if_else

import java.util.Scanner;

public class if_else {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // TODO: SECTION 1 - Basic If-Else Statements

        // Example 1: Check if a number is odd or even
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();

        if (number % 2 == 0) {
            System.out.println(number + " is even.");
        } else {
            System.out.println(number + " is odd.");
        }

        // Example 2: Age eligibility for voting
        System.out.print("Enter your age: ");
        int age = scanner.nextInt();
        if (age >= 18) {
            System.out.println("You are eligible to vote.");
        } else {
            System.out.println("You are not eligible to vote.");
            System.out.println("You need " + (18 - age) + " more years to be eligible.");
        }

        // Example 3: Check if a number is positive, negative, or zero
        System.out.print("Enter a number: ");
        int theNumber = scanner.nextInt();

        if (theNumber > 0) {
            System.out.println("The number is positive.");
        } else if (theNumber < 0) {
            System.out.println("The number is negative.");
        } else {
            System.out.println("The number is zero.");
        }

        // Example 4: Password strength checker
        System.out.print("Enter password length: ");
        int passwordLength = scanner.nextInt();

        if (passwordLength >= 12) {
            System.out.println("Strong password length!");
        } else if (passwordLength >= 8) {
            System.out.println("Medium password strength. Consider making it longer.");
        } else if (passwordLength >= 6) {
            System.out.println("Weak password. Should be at least 8 characters.");
        } else {
            System.out.println("Very weak password. Must be at least 6 characters.");
        }


        // TODO: SECTION 2 - Multiple Conditions
        System.out.println("\n=== Multiple Conditions ===\n");

        // Example 1: Find the maximum of three numbers
        System.out.print("Enter the first number: ");
        int number1 = scanner.nextInt();
        System.out.print("Enter the second number: ");
        int number2 = scanner.nextInt();
        System.out.print("Enter the third number: ");
        int number3 = scanner.nextInt();

        if (number1 >= number2 && number1 >= number3) {
            System.out.println("The maximum number is: " + number1);
        } else if (number2 >= number1 && number2 >= number3) {
            System.out.println("The maximum number is: " + number2);
        } else {
            System.out.println("The maximum number is: " + number3);
        }

        // Example 2: Grade classification system
        System.out.print("Enter student's score (0-100): ");
        int studentScore = scanner.nextInt();

        if (studentScore >= 90) {
            System.out.println("Grade: A (Excellent)");
        } else if (studentScore >= 80) {
            System.out.println("Grade: B (Good)");
        } else if (studentScore >= 70) {
            System.out.println("Grade: C (Average)");
        } else if (studentScore >= 60) {
            System.out.println("Grade: D (Below Average)");
        } else if (studentScore >= 0) {
            System.out.println("Grade: F (Fail)");
        } else {
            System.out.println("Invalid score! Please enter a score between 0-100.");
        }

        // TODO: SECTION 3 - Practical Examples
        System.out.println("\n=== Practical Applications ===\n");

        // Example 1: ATM Simulation
        double accountBalance = 500.0;
        String message = "";

        System.out.println("--- ATM Simulation ---");
        System.out.println("Welcome to ATM! Your balance is $" + accountBalance);
        System.out.println("Enter 1 to deposit, 2 to withdraw, 3 to check balance:");
        int choice = scanner.nextInt();

        if (choice == 1) {
            System.out.print("Enter the amount to deposit: ");
            double depositAmount = scanner.nextDouble();
            if (depositAmount > 0 && depositAmount <= 10000) {
                accountBalance += depositAmount;
                message = "Successfully deposited $" + depositAmount +
                        ". Your new balance is $" + accountBalance + ".";
            } else if (depositAmount <= 0) {
                message = "Invalid amount! Deposit amount must be greater than $0.";
            } else {
                message = "Transaction limit exceeded! Maximum deposit is $10,000.";
            }
        } else if (choice == 2) {
            System.out.print("Enter the amount to withdraw: ");
            double withdrawalAmount = scanner.nextDouble();
            if (withdrawalAmount >= 10) {
                if (withdrawalAmount <= accountBalance) {
                    if (withdrawalAmount <= 1000) {
                        accountBalance -= withdrawalAmount;
                        message = "Successfully withdrew $" + withdrawalAmount +
                                ". Your remaining balance is $" + accountBalance + ".";
                    } else {
                        message = "Daily withdrawal limit exceeded! Maximum withdrawal is $1,000.";
                    }
                } else {
                    message = "Insufficient funds! Current balance: $" + accountBalance + ".";
                }
            } else {
                message = "Transaction failed! Minimum withdrawal amount is $10.";
            }
        } else if (choice == 3) {
            message = "Your current balance is $" + accountBalance + ".";
        } else {
            message = "Invalid choice! Please select 1, 2, or 3.";
        }
        System.out.println(message);

        // Example 2: Shopping Discount Calculator
        System.out.println("\n--- Shopping Discount Calculator ---");
        int loyaltyPoints = 0;
        double discount = 0;
        String membershipLevel = "";

