use devise::Result;

use crate::syn::{Path, punctuated::Punctuated, parse::Parser, Token};
use crate::proc_macro2::TokenStream;
use crate::syn::spanned::Spanned;

mod uri;
mod uri_parsing;
mod test_guide;

fn struct_maker_vec(
    input: proc_macro::TokenStream,
    ty: TokenStream,
) -> Result<TokenStream> {
    use crate::exports::_Vec;

    // Parse a comma-separated list of paths.
    let paths = <Punctuated<Path, Token![,]>>::parse_terminated.parse(input)?;
    let exprs = paths.iter()
        .map(|path| quote_spanned!(path.span() => {
            let ___struct = #path {};
            let ___item: #ty = ___struct.into();
            ___item
        }));

    Ok(quote!({
        let ___vec: #_Vec<#ty> = vec![#(#exprs),*];
        ___vec
    }))
}

pub fn routes_macro(input: proc_macro::TokenStream) -> TokenStream {
    struct_maker_vec(input, quote!(::rocket::Route))
        .unwrap_or_else(|diag| diag.emit_as_expr_tokens())
}

pub fn catchers_macro(input: proc_macro::TokenStream) -> TokenStream {
    struct_maker_vec(input, quote!(::rocket::Catcher))
        .unwrap_or_else(|diag| diag.emit_as_expr_tokens())
}

pub fn uri_macro(input: proc_macro::TokenStream) -> TokenStream {
    uri::_uri_macro(input.into())
        .unwrap_or_else(|diag| diag.emit_as_expr_tokens())
}

pub fn uri_internal_macro(input: proc_macro::TokenStream) -> TokenStream {
    // FIXME: Ideally we would generate an `Origin::dummy()` so that we don't
    // assist in propoagate further errors. Alas, we can't set the span to the
    // invocation of `uri!` without access to `span.parent()`, and
    // `Span::call_site()` here points to the `#[route]`, immediate caller,
    // generate a rather confusing error message when there's a type-mismatch.
    // uri::_uri_internal_macro(input.into())
    //     .unwrap_or_else(|diag| diag.emit_as_expr_tokens_or(quote_spanned! { span =>
    //         rocket::http::uri::Origin::dummy()
    //     }))

    uri::_uri_internal_macro(input.into())
        .unwrap_or_else(|diag| diag.emit_as_expr_tokens())
}

pub fn guide_tests_internal(input: proc_macro::TokenStream) -> TokenStream {
    test_guide::_macro(input)
        .unwrap_or_else(|diag| diag.emit_as_item_tokens())
}