package task4;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Scanner;

public class TransactionTask {

    //Scanner init
    private static Scanner scan;
    static String input;

    // SQL Connection inits
    private static Connection connection = null;
    public static Statement statement = null;
    static final String dbuser = "root";
    static final String dbpassword = "";
    static final String dbname = "school";
    static final String dbport = "3306";

    public static void main(String[] args) {

        scan = new Scanner(System.in);

        HashMap<String, String> transactionDetails = new HashMap<String, String>();

            System.out.println("Please fill in all the fields required:");
            System.out.println("(TERMINAL ID ~ CARD NUMBER ~ EXP DATE ~ PIN BLOCK ~ AMOUNT ~ PROMO CODE)");
            System.out.println("<-==============================================->");

            String input = scan.nextLine();
            String[] fields = input.split("~");

            transactionDetails.put("TerminalID", fields[0].trim());
            transactionDetails.put("Card NR", fields[1]);
            transactionDetails.put("Expiration Date", fields[2]);
            transactionDetails.put("PinBlock", fields[3]);
            transactionDetails.put("Amount", fields[4]);
            transactionDetails.put("PromoCode", fields[5]);

            System.out.println("<-==============================================->");

            // Assigning variables to use for validation
            String cardnr = transactionDetails.get("Card NR");
            String promocode = transactionDetails.get("PromoCode");
            String expdate = transactionDetails.get("Expiration Date");
            String amount = transactionDetails.get("Amount");
            String pin = transactionDetails.get("PinBlock");

            // Validation begin
            if (cardnr.length() < 12 && cardnr.length() > 18 && !cardnr.matches("^-?\\d+$")) {
                System.out.println("Card number should be between 12 and 18 numbers.");
                return;
            } else if (promocode.length() > 13) {
                System.out.println("Invalid promotion code");
                return;
            } else if (expdate.length() > 0 && !validateDate(expdate)) {
                System.out.println("Expiration date is not in valid format or has expired.");
                return;
            } else if (amount.length() > 0 && !isFloat(amount)) {
                System.out.println("Invalid amount entered.");
                return;
            } else if (pin.length() > 0 && !isHex(pin)) {
                System.out.println("You have entered an invalid PIN Block");
                return;
            } else
                System.out.println("Everything is valid!");

            UpdateDB(transactionDetails);
        }



    // Checking if a value is HEX
    public static boolean isHex(String hex) {
        try {
            Long.parseLong(hex, 16);
            return true;
        } catch (NumberFormatException ex) {
            return false;
        }
    }


    // Checking if value is float
    public static boolean isFloat(String f) {
        try {
            Float.parseFloat(f);
            return true;
        } catch (NumberFormatException ex) {
            return false;
        }
    }

    // Method for validating date if its in correct format
    public static boolean validateDate(String expdate) {
        SimpleDateFormat sdf = new SimpleDateFormat("MM/yy");
        Date date = new Date();

        try {
            Date date1 = sdf.parse(expdate);
            return date1.after(date);
        } catch (ParseException ex) {
            return false;
        }
    }

    // Method for checking if String is Integer
    // Not going to use parseInt, cuz this is simpler and doesnt throw anything.

    static boolean isInt(String s) {

        if (s.matches("^[+-]?\\d+$"))
            return true;
        else
            return false;
    }

    //SQL Connection
    private static void connect()
    {
        try {
        Class.forName("com.mysql.jdbc.Driver");
        connection = DriverManager.getConnection("jdbc:mysql://localhost:" + dbport + "/" + dbname, dbuser, dbpassword);
        }
        catch (Exception e){
            System.out.println(e);
        }
    }

    private static void disconnect()
    {
        try
        {
            connection.close();
            connection = null;
        }
        catch (Exception e)
        {
            System.out.println(e);
        }
    }

    private static void UpdateDB(HashMap<String, String> data)
    {
        // try to create table if not exists
        initTable();

        connect();
        try {
            statement = connection.createStatement();

            String sql = String.format("INSERT INTO `transactions` (`terminal_id`, `cardnr`, `expdate`, `pinblock`, `amount`, `promocode`) VALUES "
                    + "('%s', '%s', '%s', '%s', '%s', '%s');",
                    data.get("TerminalID"),
                    data.get("Card NR"),
                    data.get("Expiration Date"),
                    data.get("PinBlock"),
                    data.get("Amount"),
                    data.get("PromoCode")
                );
            System.out.println(sql);

            statement.executeUpdate(sql);

        }
        catch(SQLException e)
        {
            // Custom error handling for 1062 (sql - duplicate entry)
            // Just for example how to handle and output custom error messages :D
            if (e.getErrorCode() == 1062)
            {
                System.out.println("This transaction already exists!");
            }
            else
            {
                System.out.println(e);
            }
        }

        disconnect();
    }

    // initialize if the table transactions doesnt exist
    private static void initTable()
    {
        connect();

        try{
            statement = connection.createStatement();

            String sql = "CREATE TABLE IF NOT EXISTS `transactions` ( `terminal_id` VARCHAR(12) NOT NULL , `cardnr` VARCHAR(16) NOT NULL , `expdate` VARCHAR(12) NOT NULL , `pinblock` VARCHAR(12) NOT NULL , `amount` VARCHAR(12) NOT NULL , `promocode` VARCHAR(12) NOT NULL , PRIMARY KEY (`terminal_id`)) ENGINE = InnoDB;";

            statement.execute(sql);
        }
        catch(Exception e)
        {
            System.out.println(e);
        }

        disconnect();
    }
}