import java.sql.*;
import java.util.Scanner;

public class Main {
    static final String DB_CONNECTION = "jdbc:mysql://localhost:3306/orders";
    static final String DB_USER = "root";
    static final String DB_PASSWORD = "root";

    static Connection conn;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        try {
            try {
                conn = DriverManager.getConnection(DB_CONNECTION, DB_USER, DB_PASSWORD);
                 initDB();

                while (true) {
                    System.out.println("1: add new product");
                    System.out.println("2: make an order");
                    System.out.println("3: view orders");
                    System.out.print("-> ");

                    String s = sc.nextLine();
                    switch (s) {
                        case "1":
                            addProduct();
                            break;
                        case "2":
                            makeAnOrder();
                            break;
                        case "3":
                            viewOrders();
                            break;
                        default:
                            return;
                    }
                }
            } finally {
                sc.close();
                if (conn != null) conn.close();
            }
        } catch (SQLException ex) {
            ex.printStackTrace();
            return;
        }
    }


    private static void initDB() throws SQLException {
        Statement st = conn.createStatement();
        try {
            st.execute("DROP TABLE IF EXISTS Orders");
            st.execute("DROP TABLE IF EXISTS  Clients");
            st.execute("DROP TABLE IF EXISTS Products");
            st.execute("CREATE TABLE Clients (id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
                                              username VARCHAR(50) NOT NULL, email VARCHAR(30),
                                              phone VARCHAR (20) NOT NULL UNIQUE) ");
            st.execute("CREATE TABLE Products (id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
                                               name VARCHAR(50) NOT NULL,
                                               price DOUBLE NOT NULL)");
            st.execute("CREATE TABLE Orders(id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
                                            client_id INT,
                                            product_id INT)");
               } finally {
            st.close();
                 }
    }

    private static void addProduct() throws SQLException {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter product name:");
        String name = sc.nextLine();
        System.out.println("Enter product price:");
        double price = sc.nextDouble();

        PreparedStatement ps = conn.prepareStatement("INSERT INTO Products (name,price) VALUES(?, ?)");
        try {
            ps.setString(1, name);
            ps.setDouble(2, price);
            ps.executeUpdate();
        } finally {
            ps.close();
        }
    }

    private static void makeAnOrder() throws SQLException {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter client's name:");
        String username = sc.nextLine();
        System.out.println("Enter client's email:");
        String email = sc.nextLine();
        System.out.println("Enter client's phone:");
        String phone = sc.nextLine();
        viewAllProducts();
        System.out.println("Choose a product. Enter product's id:");
        int productID = sc.nextInt();

        int usernameID = findUserID(username, email, phone);
        addOrder(usernameID, productID);
    }


    private static void addClient(String username, String email, String phone) throws SQLException {
        PreparedStatement ps = conn.prepareStatement("INSERT INTO Clients (username, email, phone) VALUES(?, ?, ?)");
        try {
            ps.setString(1, username);
            ps.setString(2, email);
            ps.setString(3, phone);
            ps.executeUpdate();
        } finally {
            ps.close();
        }

    }

    private static int findUserID(String username, String email, String phone) throws SQLException {
        PreparedStatement ps = conn.prepareStatement("SELECT id FROM Clients WHERE phone = ?");
        ResultSet rs = null;
        int userID = 0;
        try {
            ps.setString(1, phone);
            rs = ps.executeQuery();

            while (true) {
                if (rs.next()) {
                    userID = Integer.parseInt(rs.getString("id"));
                    break;
                } else {
                    addClient(username, email, phone);
                    rs = ps.executeQuery();
                }
            }

        } finally

        {
            rs.close();
            ps.close();
        }

        return userID;
    }

    private static void viewAllProducts() throws SQLException {
        PreparedStatement ps = conn.prepareStatement("SELECT * FROM Products");
        printTable(ps);
    }

    private static void addOrder(int usernameID, int productID) throws SQLException {
        PreparedStatement ps = conn.prepareStatement("INSERT INTO Orders (client_id, product_id) VALUES(?, ?)");

        try {
            ps.setInt(1, usernameID);
            ps.setInt(2, productID);
            ps.executeUpdate();
        } finally {
            ps.close();
        }
    }

    private static void viewOrders() throws SQLException {
        PreparedStatement ps = conn.prepareStatement("SELECT p.name,p.price, cl.username, cl.email, cl.phone FROM Products p, Orders ord, Clients cl WHERE cl.id = ord.client_id AND p.id = ord.product_id");
        printTable(ps);

    }

    private static void printTable(PreparedStatement ps) throws SQLException {
        try {
            ResultSet rs = ps.executeQuery();
            try {
                ResultSetMetaData md = rs.getMetaData();

                for (int i = 1; i <= md.getColumnCount(); i++) {
                    System.out.print(md.getColumnName(i) + "\t\t");
                }
                System.out.println();

                while (rs.next()) {
                    for (int i = 1; i <= md.getColumnCount(); i++) {
                        System.out.print(rs.getString(i) + "\t\t");
                    }
                    System.out.println();
                }
            } finally {
                rs.close();
            }
        } finally {
            ps.close();

        }
    }
}