use std::env;
use std::fs;
use std::path::{Path, PathBuf};

fn copy<U: AsRef<Path>, V: AsRef<Path>>(from: U, to: V) -> std::io::Result<()> {
    let mut stack = vec![PathBuf::from(from.as_ref())];

    let output_root = PathBuf::from(to.as_ref());
    let input_root = PathBuf::from(from.as_ref()).components().count();

    while let Some(working_path) = stack.pop() {
        // Generate a relative path
        let src: PathBuf = working_path.components().skip(input_root).collect();

        // Create a destination if missing
        let dest = if src.components().count() == 0 {
            output_root.clone()
        } else {
            output_root.join(&src)
        };
        if fs::metadata(&dest).is_err() {
            fs::create_dir_all(&dest)?;
        }

        for entry in fs::read_dir(working_path)? {
            let entry = entry?;
            let path = entry.path();
            if path.is_dir() {
                stack.push(path);
            } else if let Some(filename) = path.file_name() {
                let dest_path = dest.join(filename);
                fs::copy(&path, &dest_path)?;
            }
        }
    }

    Ok(())
}

#[allow(unused_must_use)]
fn main() -> std::io::Result<()> {
    let install_path = dirs::config_dir()
        .expect("Couldn't find a configuration directory to install to.")
        .join("dttyper");
    fs::create_dir_all(&install_path);

    let resources_path = env::current_dir()
        .expect("Couldn't find the source directory.")
        .join("resources")
        .join("runtime");
    copy(resources_path, &install_path);

    Ok(())
}