-- +goose Up

-- 退款补偿重试字段：限制失败补偿的自动重试次数，并支持退避。
SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'retry_count') = 0,
  'ALTER TABLE payment_orders ADD COLUMN retry_count INT NOT NULL DEFAULT 0 COMMENT ''自动补偿重试次数'' AFTER raw_response',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'last_retry_at') = 0,
  'ALTER TABLE payment_orders ADD COLUMN last_retry_at DATETIME NULL COMMENT ''最近自动补偿重试时间'' AFTER retry_count',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'next_retry_at') = 0,
  'ALTER TABLE payment_orders ADD COLUMN next_retry_at DATETIME NULL COMMENT ''下次允许自动补偿重试时间'' AFTER last_retry_at',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- 退款补偿扫描索引：按业务类型、状态、下次重试时间批量捞取待同步退款单。
SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.STATISTICS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND INDEX_NAME = 'idx_payment_orders_refund_retry') = 0,
  'CREATE INDEX idx_payment_orders_refund_retry ON payment_orders (biz_type, status, next_retry_at, updated_at, id)',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

-- +goose Down

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.STATISTICS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND INDEX_NAME = 'idx_payment_orders_refund_retry') > 0,
  'ALTER TABLE payment_orders DROP INDEX idx_payment_orders_refund_retry',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'next_retry_at') > 0,
  'ALTER TABLE payment_orders DROP COLUMN next_retry_at',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'last_retry_at') > 0,
  'ALTER TABLE payment_orders DROP COLUMN last_retry_at',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

SET @sql = IF(
  (SELECT COUNT(*) FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payment_orders' AND COLUMN_NAME = 'retry_count') > 0,
  'ALTER TABLE payment_orders DROP COLUMN retry_count',
  'SELECT 1'
);
PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;