        System.out.print("Enter the total amount spent: $");
        double amountSpent = scanner.nextDouble();
        System.out.print("Are you a VIP member? (true/false): ");
        boolean isVipMember = scanner.nextBoolean();

        // Determine discount based on amount and membership
        if (isVipMember) {
            if (amountSpent >= 200) {
                discount = 0.30; // 30% VIP discount
                membershipLevel = "VIP Gold";
            } else if (amountSpent >= 100) {
                discount = 0.25; // 25% VIP discount
                membershipLevel = "VIP Silver";
            } else {
                discount = 0.15; // 15% VIP discount
                membershipLevel = "VIP Bronze";
            }
        } else {
            if (amountSpent >= 200) {
                discount = 0.15; // 15% regular discount
                membershipLevel = "Regular Gold";
            } else if (amountSpent >= 100) {
                discount = 0.10; // 10% regular discount
                membershipLevel = "Regular Silver";
            } else if (amountSpent >= 50) {
                discount = 0.05; // 5% regular discount
                membershipLevel = "Regular Bronze";
            }
        }

        loyaltyPoints = (int) (amountSpent / 10); // 1 point for every $10
        if (isVipMember) {
            loyaltyPoints *= 2; // VIP members get double points
        }

        // Calculate final amount
        double discountedAmount = amountSpent - (amountSpent * discount);
        double tax = discountedAmount * 0.08; // 8% tax
        double finalAmount = discountedAmount + tax;

        System.out.println("Membership Level: " + membershipLevel);
        System.out.println("Original Amount: $" + amountSpent);
        if (discount > 0) {
            System.out.println("You qualify for a " + (discount * 100) + "% discount!");
            System.out.println("Discounted Amount: $" + discountedAmount);
        } else {
            System.out.println("No discount available for this amount.");
        }
        System.out.println("Loyalty Points Earned: " + loyaltyPoints + " points");
        System.out.println("Tax (8%): $" + tax);
        System.out.println("Final Amount: $" + finalAmount);

        // Example 3: Calculator simulation
        System.out.print("Enter first number: ");
        double calcNum1 = scanner.nextDouble();
        System.out.print("Enter operator (+, -, *, /): ");
        String operator = scanner.next();
        System.out.print("Enter second number: ");
        double calcNum2 = scanner.nextDouble();

        double calcResult = 0;
        String calcMessage = "";

        if (operator.equals("+")) {
            calcResult = calcNum1 + calcNum2;
            calcMessage = calcNum1 + " + " + calcNum2 + " = " + calcResult;
        } else if (operator.equals("-")) {
            calcResult = calcNum1 - calcNum2;
            calcMessage = calcNum1 + " - " + calcNum2 + " = " + calcResult;
        } else if (operator.equals("*")) {
            calcResult = calcNum1 * calcNum2;
            calcMessage = calcNum1 + " * " + calcNum2 + " = " + calcResult;
        } else if (operator.equals("/")) {
            if (calcNum2 != 0) {
                calcResult = calcNum1 / calcNum2;
                calcMessage = calcNum1 + " / " + calcNum2 + " = " + calcResult;
            } else {
                calcMessage = "Error: Division by zero!";
            }
        } else {
            calcMessage = "Error: Invalid operator!";
        }

        System.out.println(calcMessage);

        // Example 4: Employee Salary Calculator
        System.out.println("--- Employee Salary Calculator ---");
        System.out.print("Enter employee type (1=Full-time, 2=Part-time, 3=Contract): ");
        int employeeType = scanner.nextInt();
        System.out.print("Enter hours worked this week: ");
        double hoursWorked = scanner.nextDouble();
        System.out.print("Enter hourly rate: $");
        double hourlyRate = scanner.nextDouble();
        System.out.print("Enter years of experience: ");
        int experience = scanner.nextInt();

        double baseSalary = 0;
        double overtimePay = 0;
        double bonus = 0;
        String employeeStatus = "";

        if (employeeType == 1) { // Full-time
            employeeStatus = "Full-time";
            if (hoursWorked <= 40) {
                baseSalary = hoursWorked * hourlyRate;
            } else {
                baseSalary = 40 * hourlyRate;
                overtimePay = (hoursWorked - 40) * hourlyRate * 1.5; // Time and a half
            }

            // Experience bonus for full-time employees
            if (experience >= 10) {
                bonus = baseSalary * 0.15; // 15% bonus
            } else if (experience >= 5) {
                bonus = baseSalary * 0.10; // 10% bonus
            } else if (experience >= 2) {
                bonus = baseSalary * 0.05; // 5% bonus
            }
        } else if (employeeType == 2) { // Part-time
            employeeStatus = "Part-time";
            if (hoursWorked <= 20) {
                baseSalary = hoursWorked * hourlyRate;
            } else {
                baseSalary = hoursWorked * hourlyRate;
                System.out.println("Warning: Part-time employee worked more than 20 hours!");
            }
        } else if (employeeType == 3) { // Contract
            employeeStatus = "Contract";
            baseSalary = hoursWorked * hourlyRate;
            // No overtime or bonus for contract workers
        } else {
            employeeStatus = "Invalid";
            System.out.println("Invalid employee type!");
        }

        double totalPay = baseSalary + overtimePay + bonus;

        if (!employeeStatus.equals("Invalid")) {
            System.out.println("Employee Type: " + employeeStatus);
            System.out.println("Base Salary: $" + baseSalary);
            if (overtimePay > 0) {
                System.out.println("Overtime Pay: $" + overtimePay);
            }
            if (bonus > 0) {
                System.out.println("Experience Bonus: $" + bonus);
            }
            System.out.println("Total Pay: $" + totalPay);
        }

