tstreamerinfo.rs

use std::fmt::Debug;

use nom::{combinator::eof, multi::length_value, number::complete::*, IResult};

use quote::*;

use crate::{
    code_gen::rust::{ToNamedRustParser, ToRustParser, ToRustStruct, ToRustType},
    code_gen::utils::type_is_core,
    core::*,
};

#[derive(Debug)]
#[allow(dead_code)]
pub struct TStreamerInfo {
    tstreamerinfo_ver: u16,
    named: TNamed,
    checksum: u32,
    new_class_version: u32,
    data_members: Vec<TStreamer>,
}

/// Parse one `TStreamerInfo` object (as found in the `TList`)
pub(crate) fn tstreamerinfo<'s>(
    i: &'s [u8],
    context: &'s Context,
) -> IResult<&'s [u8], TStreamerInfo> {
    let parse_members = |i| tobjarray(|raw_obj, _context| tstreamer(raw_obj), i, context);

    let (i, tstreamerinfo_ver) = be_u16(i)?;
    let (i, named) = length_value(checked_byte_count, tnamed)(i)?;
    let (i, checksum) = be_u32(i)?;
    let (i, new_class_version) = be_u32(i)?;
    let (i, _size_tobjarray_with_class_info) = checked_byte_count(i)?;
    let (i, _class_info_objarray) = classinfo(i)?;
    let (i, data_members) = length_value(checked_byte_count, parse_members)(i)?;
    let (i, _eof) = eof(i)?;
    Ok((
        i,
        TStreamerInfo {
            tstreamerinfo_ver,
            named,
            checksum,
            new_class_version,
            data_members,
        },
    ))
}

impl ToRustParser for TStreamerInfo {
    /// Generate a parser that can parse an an object described by this TStreamer
    #[rustfmt::skip::macros(do_parse)]
    fn to_inline_parser(&self) -> Tokens {
        if type_is_core(self.named.name.as_str()) {
            // Don't generate a parser if its a core type
            return quote!(#(self.named.name.to_lowercase()));
        }
        let struct_name = Ident::new(self.named.name.as_str());
        let member_names: &Vec<Ident> =
            &self.data_members.iter().map(|m| m.member_name()).collect();
        let member_parsers: &Vec<Tokens> = &self
            .data_members
            .iter()
            .map(|m| m.to_inline_parser())
            .collect();
        quote! {
        do_parse!(ver: be_u16 >>
                  #(#member_names : #member_parsers >> )*
                  ({let phantom = PhantomData;
                    #struct_name {
                        phantom,
                        ver,
                        #(#member_names),*
                    }})
        )}
    }
}

impl ToNamedRustParser for TStreamerInfo {
    fn parser_name(&self) -> Tokens {
        let ret = Ident::new(self.named.name.to_lowercase());
        quote!(#ret)
    }

    fn to_named_parser(&self) -> Tokens {
        if type_is_core(self.named.name.as_str()) {
            // Don't generate a parser if its a core type
            return quote! {};
        }
        let parser_name = self.parser_name();
        let parser = self.to_inline_parser();
        let struct_name = self.type_name();
        quote! {
            pub fn #parser_name<'s>(input: &'s[u8], context: &'s Context<'s>)
                                    -> IResult<&'s[u8], #struct_name<'s>> {
                value!(input, #parser)
            }
        }
    }
}

impl ToRustStruct for TStreamerInfo {
    /// Generate a struct corresponding to this TStreamerInfo
    fn to_struct(&self) -> Tokens {
        if type_is_core(self.named.name.as_str()) {
            return quote! {};
        }
        let name = self.type_name();
        let fields = &self.data_members;
        let ver_comment = self.type_doc();
        quote! {
            #[derive(Debug)]
            pub struct #name<'s> {
                /// Gurantee that this object does not outlive its underlying slice
                phantom: PhantomData<&'s[u8]>,
                #ver_comment
                ver: u16,
                #(#fields), *
            }
        }
    }
}

impl ToRustType for TStreamerInfo {
    fn type_doc(&self) -> Tokens {
        let ret = Ident::new("\n/// Version of the read layout\n");
        quote!(#ret)
    }
    fn type_name(&self) -> Tokens {
        let ret = Ident::new(self.named.name.as_str());
        quote!(#ret)
    }
}

impl TStreamerInfo {
    pub(crate) fn to_yaml(&self) -> String {
        if type_is_core(self.named.name.as_str()) {
            return "".to_string();
        };
        let mut s = "".to_string();
        s += format!("{}:\n", self.named.name).as_str();
        s += format!("  version: {}\n", self.new_class_version).as_str();
        s += "  members:\n";
        for obj in &self.data_members {
            s += format!("      # {}\n", obj.member_comment()).as_str();
            s += format!("      {}: {}\n", obj.member_name(), obj.type_name()).as_str();
        }
        s += "\n";
        s
    }
}