CREATE TABLE IF NOT EXISTS users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(255) NOT NULL UNIQUE,
  email VARCHAR(255) NOT NULL UNIQUE,
  password VARCHAR(255) NOT NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE TABLE IF NOT EXISTS sellers (
  id INT AUTO_INCREMENT PRIMARY KEY,
  user_id INT,
  store_name VARCHAR(255) NOT NULL,
  business_email VARCHAR(255) NOT NULL UNIQUE,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (user_id) REFERENCES users(id)
);

CREATE TABLE IF NOT EXISTS categories (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(255) NOT NULL,
  image_url VARCHAR(255)
);

CREATE TABLE IF NOT EXISTS products (
  id INT AUTO_INCREMENT PRIMARY KEY,
  seller_id INT,
  category_id INT,
  name VARCHAR(255) NOT NULL,
  description TEXT,
  price DECIMAL(10, 2) NOT NULL,
  image_url VARCHAR(255),
  stock_quantity INT NOT NULL DEFAULT 0,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  FOREIGN KEY (seller_id) REFERENCES sellers(id),
  FOREIGN KEY (category_id) REFERENCES categories(id)
);