 GROUP_CONCAT 返回 NULL，则使用空数组 '[]'
SET @sqlstmt := IF(@table_exists > 0,
                   'CREATE TEMPORARY TABLE temp_role_menu_ids AS
                    SELECT 
                        role_id,
                        IFNULL(CONCAT(''['', GROUP_CONCAT(menu_id ORDER BY menu_id SEPARATOR '',''), '']''), ''[]'') as menu_ids_json
                    FROM yz_role_menus
                    GROUP BY role_id',
                   'SELECT ''表 yz_role_menus 不存在，跳过数据迁移'' AS message');

PREPARE stmt FROM @sqlstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 2.2 更新 yz_roles 表的 menu_ids 字段
-- 将字符串转换为 JSON 类型
SET @sqlstmt := IF(@table_exists > 0,
                   'UPDATE yz_roles r
                    INNER JOIN temp_role_menu_ids t ON r.role_id = t.role_id
                    SET r.menu_ids = CAST(t.menu_ids_json AS JSON)',
                   'SELECT ''跳过更新'' AS message');

PREPARE stmt FROM @sqlstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 2.3 删除临时表
SET @sqlstmt := IF(@table_exists > 0,
                   'DROP TEMPORARY TABLE IF EXISTS temp_role_menu_ids',
                   'SELECT ''跳过删除临时表'' AS message');

PREPARE stmt FROM @sqlstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 2.4 对于没有权限的角色，确保设置为空数组（如果还没有设置）
-- 使用 CAST 将字符串转换为 JSON 类型
UPDATE yz_roles 
SET menu_ids = CAST('[]' AS JSON)
WHERE menu_ids IS NULL;

-- =============================================
-- 步骤3: 验证迁移结果
-- =============================================

SELECT 
    r.role_id,
    r.role_name,
    r.menu_ids,
    JSON_LENGTH(COALESCE(r.menu_ids, CAST('[]' AS JSON))) as menu_count,
    (SELECT COUNT(*) FROM yz_role_menus WHERE role_id = r.role_id) as old_count
FROM yz_roles r
WHERE r.delete_time IS NULL
ORDER BY r.role_id;

-- =============================================
-- 步骤4: 备份旧表（可选，建议先备份）
-- =============================================

-- 检查 yz_role_menus 表是否存在
SET @table_exists := (SELECT COUNT(*) FROM information_schema.tables
                      WHERE table_schema = DATABASE()
                      AND table_name = 'yz_role_menus');

-- 检查备份表是否已存在
SET @backup_exists := (SELECT COUNT(*) FROM information_schema.tables
                       WHERE table_schema = DATABASE()
                       AND table_name = 'yz_role_menus_backup');

-- 如果原表存在且备份表不存在，则创建备份
SET @sqlstmt := IF(@table_exists > 0 AND @backup_exists = 0,
                   'CREATE TABLE yz_role_menus_backup AS SELECT * FROM yz_role_menus',
                   IF(@backup_exists > 0,
                      'SELECT ''备份表 yz_role_menus_backup 已存在，跳过备份'' AS message',
                      'SELECT ''表 yz_role_menus 不存在，无需备份'' AS message'));

PREPARE stmt FROM @sqlstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- =============================================
-- 注意：迁移完成后，需要确认数据正确，然后可以删除 yz_role_menus 表
-- 删除命令：DROP TABLE IF EXISTS yz_role_menus;
-- =============================================