use std::path::PathBuf;
use std::{env, error::Error};

fn main() -> Result<(), Box<dyn Error>> {
    enum Device {
        NanoS,
        NanoSPlus,
        NanoX,
        Stax,
        Flex,
    }
    use Device::*;

    // determine device
    let device = match env::var_os("CARGO_CFG_TARGET_OS").unwrap().to_str().unwrap() {
        "nanos" => NanoS,
        "nanosplus" => NanoSPlus,
        "nanox" => NanoX,
        "stax" => Stax,
        "flex" => Flex,
        target_name => panic!(
            "invalid target `{target_name}`, expected one of `nanos`, `nanox`, `nanosplus`, `stax` or `flex`. Run with `-Z build-std=core --target=./<target name>.json`"
        ),
    };

    // Copy this crate's linker script into the working directory of
    // the application so that it can be used there for the layout.
    // Trick taken from https://docs.rust-embedded.org/embedonomicon/main.html
    let out_dir = PathBuf::from(env::var_os("OUT_DIR").unwrap());

    // extend the library search path
    println!("cargo:rustc-link-search={}", out_dir.display());
    // copy
    let linkerscript = match device {
        NanoS => "nanos_layout.ld",
        NanoX => "nanox_layout.ld",
        NanoSPlus => "nanosplus_layout.ld",
        Stax | Flex => "stax_flex_layout.ld",
    };
    std::fs::copy(linkerscript, out_dir.join(linkerscript))?;
    std::fs::copy("link.ld", out_dir.join("link.ld"))?;
    Ok(())
}