modi_macros 0.1.1

use crate::consts;
use crate::parser::{ get_modi_attribute, KeyValue, Parser };
use crate::structures::service::MetaData;
use syn::spanned::Spanned;
use syn::{ DeriveInput, Error, Type };

impl Parser<MetaData> for DeriveInput {
    fn parse_as(&self) -> syn::Result<MetaData> {
        // Find the modi(interface = ?) attribute
        let modi_attribute = get_modi_attribute(&self.attrs).ok_or_else(|| {
            Error::new(
                self.ident.span(),
                format!(
                    "Unable to find interface. Please add a '#[{}({} = <your trait>)]'",
                    consts::ATTR_NAME,
                    consts::INTERFACE_ATTR_NAME
                )
            )
        })?;

        // Get the interface key/value
        let interface_kv: KeyValue<Type> = modi_attribute
            .parse_args()
            .map_err(|_| {
                Error::new(
                    modi_attribute.span(),
                    format!(
                        "Invalid attribute format. The attribute must be in name-value form. \
                     Example: #[{}({} = <your trait>)]",
                        consts::ATTR_NAME,
                        consts::INTERFACE_ATTR_NAME
                    )
                )
            })?;

        if interface_kv.key != consts::INTERFACE_ATTR_NAME {
            return Err(
                Error::new(
                    self.ident.span(),
                    format!(
                        "Unable to find interface. Please add a '#[{}({} = <your trait>)]'",
                        consts::ATTR_NAME,
                        consts::INTERFACE_ATTR_NAME
                    )
                )
            );
        }

        Ok(MetaData {
            identifier: self.ident.clone(),
            generics: self.generics.clone(),
            interface: interface_kv.value,
            visibility: self.vis.clone(),
        })
    }
}