CREATE TABLE IF NOT EXISTS `users` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `username` VARCHAR(50) NOT NULL UNIQUE,
    `password` VARCHAR(255) NOT NULL,
    `role` ENUM('regular', 'power_user', 'admin') NOT NULL DEFAULT 'regular',
    `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE IF NOT EXISTS `categories` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `name` VARCHAR(255) NOT NULL,
    `visibility` BOOLEAN NOT NULL DEFAULT TRUE,
    `display_order` INT NOT NULL DEFAULT 0
);

CREATE TABLE IF NOT EXISTS `subcategories` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `category_id` INT NOT NULL,
    `name` VARCHAR(255) NOT NULL,
    FOREIGN KEY (`category_id`) REFERENCES `categories`(`id`) ON DELETE CASCADE
);

CREATE TABLE IF NOT EXISTS `links` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `user_id` INT NOT NULL,
    `subcategory_id` INT NOT NULL,
    `title` VARCHAR(255) NOT NULL,
    `url` VARCHAR(2083) NOT NULL,
    `description` TEXT,
    `thumbnail_url` VARCHAR(2083),
    `status` ENUM('pending', 'approved', 'rejected') NOT NULL DEFAULT 'pending',
    `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (`user_id`) REFERENCES `users`(`id`),
    FOREIGN KEY (`subcategory_id`) REFERENCES `subcategories`(`id`)
);

CREATE TABLE IF NOT EXISTS `moderation_logs` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `link_id` INT NOT NULL,
    `moderator_id` INT NOT NULL,
    `action` ENUM('approved', 'rejected') NOT NULL,
    `notes` TEXT,
    `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (`link_id`) REFERENCES `links`(`id`),
    FOREIGN KEY (`moderator_id`) REFERENCES `users`(`id`)
);

CREATE TABLE IF NOT EXISTS `visits` (
    `id` INT AUTO_INCREMENT PRIMARY KEY,
    `link_id` INT,
    `user_id` INT,
    `ip_address` VARCHAR(45),
    `user_agent` TEXT,
    `visited_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    FOREIGN KEY (`link_id`) REFERENCES `links`(`id`),
    FOREIGN KEY (`user_id`) REFERENCES `users`(`id`)
);