# 5. What does this do? print("\007") Can you figure out why?

    # It is a ASCII Bell character.
    # It generates a beep sound or a system alert depending on the platform and environment where the code is executed.
    # It is often used to trigger attention or alert the user in certain situations or as a way to generate a simple sound signal in text-based interfaces.

    # BUT NOTHING HAPPENED ON MAC.



# 6. What does this do? print("abcdefg\rhijklmnop") Can you figure out why?

    # '\r' is a carriage return character
    # When the string is printed, the carriage return character '\r' causes the cursor to return to the beginning of the line. 
    # So when "hijklmnop" is printed, the cursor moves back to the start of the line, and the subsequent text "abcdefg" overwrites the initial characters.

    # The output is gonna be 'hijklmnop'.



# 7. To shut down the HTTP server afterward, using Ctrl + C to interrupt the execution of the Python program.

import http.server
import socketserver
from urllib.parse import urlparse, parse_qs

class MyRequestHandler(http.server.SimpleHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header('Content-type', 'text/plain')
        self.end_headers()
        output_string = "abcdefg\rhijklmnop"
        self.wfile.write(output_string.encode())

PORT = 8000
Handler = MyRequestHandler
httpd = socketserver.TCPServer(("", PORT), Handler)
print(f"Serving on port {PORT}")

httpd.serve_forever()

    # The HTTP server sends the response over the network to the client, which is typically a web browser.
    # In this function, the server sends an HTTP response with a status code of 200 and a content type of "text/plain". 
    # The response body is set to the string "abcdefg\rhijklmnop" encoded as bytes.
    # When the client receives this response, it interprets the \r character as a normal character and displays the entire string "abcdefg\rhijklmnop" as it is.

    # The '\r' character is a carriage return character, which is a control character used to return the cursor to the beginning of the current line.
    # The behavior of the carriage return character '\r' can depend on the platform and how the output is handled.

    # For example:
    # In Safari and Chrome, the "http://localhost:8000" shows:
        # abcdefg
        # hijklmnop
    # In Macbook Terminal, the "curl http://localhost:8000" shows:
        # hijklmnop%    



# 8. Think of a way someone might try to commit a crime or hide an embezzlement scheme using the answers to the above two questions.

    # The key is by manipulating or altering the output displayed on a web page versus what is actually happening in the system.

    # Case 1:
        # Show the false financial transactions to earn the cut.
    # Case 2:
        # Delivey the heist planning details and hide any suspicious activity.
    # Case 3:
        # Overwrite the previously displayed information for the false testimony purpose.



# 9. Think of how you would do input validation to prevent such a crime. Replace the code REPLACE ME here so the tests pass:

def validate(input_str):
    if '\r' in input_str or '\n' in input_str:
        raise ValueError("Crime detected!")

try:
    validate("abcdefg")
    print("✅ test1 pass!")
except ValueError:
    print("❌ test1 fail!")

try:
    validate("abcdefg\rhijklmnop")
    print("❌ test2 fail!")
except ValueError:
    print("✅ test2 pass!")

    # Test 1 pass means there is no ValueError
    # Test 2 pass means the ValueError has been detected