-- Restaurant Database Management System
--
-- Instructions:
-- 1. Create all required tables.
-- 2. Design appropriate PRIMARY KEY and FOREIGN KEY relationships.
-- 3. Add suitable constraints based on the requirements.
-- 4. Insert initial mock data.
-- 5. Insert at least 3 menu items.
-- 6. The script should be executable from start to finish without errors.


-- =======================================================
-- USER TABLE
-- =======================================================
--
-- Represents customers using the system.
--
-- Required information:
-- - Unique identifier
-- - Username
-- - Password
-- - Email (optional)
--
-- Requirements:
-- - Each user must have a unique identifier.
-- - Usernames must be unique.
-- - Username and password are required.
-- - Passwords should not be stored in plain text.
--
-- CREATE TABLE ...

CREATE TABLE users(
  id SERIAL PRIMARY KEY,
  username TEXT UNIQUE NOT NULL,
  password VARCHAR(250) NOT NULL,
  email VARCHAR(100)
);


-- =======================================================
-- MENU ITEM TABLE
-- =======================================================
--
-- Represents available food and drink items.
--
-- Required information:
-- - Unique identifier
-- - Name
-- - Description (optional)
-- - Price
-- - Category (optional)
--
-- Requirements:
-- - Each menu item must have a unique identifier.
-- - Name is required.
-- - Price must always be positive.
--
-- CREATE TABLE ...

CREATE TABLE menu_items(
     id SERIAL PRIMARY KEY,
     name VARCHAR(100) NOT NULL,
     description TEXT,
     price DECIMAL(10, 2) NOT NULL CHECK ( price > 0 ),
     category VARCHAR(100)
);

-- =======================================================
-- ORDER TABLE
-- =======================================================
--
-- Represents orders placed by customers.
--
-- Required information:
-- - Unique identifier
-- - Reference to customer
-- - Creation date and time
-- - Total price
--
-- Requirements:
-- - Each order must belong to exactly one user.
-- - A user can have multiple orders.
-- - The relationship between User and Order must be implemented.
--
-- Note:
-- Avoid using reserved SQL keywords as table names.
-- Consider using a name such as "orders" or "customer_orders".
--
-- CREATE TABLE ...

CREATE TABLE orders (
    id SERIAL PRIMARY KEY,
    user_id INT NOT NULL REFERENCES users(id),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    total_price DECIMAL(10, 2) DEFAULT 0.00
);

-- =======================================================
-- ORDER DETAIL TABLE
-- =======================================================
--
-- Represents items inside an order.
--
-- Required information:
-- - Unique identifier
-- - Reference to an order
-- - Reference to a menu item
-- - Quantity
-- - Item price at purchase time
--
-- Requirements:
-- - Each detail record must belong to one order.
-- - Each detail record must reference one menu item.
-- - Quantity must always be greater than zero.
-- - Store the item's price at the moment of purchase.
--
-- CREATE TABLE ...

CREATE TABLE order_detail(
    id SERIAL PRIMARY KEY,
    order_id INT NOT NULL REFERENCES orders(id),
    menu_item_id INT NOT NULL REFERENCES menuItem(id),
    quantity INT NOT NULL CHECK ( quantity > 0 ),
    unit_price DECIMAL(10, 2) NOT NULL
);

-- =======================================================
-- INITIAL MENU DATA
-- =======================================================
--
-- Insert at least 3 food or drink items.
--
-- Example categories:
-- - Pizza
-- - Burger
-- - Pasta
-- - Drink
--
-- INSERT INTO ...

INSERT INTO menuItem(
    name, description, price, category
) VALUES('Pizza Margherita', 'Classic pizza with tomato sauce and mozzarella', 10.00, 'Pizza'),
         ('Beef Burger', 'Juicy beef patty with cheese, lettuce, and tomato', 8.50, 'Burger'),
         ('Pasta Alfredo', 'Creamy pasta with grilled chicken and parmesan', 12.00, 'Pasta'),
         ('Coca Cola', 'Cold soft drink', 2.00, 'Drink');


-- =======================================================
-- OPTIONAL TEST DATA
-- =======================================================
--
-- You may insert sample users and orders for testing.
-- This section is optional.
--
-- INSERT INTO ...

--AI generated
INSERT INTO users (
                   username, password, email
) VALUES('ali_dev', '$2a$12$K8M6O2wWfG1...hashed_long_string...', 'ali@email.com'),
        ('sara_k', '$2a$12$R9P2m1vXyZ7...hashed_long_string...', NULL),
        ('reza_food', '$2a$12$T5N8b9zQpW3...hashed_long_string...', 'reza@email.com');

INSERT INTO orders (
                    user_id, total_price
) VALUES(1, 18.50),  -- سفارش اول علی
        (2, 12.00),  -- سفارش سارا
        (1, 20.00);  -- سفارش دوم علی

-- =======================================================
-- VERIFICATION QUERIES
-- =======================================================
--
-- Uncomment these queries to verify your database.
--
SELECT * FROM users;
SELECT * FROM menuItem;
SELECT * FROM orders;
SELECT * FROM order_detail;