        // Example 5: Loan Approval System
        System.out.println("\n--- Loan Approval System ---");
        System.out.print("Enter annual income: $");
        double annualIncome = scanner.nextDouble();
        System.out.print("Enter credit score (300-850): ");
        int creditScore = scanner.nextInt();
        System.out.print("Enter loan amount requested: $");
        double loanAmount = scanner.nextDouble();
        System.out.print("Enter existing debt: $");
        double existingDebt = scanner.nextDouble();

        boolean loanApproved = false;
        double interestRate = 0;
        String loanDecision = "";
        double maxLoanAmount = 0;

        // Calculate debt-to-income ratio
        double monthlyIncome = annualIncome / 12;
        double monthlyDebt = existingDebt / 12;
        double debtToIncomeRatio = (monthlyDebt / monthlyIncome) * 100;

        // Determine maximum loan amount based on income
        maxLoanAmount = annualIncome * 4; // 4x annual income

        if (creditScore >= 750) {
            if (debtToIncomeRatio <= 30 && loanAmount <= maxLoanAmount) {
                loanApproved = true;
                interestRate = 3.5; // Excellent rate
                loanDecision = "Approved - Excellent Credit";
            } else if (debtToIncomeRatio <= 40) {
                loanApproved = true;
                interestRate = 4.0;
                loanDecision = "Approved - Good Standing";
                if (loanAmount > maxLoanAmount) {
                    loanAmount = maxLoanAmount;
                    loanDecision += " (Reduced Amount)";
                }
            } else {
                loanDecision = "Denied - High Debt-to-Income Ratio";
            }
        } else if (creditScore >= 650) {
            if (debtToIncomeRatio <= 25 && loanAmount <= maxLoanAmount * 0.8) {
                loanApproved = true;
                interestRate = 5.5;
                loanDecision = "Approved - Average Credit";
            } else {
                loanDecision = "Denied - Insufficient Credit/Income";
            }
        } else if (creditScore >= 550) {
            if (debtToIncomeRatio <= 20 && loanAmount <= maxLoanAmount * 0.5) {
                loanApproved = true;
                interestRate = 8.0;
                loanDecision = "Approved - High Risk";
            } else {
                loanDecision = "Denied - Poor Credit";
            }
        } else {
            loanDecision = "Denied - Credit Score Too Low";
        }

        System.out.println("Credit Score: " + creditScore);
        System.out.println("Debt-to-Income Ratio: " + String.format("%.1f", debtToIncomeRatio) + "%");
        System.out.println("Maximum Eligible Amount: $" + maxLoanAmount);
        System.out.println("Loan Decision: " + loanDecision);

        if (loanApproved) {
            System.out.println("Approved Amount: $" + loanAmount);
            System.out.println("Interest Rate: " + interestRate + "%");

            // Calculate monthly payment (simplified)
            double monthlyPayment = (loanAmount * (interestRate / 100 / 12)) /
                    (1 - Math.pow(1 + (interestRate / 100 / 12), -360)); // 30-year loan
            System.out.println("Estimated Monthly Payment: $" + String.format("%.2f", monthlyPayment));
        }

        // TODO: SECTION 4 - Shorthand if else (Ternary Operator)
        System.out.println("\n=== Ternary (Conditional) Operator ===\n");

        // Example 1: Simple odd/even check using ternary operator
        System.out.print("Enter a number for ternary check: ");
        int num = scanner.nextInt();
        String result = (num % 2 == 0) ? "The number is even" : "The number is odd";
        System.out.println(result);

        // Example 2: Find larger number between two numbers
        int num1 = 45;
        int num2 = 30;
        int largerNumber = (num1 > num2) ? num1 : num2;
        System.out.println("Larger number between " + num1 + " and " + num2 + ": " + largerNumber);

        // Example 3: Grade assignment using nested ternary
        int score = 85;
        String grade = (score >= 90) ? "A" :
                (score >= 80) ? "B" :
                        (score >= 70) ? "C" :
                                (score >= 60) ? "D" : "F";
        System.out.println("Score: " + score + ", Grade: " + grade);

        // Example 4: Age category classification
        System.out.print("Enter age for category check: ");
        int personAge = scanner.nextInt();
        String ageCategory = (personAge < 13) ? "Child" :
                (personAge < 20) ? "Teenager" :
                        (personAge < 60) ? "Adult" : "Senior";
        System.out.println("Age: " + personAge + ", Category: " + ageCategory);


        scanner.close();
        System.out.println("\n=== Program Complete ===");
    }
}