import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.sql.*;
import java.util.ArrayList;

//Database server
public class DataServer extends Thread {
    private String cabinNo;
    private Socket socket;
    private BufferedReader readInput;
    private PrintWriter writeOutput;
    private static ArrayList <String> usersOnline = new ArrayList<>();

    public DataServer(Socket socket) {
        this.socket = socket;
    }

    public void run() {
        boolean b = true;
        while (b) {
            try {
                //Declare new reader and writer to communicate with the client
                readInput = new BufferedReader((new InputStreamReader(socket.getInputStream())));
                writeOutput = new PrintWriter(socket.getOutputStream(), true);
                String storeInput = readInput.readLine();
                connectToDb(storeInput);
                b = false;
            }
            catch (IOException e) {
                System.out.println(e.getMessage());
            }
            catch (NullPointerException e){
                System.out.println(e.getMessage());
            }
            catch (SQLException e){
                System.out.println(e);
            }
        }
    }
    //Method that takes the readInput string and sorts it into a String array in String chunks
    public String [] processInput(String input){
        String [] processedInput = input.split(",");
        return processedInput;
    }
    //Method that checks if a user account is logged in
    public boolean checkUsersOnline(String input){
        for(int i = 0; i < usersOnline.size(); i++){
            if(usersOnline.get(i).equals(input)){//readInput.equals(usersOnline.get(i))
                return true;
            }
            else{
                return false;
            }
        }
        return false;
    }
    //Connection method that connects to a DB and performs tasks on behalf of a client
    public void connectToDb(String input) throws SQLException{
        //First line takes a String and cuts it into chunks using processInput method
        //The first chunk in every message is a key that is later used by a switch statement
        //The key is essential for the program to know which action to perform
        String [] storeInput = processInput(input);


        String username = "Client";
        String password = "ClientAccess";
        String databaseName = "Cruise";
        String databasePath = "jdbc:mysql://localhost:3306/"+databaseName+"?autoReconnect=true&useSSL=false";

        //String schoolDataBase = studentnet.cst.beds.ac.uk; //school DB
        //localhost:3306 //local DB
        try {
            //Try to make a connection to DB
            java.sql.Connection connection = null;
            Statement statement = null;
            ResultSet results = null;

            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection(databasePath, username, password);
            statement = connection.createStatement();


            //Creating a switch statement that processes the incoming message from the client
            //Using the value of the first element of the Array, the switch statement takes appropriate action
            switch (storeInput[0]) {
                case "1":
                    //First switch case: Register user
                    //statement.executeUpdate("INSERT INTO customer (cabinNo, email, userpw) VALUE ("+storeInput[1]+",'"+storeInput[2]+"','"+storeInput[3]+"');");
                    PreparedStatement prepStatementRegister = connection.prepareStatement
                            ("INSERT INTO customer (cabinNo, email, userpw) VALUE (?, ?, ?)");
                    prepStatementRegister.setString(1,storeInput[1]);
                    prepStatementRegister.setString(2,storeInput[2]);
                    prepStatementRegister.setString(3,storeInput[3]);
                    prepStatementRegister.executeUpdate();

                    /*while (results.next()) {
                        System.out.println(results.getString("cabinNo"));
                    }*/
                    break;
                case "2":
                    //PreparedStatement prepStatementLogIn = connection.prepareStatement("SELECT * FROM customer;");
                    results = statement.executeQuery("SELECT * FROM customer;");
                    while(results.next()){
                        if(storeInput[1].equals(results.getString("cabinNo"))){
                            if(storeInput[2].equals(results.getString("userpw")) && checkUsersOnline(storeInput[1])==false){
                                System.out.println("logged in");
                                usersOnline.add(storeInput[1]);
                                cabinNo = storeInput[1];
                            }
                            else{
                                System.out.println("user already online");
                            }
                        }
                    }
                    break;
                case "3":

                    System.out.println(cabinNo);

                    break;
            }
        }
        catch(SQLException e){
            System.out.println("SQL exception");
        }
        catch(ClassNotFoundException e){
            System.out.println("Class not found exception");
        }
        catch(ArrayIndexOutOfBoundsException e){
            System.out.println("Array Index out of bounds");
        }