1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145

//! Code generation for Fasters.
//!
//! # Warning!
//!
//! Fasters has been renamed to FerrumFIX. Go to
//! <https://github.com/neysofu/ferrum-fix> to find the new docs. **Don't use this
//! crate, use FerrumFIX instead!**
//! 
//! ---

#![deny(missing_debug_implementations, clippy::useless_conversion)]

use darling::{FromDeriveInput, FromField};
use proc_macro::TokenStream;
use proc_macro2::TokenStream as TokenStream2;
use quote::quote;

#[proc_macro_derive(TsrMessage, attributes(fasters))]
pub fn derive_tsr_message(input: TokenStream) -> TokenStream {
    let ast: syn::DeriveInput = syn::parse(input).unwrap();
    let darling_context = MessageStructure::from_derive_input(&ast).unwrap();
    let context = GeneratorContext {
        crate_path: CratePath::Relative,
        message_structure: darling_context,
    };
    let gen = context.gen_get_field();
    //gen.extend(context.gen_set_field());
    //gen.extend(context.gen_transforms());
    gen.into()
}

#[derive(Debug, Clone, FromField)]
#[darling(attributes(fasters))]
struct MessageStructureField {
    ident: Option<syn::Ident>,
    ty: syn::Type,
    tag: u32,
    opt: bool,
    rust_type: String,
}

#[derive(Debug, Clone, FromDeriveInput)]
#[darling(attributes(fasters), supports(struct_named))]
struct MessageStructure {
    ident: syn::Ident,
    data: darling::ast::Data<darling::util::Ignored, MessageStructureField>,
    msg_type: String,
}

enum CratePath {
    Absolute,
    Relative,
}

struct GeneratorContext {
    crate_path: CratePath,
    message_structure: MessageStructure,
}

impl GeneratorContext {
    fn crate_path(&self) -> TokenStream2 {
        match self.crate_path {
            CratePath::Absolute => quote! { ::fasters },
            CratePath::Relative => quote! { crate },
        }
    }

    fn gen_transforms(&self) -> TokenStream2 {
        let name = &self.message_structure.ident;
        let crate_name = self.crate_path();
        let gen = quote! {
            impl ::std::convert::TryFrom<#crate_name::slr::Message> for #name {
                type Error = ();

                fn try_from(msg: #crate_name::slr::Message) -> Result<Self, Self::Error> {
                    todo!();
                }
            }

            impl ::std::convert::From<#name> for #crate_name::slr::Message {
                fn from(msg: #(self.message_name)) -> Self {
                    let message = #crate_name::slr::Message::new();
                    message.fields.
                }
            }
        };
        gen
    }

    fn gen_set_field(&self) -> TokenStream2 {
        let name = &self.message_structure.ident;
        let crate_name = self.crate_path();
        let gen = quote! {
            impl #name {
                fn set_field(&mut self, tag: u32, value: ::std::option::Option<#crate_name::slr::FixValue>) {
                    match (tag, value) {
                        _ => todo!(),
                    }
                }
            }
        };
        gen
    }

    fn gen_get_field(&self) -> TokenStream2 {
        let crate_name = self.crate_path();
        let match_body = self
            .message_structure
            .data
            .clone()
            .map_struct_fields(|field| {
                let field_name = &field.ident.as_ref().unwrap();
                let field_tag = field.tag;
                if field.opt {
                    quote! {
                        #field_tag => self.#field_name.clone().map(|v| v.into())
                    }
                } else {
                    quote! {
                        #field_tag => ::std::option::Option::Some(self.#field_name.clone().into())
                    }
                }
            })
            .take_struct()
            .unwrap()
            .fields;
        let name = &self.message_structure.ident;
        let gen = quote! {
            impl #name {
                fn get_field(&self, tag: u32) -> ::std::option::Option<#crate_name::app::slr::FixFieldValue> {
                    match tag {
                        #(#match_body),*,
                        _ => None,
                    }
                }
            }
        };
        gen
    }
}

#[derive(Debug, Clone)]
enum Error {
    NotANamedStruct(String),
}