CREATE TABLE IF NOT EXISTS `messages` (
  `id` INT AUTO_INCREMENT PRIMARY KEY,
  `sender_id` INT NOT NULL,
  `receiver_id` INT, -- For private messages
  `group_id` INT, -- For group messages
  `message` TEXT NOT NULL,
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (sender_id) REFERENCES users(id),
  FOREIGN KEY (receiver_id) REFERENCES users(id)
  -- FOREIGN KEY (group_id) REFERENCES chat_groups(id) -- This will be added later to avoid circular dependency
);

CREATE TABLE IF NOT EXISTS `chat_groups` (
  `id` INT AUTO_INCREMENT PRIMARY KEY,
  `name` VARCHAR(255) NOT NULL,
  `creator_id` INT NOT NULL,
  `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (creator_id) REFERENCES users(id)
);

CREATE TABLE IF NOT EXISTS `chat_group_members` (
  `id` INT AUTO_INCREMENT PRIMARY KEY,
  `group_id` INT NOT NULL,
  `user_id` INT NOT NULL,
  `role` ENUM('member', 'admin') NOT NULL DEFAULT 'member',
  FOREIGN KEY (group_id) REFERENCES chat_groups(id),
  FOREIGN KEY (user_id) REFERENCES users(id)
);

ALTER TABLE `messages` ADD CONSTRAINT `fk_messages_group_id` FOREIGN KEY (`group_id`) REFERENCES `chat_groups`(`id`);