package com.example.scheduler_server;

import java.io.*;
import java.net.*;
import java.util.*;

/*
    Name: ScheduleServer
    Description: Establishes the connection to the database, and opens the  scheduling sever for scheduling clients
    to connect to.
 */
public class ScheduleServer {
    private final DataBaseQuery dbQuery;
    private final int port;
    private final String ip;
    private final Set<UserThread> userThreads = new HashSet<>(); // notify when there are changes

    /*
    Name: ScheduleServer
    Parameters:
        String ip: The IP address for the server to bind to.
        int port: The port the server will listen to.
        String dbURL: The URL of the database
        String dbUser: The username of the database.
        String dbPass: The password of the database.
    Description: Changes when the shift starts.
    Return: ScheduleServer
     */
    public ScheduleServer(String ip, int port, String dbURL, String dbUser, String dbPass) {
        this.ip = ip;
        this.port = port;
        this.dbQuery = new DataBaseQuery(dbURL, dbUser, dbPass);
    }

    /*
    Name: execute
    Description: This runs on an infinite loop where it waits for new clients makes a new thread for its requests.
     */
    public void execute() {
        try (ServerSocket serverSocket = new ServerSocket(port, 50, InetAddress.getByName(ip))) {
            System.out.println("Scheduling server is listening on port " + port);

            while (true) {
                Socket socket = serverSocket.accept();
                System.out.println("New user connected");

                UserThread newUser = new UserThread(socket, this, this.dbQuery);
                userThreads.add(newUser);
                newUser.start();
            }
        } catch (IOException error) {
            System.out.println("Error in the server :" + error.getMessage());
            error.printStackTrace();
        }
    }

    /*
    Name: Broadcast
    Parameters:
        String message: Message to be sent to all the clients.
    Description: Sends a message to all current online schedule clients.
    Return: void
     */
    void broadcast(String message) {
        for (UserThread aUser : userThreads) {
            aUser.sendMessage(message);
        }
    }

    /*
    Name: removeUser
    Parameters:
        UserThread aUser: The thread responsible for listening and sending message to a scheduling client.
    Description: Removes the connection of a scheduling client from the server.
    Return: void
     */
    void removeUser(UserThread aUser) {
        userThreads.remove(aUser);
    }

    public static void main(String[] args) throws IOException {
        Properties serverProp = new Properties();
        FileInputStream in = new FileInputStream("./src/main/java/com/example/scheduler_server/server.properties");
        serverProp.load(in);
        ScheduleServer server = new ScheduleServer(serverProp.getProperty("ipAddress"), Integer.parseInt(serverProp.getProperty("port")),
                serverProp.getProperty("dbURL"), serverProp.getProperty("dbUser"), serverProp.getProperty("dbPass"));
        server.execute();
    }
}