-- 仅用于本地环境：为 IM 业务表补充 tenant_id 字段。
--
-- 本脚本只修改表结构并回填现有数据，不修改索引、唯一约束或应用代码，
-- 也不会启用多商户共库能力。

USE `tinode`;

DELIMITER $$

DROP PROCEDURE IF EXISTS add_im_tenant_columns$$
CREATE PROCEDURE add_im_tenant_columns(IN target_schema VARCHAR(64), IN default_tenant_id BIGINT)
BEGIN
    DECLARE done INT DEFAULT 0;
    DECLARE target_table VARCHAR(128);
    DECLARE has_id INT DEFAULT 0;
    DECLARE table_cursor CURSOR FOR
        SELECT t.table_name
        FROM information_schema.tables t
        WHERE t.table_schema = target_schema
          AND t.table_type = 'BASE TABLE'
          AND t.table_name LIKE 'im\_%'
          AND NOT EXISTS (
              SELECT 1
              FROM information_schema.columns c
              WHERE c.table_schema = t.table_schema
                AND c.table_name = t.table_name
                AND c.column_name = 'tenant_id'
          );
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

    OPEN table_cursor;
    table_loop: LOOP
        FETCH table_cursor INTO target_table;
        IF done = 1 THEN
            LEAVE table_loop;
        END IF;

        SELECT COUNT(*) INTO has_id
        FROM information_schema.columns
        WHERE table_schema = target_schema
          AND table_name = target_table
          AND column_name = 'id';

        SET @position_sql = IF(has_id > 0, ' AFTER `id`', ' FIRST');
        SET @alter_sql = CONCAT(
            'ALTER TABLE `', target_schema, '`.`', target_table,
            '` ADD COLUMN `tenant_id` BIGINT NOT NULL DEFAULT ',
            default_tenant_id,
            ' COMMENT ''租户ID''',
            @position_sql
        );
        PREPARE alter_stmt FROM @alter_sql;
        EXECUTE alter_stmt;
        DEALLOCATE PREPARE alter_stmt;
    END LOOP;
    CLOSE table_cursor;
END$$

DELIMITER ;

-- 本地默认业务库，现有数据归属 tenant_id=1。
CALL add_im_tenant_columns('tinode', 1);

-- 本地独立业务库，现有数据归属 tenant_id=2。
CALL add_im_tenant_columns('meeting_im', 2);

DROP PROCEDURE IF EXISTS add_im_tenant_columns;

-- 验证：以下结果中 missing_count 应全部为 0。
SELECT 'tinode' AS db_name, COUNT(*) AS missing_count
FROM information_schema.tables t
WHERE t.table_schema = 'tinode'
  AND t.table_type = 'BASE TABLE'
  AND t.table_name LIKE 'im\_%'
  AND NOT EXISTS (
      SELECT 1 FROM information_schema.columns c
      WHERE c.table_schema = t.table_schema
        AND c.table_name = t.table_name
        AND c.column_name = 'tenant_id'
  )
UNION ALL
SELECT 'meeting_im', COUNT(*)
FROM information_schema.tables t
WHERE t.table_schema = 'meeting_im'
  AND t.table_type = 'BASE TABLE'
  AND t.table_name LIKE 'im\_%'
  AND NOT EXISTS (
      SELECT 1 FROM information_schema.columns c
      WHERE c.table_schema = t.table_schema
        AND c.table_name = t.table_name
        AND c.column_name = 'tenant_id'
  );