LeaveManagementSystem

use simple java functions to develops this Leave Management System import java.util.*;

// Employee Class class Employee { String id; String name; String password; int leaveBalance;

// Constructor
Employee(String id, String name, String password, int leaveBalance) {
    this.id = id;
    this.name = name;
    this.password = password;
    this.leaveBalance = leaveBalance;
}

// Method to apply for leave
public void applyLeave(int days) {
    if (leaveBalance >= days) {
        leaveBalance -= days;
        System.out.println("Leave applied for " + days + " days.");
    } else {
        System.out.println("Insufficient leave balance.");
    }
}

// Method to view leave balance
public void viewLeaveBalance() {
    System.out.println("Your available leave balance is: " + leaveBalance + " days.");
}

// Main method to test Employee class functionality
public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    // Create an Employee object for testing
    Employee emp = new Employee("29", "vedika", "ved123", 20);
    System.out.println("Testing Employee class...");
    System.out.println("Welcome " + emp.name);
    
    // Test applying leave
    System.out.print("Enter number of days you want to apply for leave: ");
    int days = scanner.nextInt();
    emp.applyLeave(days);

    // Test viewing leave balance
    emp.viewLeaveBalance();
}

}

// LeaveRequest Class class LeaveRequest { String empId; String startDate; String endDate; String status;

LeaveRequest(String empId, String startDate, String endDate) {
    this.empId = empId;
    this.startDate = startDate;
    this.endDate = endDate;
    this.status = "Pending";
}

public void approve() {
    status = "Approved";
    System.out.println("Leave request approved.");
}

public void reject() {
    status = "Rejected";
    System.out.println("Leave request rejected.");
}

@Override
public String toString() {
    return "Employee ID: " + empId + ", From: " + startDate + " To: " + endDate + " Status: " + status;
}

}

// Manager Class class Manager { String id; String password;

Manager(String id, String password) {
    this.id = id;
    this.password = password;
}

public void approveRejectLeave(HashMap<Integer, LeaveRequest> leaveRequests) {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter Leave Request ID to approve/reject:");
    int requestId = scanner.nextInt();
    LeaveRequest request = leaveRequests.get(requestId);
    if (request != null && request.status.equals("Pending")) {
        System.out.println(request);
        System.out.println("Approve or Reject? (A/R): ");
        char choice = scanner.next().charAt(0);
        if (choice == 'A' || choice == 'a') {
            request.approve();
        } else if (choice == 'R' || choice == 'r') {
            request.reject();
        } else {
            System.out.println("Invalid choice.");
        }
    } else {
        System.out.println("Invalid request ID or already processed.");
    }
}

}

// Main class (LeaveManagementSystemApp) public class LeaveManagementSystemApp { static Scanner scanner = new Scanner(System.in); static HashMap<String, Employee> employees = new HashMap<>(); static HashMap<String, Manager> managers = new HashMap<>(); static HashMap<Integer, LeaveRequest> leaveRequests = new HashMap<>(); static int leaveRequestId = 1;

public static void main(String[] args) {
    // Adding sample data
    employees.put("29", new Employee("29", "vedika", "ved123", 20));
    employees.put("E002", new Employee("E002", "Bob", "emp456", 15));
    managers.put("M001", new Manager("M001", "mgr123"));

    while (true) {
        System.out.println("Welcome to the Leave Management System");
        System.out.println("1. Employee Login");
        System.out.println("2. Manager Login");
        System.out.println("3. Exit");
        System.out.print("Enter your choice: ");
        int choice = scanner.nextInt();

        if (choice == 1) {
            employeeLogin();
        } else if (choice == 2) {
            managerLogin();
        } else if (choice == 3) {
            System.out.println("Exiting...");
            break;
        } else {
            System.out.println("Invalid choice. Please try again.");
        }
    }
}

public static void employeeLogin() {
    System.out.print("Enter Employee ID: ");
    String empId = scanner.next();
    System.out.print("Enter Password: ");
    String password = scanner.next();

    if (employees.containsKey(empId) && employees.get(empId).password.equals(password)) {
        employeeMenu(empId);
    } else {
        System.out.println("Invalid credentials.");
    }
}

public static void employeeMenu(String empId) {
    while (true) {
        System.out.println("Welcome, " + employees.get(empId).name);
        System.out.println("1. Apply for Leave");
        System.out.println("2. View Leave Balance");
        System.out.println("3. Logout");
        System.out.print("Enter your choice: ");
        int choice = scanner.nextInt();

        if (choice == 1) {
            System.out.print("Enter number of days you want to apply for: ");
            int days = scanner.nextInt();
            employees.get(empId).applyLeave(days);
            if (days <= employees.get(empId).leaveBalance) {
                System.out.print("Enter start date of leave (YYYY-MM-DD): ");
                String startDate = scanner.next();
                System.out.print("Enter end date of leave (YYYY-MM-DD): ");
                String endDate = scanner.next();
                leaveRequests.put(leaveRequestId++, new LeaveRequest(empId, startDate, endDate));
            }
        } else if (choice == 2) {
            employees.get(empId).viewLeaveBalance();
        } else if (choice == 3) {
            break;
        } else {
            System.out.println("Invalid choice. Please try again.");
        }
    }
}

public static void managerLogin() {
    System.out.print("Enter Manager ID: ");
    String mgrId = scanner.next();
    System.out.print("Enter Password: ");
    String password = scanner.next();

    if (managers.containsKey(mgrId) && managers.get(mgrId).password.equals(password)) {
        managerMenu(mgrId);
    } else {
        System.out.println("Invalid credentials.");
    }
}

public static void managerMenu(String mgrId) {
    while (true) {
        System.out.println("Welcome, Manager");
        System.out.println("1. View Pending Leave Requests");
        System.out.println("2. Approve/Reject Leave Request");
        System.out.println("3. Logout");
        System.out.print("Enter your choice: ");
        int choice = scanner.nextInt();

        if (choice == 1) {
            viewPendingRequests();
        } else if (choice == 2) {
            Manager manager = managers.get(mgrId);
            manager.approveRejectLeave(leaveRequests);
        } else if (choice == 3) {
            break;
        } else {
            System.out.println("Invalid choice. Please try again.");
        }
    }
}

public static void viewPendingRequests() {
    System.out.println("Pending Leave Requests:");
    for (LeaveRequest request : leaveRequests.values()) {
        if (request.status.equals("Pending")) {
            System.out.println(request);
        }
    }
}

}