WIP: Complete work of propfind parsing

crates/xml/derive/src/xml_enum/mod.rs

@@ -0,0 +1,129 @@
+use super::{Variant, attrs::EnumAttrs};
+use crate::attrs::VariantAttrs;
+use core::panic;
+use darling::{FromDeriveInput, FromVariant};
+use quote::quote;
+use syn::{DataEnum, DeriveInput};
+
+mod impl_de;
+mod impl_prop_name;
+mod impl_se;
+
+pub struct Enum {
+    attrs: EnumAttrs,
+    variants: Vec<Variant>,
+    ident: syn::Ident,
+    generics: syn::Generics,
+}
+
+impl Enum {
+    pub fn parse(input: &DeriveInput, data: &DataEnum) -> Self {
+        let attrs = EnumAttrs::from_derive_input(input).unwrap();
+
+        Self {
+            variants: data
+                .variants
+                .iter()
+                .map(|variant| Variant {
+                    attrs: VariantAttrs::from_variant(variant).unwrap(),
+                    variant: variant.to_owned(),
+                })
+                .collect(),
+            attrs,
+            ident: input.ident.to_owned(),
+            generics: input.generics.to_owned(),
+        }
+    }
+
+    pub fn impl_xml_document(&self) -> proc_macro2::TokenStream {
+        if self.attrs.untagged.is_present() {
+            panic!("XmlDocument only supported for untagged enums");
+        }
+        let (impl_generics, type_generics, where_clause) = self.generics.split_for_impl();
+        let ident = &self.ident;
+
+        quote! {
+            impl #impl_generics ::rustical_xml::XmlDocument for #ident #type_generics #where_clause {
+                fn parse<R: ::std::io::BufRead>(mut reader: ::quick_xml::NsReader<R>) -> Result<Self, ::rustical_xml::XmlError>
+                where
+                    Self: ::rustical_xml::XmlDeserialize
+                {
+                    use ::quick_xml::events::Event;
+
+                    let mut buf = Vec::new();
+                    loop {
+                        let event = reader.read_event_into(&mut buf)?;
+                        let empty = matches!(event, Event::Empty(_));
+
+                        match event {
+                            Event::Start(start) | Event::Empty(start) => {
+                                return <Self as ::rustical_xml::XmlDeserialize>::deserialize(&mut reader, &start, empty);
+                            }
+                            Event::Eof => return Err(::rustical_xml::XmlError::Eof),
+                            Event::Text(bytes_text) => {
+                                return Err(::rustical_xml::XmlError::UnsupportedEvent("Text"));
+                            }
+                            Event::CData(cdata) => {
+                                return Err(::rustical_xml::XmlError::UnsupportedEvent("CDATA"));
+                            }
+                            Event::Decl(_) => { /* <?xml ... ?> ignore this */ }
+                            Event::Comment(_) => { /* ignore */ }
+                            Event::DocType(_) => { /* ignore */ }
+                            Event::PI(_) => {
+                                return Err(::rustical_xml::XmlError::UnsupportedEvent("Processing instruction"));
+                            }
+                            Event::End(end) => {
+                                unreachable!("Premature end of xml document, should be handled by quick_xml");
+                            }
+                        };
+                    }
+                }
+            }
+        }
+    }
+
+    pub fn impl_enum_variants(&self) -> proc_macro2::TokenStream {
+        let (impl_generics, type_generics, where_clause) = self.generics.split_for_impl();
+        let ident = &self.ident;
+
+        if self.attrs.untagged.is_present() {
+            let untagged_variants = self.variants.iter().map(|variant| {
+                let ty = &variant.deserializer_type();
+                quote! { #ty::variant_names() }
+            });
+            quote! {
+                impl #impl_generics ::rustical_xml::EnumVariants for #ident #type_generics #where_clause {
+                    const TAGGED_VARIANTS: &'static [(Option<::quick_xml::name::Namespace<'static>>, &'static str)] = &[];
+
+                    fn variant_names() -> Vec<(Option<::quick_xml::name::Namespace<'static>>, &'static str)> {
+                        [
+                            #(#untagged_variants),*
+                        ].concat()
+                    }
+                }
+            }
+        } else {
+            let tagged_variants = self.variants.iter().map(|variant| {
+                let ns = match &variant.attrs.common.ns {
+                    Some(ns) => quote! { Some(#ns) },
+                    None => quote! { None },
+                };
+                let b_xml_name = variant.xml_name().value();
+                let xml_name = String::from_utf8_lossy(&b_xml_name);
+                quote! {(#ns, #xml_name)}
+            });
+
+            quote! {
+                impl #impl_generics ::rustical_xml::EnumVariants for #ident #type_generics #where_clause {
+                    const TAGGED_VARIANTS: &'static [(Option<::quick_xml::name::Namespace<'static>>, &'static str)] = &[
+                        #(#tagged_variants),*
+                    ];
+
+                    fn variant_names() -> Vec<(Option<::quick_xml::name::Namespace<'static>>, &'static str)> {
+                        [Self::TAGGED_VARIANTS,].concat()
+                    }
+                }
+            }
+        }
+    }
+}