use std::io::{self, Read};
use std::process;

fn main() {

    let mut number_to_be_guessed:u8 = 0;
    let mut number_fix:u8 = 50;
    let mut computer_guess_number:u8 = 50;
    let mut guess_count:u8 = 1;
    let mut cheat = false;

    let mut inputIsValid = false;

    while !inputIsValid {
        match ask_for_user_input("Write a number between 1-100. Press ENTER when ready.").parse::<u8>() {
            Ok(parsed_input) => {
                if parsed_input <= 100 && parsed_input != 0 {
                    number_to_be_guessed = parsed_input;
                    inputIsValid = true;
                }
            }
            Err(e) => {
                ask_for_user_input("Incorrect number. Please enter a number between 1-100.");
            }
        }
    }

    while computer_guess_number != number_to_be_guessed && !cheat {
        println!("Guess attempt number {}. I am guessing {}.", guess_count, computer_guess_number);
        match ask_for_user_input("Is the number higher? Y/N").parse::<char>() {
            Ok(parsed_input) => {
                if parsed_input.to_ascii_lowercase() == 'y' {

                    if(computer_guess_number > number_to_be_guessed) {
                        cheat = true;
                    }

                    guess_count += 1;
                    number_fix /= 2;
                    computer_guess_number += number_fix;
                } else if parsed_input.to_ascii_lowercase() == 'n' {

                    if(computer_guess_number < number_to_be_guessed) {
                        cheat = true;
                    }

                    guess_count += 1;
                    number_fix /= 2;
                    computer_guess_number -= number_fix;

                } else {
                    println!("Incorrect input.");
                }

                if(number_fix < 2) {number_fix = 2}
            }
            Err(e) => {
                ask_for_user_input("Invalid input.");
            }
        }
    }

    if cheat { println!("I do not play with cheaters."); }

    if computer_guess_number == number_to_be_guessed {
        println!("I guessed {}, and I was right. I win on {} attempts!", computer_guess_number, guess_count);
    }
}

fn ask_for_user_input(message: &str) -> String {
    println!("{}", message);
    let mut input = String::new();
    io::stdin().read_line(&mut input).unwrap();
    let n:String = input.trim().parse().unwrap();
    return n;
}