Java_Strings

import java.util.Scanner;
public class Java_Strings_New {
    public static void main(String[] args) {
//        TODO: example_1 -> string formatting
        String firstName = "John";
        String lastName = "Doe";
        int age = 30;
        double height = 5.9;
//        using String.format
        String formattedString =
                String.format("Name: %s %s, Age: %d, Height: %.2f feet"
                        , firstName, lastName, age, height);
        System.out.println("Formatted String (String.format): " + formattedString);
//        using printf
        System.out.printf("Formatted String (printf): Name: %s %s, Age: %d, Height: %.2f feet",
                firstName, lastName, age, height);
// ---------------------------string operations-------------------------------------------------------------------
        // TODO: example_2 -> string operations
        // concatenation
        String welcomeMessage_1 = "Welcome, " + firstName + " " + lastName + "!";
        String welcomeMessage_2 = "Welcome, " + firstName.concat(lastName) + "!";
        System.out.println(welcomeMessage_1);
        System.out.println(welcomeMessage_2);

        // substring
        String sentence = "The quick brown fox jumps over the lazy dog.";
        String subject = sentence.substring(4);
        System.out.println("Subject: " + subject);

        // trim
        String userInput = "   Spaces are not cool.   ";
        String cleanedInput = userInput.trim();
        System.out.println("Cleaned Input: " + cleanedInput);

        // Replace
        String originalString = "Hello, World!";
        String modifiedString = originalString.replace(',', '!');
        System.out.println("Original String: " + originalString);
        System.out.println("Modified String: " + modifiedString);

        // equals
        String str1 = "Java";
        String str2 = "java";
        boolean isEqual = str1.equals(str2);
        System.out.println("Case-sensitive comparison: " + isEqual);
        boolean isEqualIgnoreCase = str1.equalsIgnoreCase(str2);
        System.out.println("Case-insensitive comparison: " + isEqualIgnoreCase);

        // index of
        String new_sentence = "Java is fun and Java is powerful.";
        int indexOfJava = new_sentence.indexOf("Java");
        System.out.println("Index of 'Java': " + indexOfJava);

        // last index of
        String filePath = "/path/to/document.txt";
        int lastIndexOfDot = filePath.lastIndexOf('.');
        if (lastIndexOfDot != -1) {
            String fileExtension = filePath.substring(lastIndexOfDot + 1);
            System.out.println("File Extension: " + fileExtension);
        } else {
            System.out.println("No file extension found.");
        }

        // start with and end with
        String fileName_1 = "document.txt";
        boolean startsWithDoc = fileName_1.startsWith("doc");
        boolean endsWithTxt = fileName_1.endsWith("txt");
        System.out.println("Starts with 'doc': " + startsWithDoc);
        System.out.println("Ends with 'txt': " + endsWithTxt);

        // to char array
        String word = "Java";
        char[] charArray = word.toCharArray();
        System.out.print("Char Array: ");
        for (char c : charArray) {
            System.out.print(c + " ");
        }
        System.out.println();

        // TODO: Example_3 working on file path
        String filePathString = "C:\\Users\\Username\\Documents\\example.txt";

        // Get file name (with extension)
        int lastSeparatorIndex = filePathString.lastIndexOf("\\");
        int lastDotIndex = filePathString.lastIndexOf(".");
        String fileName_2 = (lastSeparatorIndex == -1) ? filePathString : filePathString.substring(lastSeparatorIndex + 1);
        System.out.println("File Name: " + fileName_2);

        // Get parent directory
        lastSeparatorIndex = filePathString.lastIndexOf("\\");
        String parentDirectory = (lastSeparatorIndex == -1) ? "" : filePathString.substring(0, lastSeparatorIndex);
        System.out.println("Parent Directory: " + parentDirectory);

        // Get file extension
        lastDotIndex = fileName_2.lastIndexOf(".");
        String fileExtension = (lastDotIndex == -1) ? "" : fileName_2.substring(lastDotIndex + 1);
        System.out.println("File Extension: " + fileExtension);

//        // TODO: example_4 working on user input
        String username = promptUser("Enter your username: ");
        String password = promptUser("Enter your password: ");
        // Validate and process user input
        if (isValidUsername(username) && isValidPassword(password)) {
            System.out.println("Registration successful! Welcome, " + username + "!");
        } else {
            System.out.println("Registration failed. Please check your input.");
        }
//
//        // TODO: example_5 extract product info
        String productInfo = "Product: Laptop | Brand: XYZ | Price: $1200.50";
        // Extract and print the product name
        String productName = extractProductName(productInfo);
        System.out.println("Product Name: " + productName);
        // Extract and print the brand
        String brand = extractBrand(productInfo);
        System.out.println("Brand: " + brand);
        // Extract and print the price
        double price = extractPrice(productInfo);
        System.out.println("Price: $" + price);

    }//end of main method
// ----------------------------------------------------------------------------------------------
    // TODO: example_4 -> working on user input
    // Method to prompt the user for input
    public static String promptUser(String prompt) {
        Scanner scanner = new Scanner(System.in);
        System.out.print(prompt);
        return scanner.nextLine().trim();
    }

    // Method to validate the username
    public static boolean isValidUsername(String username) {
        // Simple validation: Check if the username is not empty
        return !username.isEmpty();
    }

    // Method to validate the password
    public static boolean isValidPassword(String password) {
        // Complex validation: Check if the password has at least 6 characters,
        // and contains both lowercase and uppercase letters
        return password.length() >= 6 && containsLowerCase(password) && containsUpperCase(password);
    }

    // Helper method to check if the password contains lowercase letters
    public static boolean containsLowerCase(String password) {
        for (char ch : password.toCharArray()) {
            if (Character.isLowerCase(ch)) {
                return true;
            }
        }
        return false;
    }

    // Helper method to check if the password contains uppercase letters
    public static boolean containsUpperCase(String password) {
        for (char ch : password.toCharArray()) {
            if (Character.isUpperCase(ch)) {
                return true;
            }
        }
        return false;
    }
// ----------------------------------------------------------------------------------------------
    // TODO: example_5 -> extract product info
    // Method to extract the product name
    public static String extractProductName(String productInfo) {
        int nameSeparatorIndex = productInfo.indexOf("| Brand:");
        return (nameSeparatorIndex == -1) ? "" : productInfo.substring("Product: ".length(), nameSeparatorIndex).trim();
    }
    // Method to extract the brand
    public static String extractBrand(String productInfo) {
        int brandSeparatorIndex = productInfo.indexOf("| Price:");
        int nameSeparatorIndex = productInfo.indexOf("| Brand:");
        return (nameSeparatorIndex == -1 || brandSeparatorIndex == -1) ?
                "" : productInfo.substring(nameSeparatorIndex + "| Brand:".length(), brandSeparatorIndex).trim();
    }
    // Method to extract the price
    public static double extractPrice(String productInfo) {
        String priceSubstring = productInfo.substring(productInfo.indexOf("| Price:") + "| Price:".length()).trim();
        try {
            return Double.parseDouble(priceSubstring);
        } catch (NumberFormatException e) {
            System.out.println("Error parsing price information.");
            return 0.0; // Default value if parsing fails
        }
    }
}