use std::env;
use std::fs;

enum Mode {
	Info,
	Add,
	Remove,
}

fn main() {
	let mut mode = Mode::Info;

	for arg in env::args().skip(1) {
		match arg.as_str() {
			"--add" => { mode = Mode::Add; }
			"--remove" => { mode = Mode::Remove; }
			_ => { process_file(&arg, &mode); }
		}
	}
}

fn process_file(path: &str, mode: &Mode) {
	let mut content = fs::read_to_string(path).expect("could not read file");

	if ends_with_newline(&content) {
		match mode {
			Mode::Remove => {
				content.pop();
				fs::write(path, content).expect("could not write file");
				println!("\x1B[1m{}\x1B[0m: \x1B[31mno final newline [removed]\x1B[0m", path);
			}
			_ => {
				println!("\x1B[1m{}\x1B[0m: \x1B[32mfinal newline\x1B[0m", path);
			}
		}
	} else {
		match mode {
			Mode::Add => {
				content.push('\n');
				fs::write(path, content).expect("could not write file");
				println!("\x1B[1m{}\x1B[0m: \x1B[32mfinal newline [added]\x1B[0m", path);
			}
			_ => {
				println!("\x1B[1m{}\x1B[0m: \x1B[31mno final newline\x1B[0m", path);
			}
		}
	}
}

fn ends_with_newline(s: &str) -> bool {
	match s.chars().last() {
		Some('\n') => true,
		_ => false,
	}
}