use std::fs;
use std::env;
use std::io;
use std::path::Path;

const HELP_MSG: &'static str = "\
FEJIX_CONFIG_PATH is not defined. \
Define it please so that I will know \
where to put the compiler's configuration and other important stuff";

const OBJECTS: &'static [&'static str] = &[
    "fejix_config.toml",
    "fejix_stdlib",
    "fejix_stdlib/core.fj",
    "fejix_stdlib/uibase.fj",
];

fn main() -> io::Result<()> {
    if let Ok(destination) = env::var("FEJIX_CONFIG_PATH") {
        let path = Path::new(&destination);
        
        if !path.exists() {
            fs::create_dir(&path)?;
        }

        if !path.is_dir() {
            panic!("Path is not a directory: {}", &destination);
        }

        for object_name in OBJECTS {
            let object_path = Path::new(object_name);

            let target_path = path.join(object_path);

            if target_path.exists() {
                continue;
            }

            if object_path.is_dir() {
                fs::create_dir(target_path)?;
            } else {
                fs::copy(object_path, target_path)?;
            }
        }

    } else {
        panic!("{}", HELP_MSG);
    }

    Ok(())
}