fn main() {

    let mut args = std::env::args();

    let json_ld_path = args.nth(1).expect("Missing jsonld file.");

    let context_path = args.next();

    if let Some(context_path) = &context_path {

        println!(

            "Loading {} with @context from {}",

            json_ld_path, context_path

        );

    } else {

        println!("Loading {}", json_ld_path);

    }

    let json_str = std::fs::read_to_string(&json_ld_path)

        .expect(&format!("Could not read file {}.", json_ld_path));

    let mut options = create_options();

    if let Some(context_path) = context_path {

        let context_str = std::fs::read_to_string(&context_path)

            .expect(&format!("Could not read file {}.", context_path));

        let context = create_context(&context_str);

        options = options.with_expand_context::<()>(context);

    }

    let parser = create_parser(options);

    parse(&json_str, parser);

}

fn create_context(context_str: &str) -> ContextRef {

    use json_ld::syntax::Parse;

    let vdoc = json_ld::syntax::Value::parse_str(context_str, |span| span).unwrap();

    let mdoc: Meta<_, _> = todo!();

fn create_options<I, M, T>() -> JsonLdOptions<DefaultLoaderFactory<NoLoader<I, M, T>>> {

    JsonLdOptions::<DefaultLoaderFactory<NoLoader<I, M, T>>>::default()

}

fn create_parser<LF>(options: JsonLdOptions<LF>) -> JsonLdParser<LF> {

    JsonLdParser::<LF>::new_with_options(options)

}

fn parse<LF>(json_str: &str, parser: JsonLdParser<LF>)

where

    LF: LoaderFactory,

{

    let graph = LightGraph::from_triple_source(parser.parse_str(json_str).to_triples()).unwrap();

    let mut stringifier =

        TurtleSerializer::new_stringifier_with_config(TurtleConfig::new().with_pretty(true));

    let rdf = stringifier.serialize_graph(&graph).unwrap().as_str();

    println!("{}", rdf);

}