-- Migration: add iKhokha / provider metadata to payments table
-- Migration: add iKhokha / provider metadata to payments table
-- Compatible with MySQL versions that do not support `ADD COLUMN IF NOT EXISTS`.
-- Run on staging first. Make a DB backup before running on production.

DELIMITER $$
CREATE PROCEDURE add_payment_columns_if_missing()
BEGIN
  -- provider
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'provider') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `provider` VARCHAR(50) NULL AFTER `status`;
  END IF;

  -- provider_payment_id
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'provider_payment_id') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `provider_payment_id` VARCHAR(128) NULL AFTER `provider`;
  END IF;

  -- payment_link
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'payment_link') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `payment_link` VARCHAR(512) NULL AFTER `provider_payment_id`;
  END IF;

  -- provider_status
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'provider_status') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `provider_status` VARCHAR(50) NULL AFTER `payment_link`;
  END IF;

  -- provider_response (JSON)
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'provider_response') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `provider_response` JSON NULL AFTER `provider_status`;
  END IF;

  -- booking_id
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND COLUMN_NAME = 'booking_id') = 0 THEN
    ALTER TABLE `payments` ADD COLUMN `booking_id` INT NULL AFTER `user_id`;
  END IF;

  -- index idx_provider_payment_id
  IF (SELECT COUNT(*) FROM INFORMATION_SCHEMA.STATISTICS
      WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'payments' AND INDEX_NAME = 'idx_provider_payment_id') = 0 THEN
    ALTER TABLE `payments` ADD INDEX `idx_provider_payment_id` (`provider_payment_id`(128));
  END IF;
END$$
DELIMITER ;

CALL add_payment_columns_if_missing();
DROP PROCEDURE IF EXISTS add_payment_columns_if_missing;

-- Notes:
-- 1) This script creates a short stored procedure which performs existence checks
--    against INFORMATION_SCHEMA before applying each ALTER TABLE. Run in the
--    MySQL client or via your migration tool. It avoids syntax not supported on
--    older MySQL versions.
-- 2) Test on staging and make a DB dump before running on production.