basic-computer-games/84_Super_Star_Trek/rust/src/main.rs

use std::{io::{stdin, stdout, Write}, process::exit, str::FromStr};

use model::Galaxy;

use crate::model::Condition;

mod model;
mod commands;

fn main() {
    ctrlc::set_handler(move || { exit(0) })
    .expect("Error setting Ctrl-C handler");

    let mut galaxy = Galaxy::generate_new();
    // todo: init options, starting state and notes
    commands::short_range_scan(&galaxy);

    loop {
        match prompt("Command?").to_uppercase().as_str() {
            "SRS" => commands::short_range_scan(&galaxy),
            "NAV" => gather_dir_and_speed_then_move(&mut galaxy),
            _ => print_command_help()
        }

        if galaxy.enterprise.condition == Condition::Destroyed { // todo: also check if stranded
            println!("Is is stardate {}.
            There were {} Klingon battle cruisers left at
            the end of your mission.
            ", galaxy.stardate, galaxy.remaining_klingons());
            break;
        }
    }
}

fn gather_dir_and_speed_then_move(galaxy: &mut Galaxy) {
    const BAD_NAV: &str = "   Lt. Sulu reports, 'Incorrect course data, sir!'";

    let course = prompt_value::<u8>("Course (1-9)?", 1, 9);
    if course.is_none() {
        println!("{}", BAD_NAV); 
        return;
    }

    let speed = prompt_value::<f32>("Warp Factor (0-8)?", 0.0, 8.0);
    if speed.is_none() {
        println!("{}", BAD_NAV); 
        return;
    }

    commands::move_klingons_and_fire(galaxy);
    if galaxy.enterprise.condition == Condition::Destroyed {
        return;
    }
    commands::move_enterprise(course.unwrap(), speed.unwrap(), galaxy);
}

fn prompt(prompt_text: &str) -> String {
    let stdin = stdin();
    let mut stdout = stdout();

    print!("{prompt_text} ");
    let _ = stdout.flush();

    let mut buffer = String::new();
    if let Ok(_) = stdin.read_line(&mut buffer) {
        return buffer.trim_end().into();
    }
    "".into()
}

fn prompt_value<T: FromStr + PartialOrd>(prompt_text: &str, min: T, max: T) -> Option<T> {
    let passed = prompt(prompt_text);
    match passed.parse::<T>() {
        Ok(n) if (n >= min && n <= max) => Some(n),
        _ => None
    }
}

fn print_command_help() {
    println!("Enter one of the following:
  NAV  (To set course)
  SRS  (For short range sensor scan)
  LRS  (For long range sensor scan)
  PHA  (To fire phasers)
  TOR  (To fire photon torpedoes)
  SHE  (To raise or lower shields)
  DAM  (For damage control reports)
  COM  (To call on library-computer)
  XXX  (To resign your command)
    ")
}