use crate::prelude::*;

use std::fs::{File, OpenOptions};
use std::io::Write;

pub type FileOpenFn = Box<dyn Fn(&str) -> Result<File>>;

pub type FileAppendLineFn = Box<dyn Fn(&str, &str) -> Result<()>>;

pub struct FileEnv {
    pub open: FileOpenFn,
    pub append_line: FileAppendLineFn,
}
impl Default for FileEnv {
    fn default() -> Self {
        Self {
            open: Box::new(|path| Ok(File::open(path)?)),
            append_line: Box::new(|file_name, line| {
                let mut file = OpenOptions::new()
                    .write(true)
                    .append(true)
                    .create(true)
                    .open(file_name)
                    .unwrap();
                writeln!(file, "{}", line)?;
                Ok(())
            }),
        }
    }
}