1 files changed, 89 insertions, 0 deletions
diff --git a/src/severity.rs b/src/severity.rs
new file mode 100644
index 0000000..76126de
--- /dev/null
+++ b/src/severity.rs
@@ -0,0 +1,89 @@
+use proc_macro2::{Span, TokenStream};
+use quote::quote;
+use syn::{
+    parenthesized,
+    parse::{Parse, ParseStream},
+    Token,
+};
+
+use crate::{
+    diagnostic::{DiagnosticConcreteArgs, DiagnosticDef},
+    forward::WhichFn,
+    utils::gen_all_variants_with,
+};
+
+pub struct Severity(pub syn::Ident);
+
+impl Parse for Severity {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let ident = input.parse::<syn::Ident>()?;
+        if ident == "severity" {
+            let la = input.lookahead1();
+            if la.peek(syn::token::Paren) {
+                let content;
+                parenthesized!(content in input);
+                let la = content.lookahead1();
+                if la.peek(syn::LitStr) {
+                    let str = content.parse::<syn::LitStr>()?;
+                    let sev = get_severity(&str.value(), str.span())?;
+                    Ok(Severity(syn::Ident::new(&sev, str.span())))
+                } else {
+                    let ident = content.parse::<syn::Ident>()?;
+                    let sev = get_severity(&ident.to_string(), ident.span())?;
+                    Ok(Severity(syn::Ident::new(&sev, ident.span())))
+                }
+            } else {
+                input.parse::<Token![=]>()?;
+                let str = input.parse::<syn::LitStr>()?;
+                let sev = get_severity(&str.value(), str.span())?;
+                Ok(Severity(syn::Ident::new(&sev, str.span())))
+            }
+        } else {
+            Err(syn::Error::new(
+                ident.span(),
+                "MIETTE BUG: not a severity option",
+            ))
+        }
+    }
+}
+
+fn get_severity(input: &str, span: Span) -> syn::Result<String> {
+    match input.to_lowercase().as_ref() {
+        "error" | "err" => Ok("Error".into()),
+        "warning" | "warn" => Ok("Warning".into()),
+        "advice" | "adv" | "info" => Ok("Advice".into()),
+        _ => Err(syn::Error::new(
+            span,
+            "Invalid severity level. Only Error, Warning, and Advice are supported.",
+        )),
+    }
+}
+
+impl Severity {
+    pub(crate) fn gen_enum(variants: &[DiagnosticDef]) -> Option<TokenStream> {
+        gen_all_variants_with(
+            variants,
+            WhichFn::Severity,
+            |ident, fields, DiagnosticConcreteArgs { severity, .. }| {
+                let severity = &severity.as_ref()?.0;
+                let fields = match fields {
+                    syn::Fields::Named(_) => quote! { { .. } },
+                    syn::Fields::Unnamed(_) => quote! { (..) },
+                    syn::Fields::Unit => quote! {},
+                };
+                Some(
+                    quote! { Self::#ident #fields => std::option::Option::Some(miette::Severity::#severity), },
+                )
+            },
+        )
+    }
+
+    pub(crate) fn gen_struct(&self) -> Option<TokenStream> {
+        let sev = &self.0;
+        Some(quote! {
+            fn severity(&self) -> std::option::Option<miette::Severity> {
+                Some(miette::Severity::#sev)
+            }
+        })
+    }
+}