use std::{
    fs::File,
    io::{BufReader, Read, StdinLock},
    path::PathBuf,
};

use crate::Result;

#[derive(Debug)]
pub enum Input {
    Stdin,
    File(PathBuf),
}

impl From<&str> for Input {
    fn from(value: &str) -> Self {
        Self::File(PathBuf::from(value))
    }
}

impl Input {
    pub(crate) fn reader(self) -> Result<InputReader<'static>> {
        Ok(match self {
            Input::File(p) => InputReader::File(BufReader::new(File::open(p)?)),
            Input::Stdin => InputReader::Stdin(std::io::stdin().lock()),
        })
    }
}

#[derive(Debug)]
pub enum InputReader<'a> {
    Stdin(StdinLock<'a>),
    File(BufReader<File>),
}

impl Read for InputReader<'_> {
    fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
        match self {
            InputReader::Stdin(s) => s.read(buf),
            InputReader::File(p) => p.read(buf),
        }
    }
}