Fix(lua_macros): Expand to generate the required types and functions

lua_macros/Cargo.toml

@@ -4,9 +4,10 @@ version = "0.1.0"
 edition = "2021"
 
 [lib]
-crate_type = ["proc-macro"]
+proc-macro = true
 
 [dependencies]
+convert_case = "0.6.0"
 proc-macro2 = "1.0.64"
 quote = "1.0.29"
-syn = "2.0.25"
+syn = { version = "2.0.25", features = ["extra-traits", "full", "parsing"] }

lua_macros/src/generate_noop_lua_function.rs

@@ -0,0 +1,11 @@
+use proc_macro2::TokenStream as TokenStream2;
+use quote::ToTokens;
+
+// TODO: Do we need this noop?
+pub fn generate_default_lua_function(input: &syn::Field) -> TokenStream2 {
+    let output: TokenStream2 = syn::parse(input.into_token_stream().into())
+        .expect("This is generated from valid rust code, it should stay that way.");
+
+    output
+}
+

lua_macros/src/lib.rs

@@ -1,59 +1,68 @@
+mod generate_noop_lua_function;
+mod mark_as_ci_command;
+mod struct_to_ci_enum;
+
+use generate_noop_lua_function::generate_default_lua_function;
+use mark_as_ci_command::generate_final_function;
 use proc_macro::TokenStream;
 use proc_macro2::TokenStream as TokenStream2;
-use quote::{format_ident, quote};
+use quote::quote;
-use syn;
+use struct_to_ci_enum::{generate_command_enum, generate_generate_ci_function};
+use syn::{self, ItemFn, Field, parse::Parser};
 
 #[proc_macro_attribute]
-pub fn generate_ci_functions(_: TokenStream, input: TokenStream) -> TokenStream {
+pub fn turn_struct_to_ci_commands(_attrs: TokenStream, input: TokenStream) -> TokenStream {
     // Construct a representation of Rust code as a syntax tree
     // that we can manipulate
     let input = syn::parse(input)
         .expect("This should always be valid rust code, as it's extracted from direct code");
 
     // Build the trait implementation
-    generate_generate_ci_functions(&input)
+    let generate_ci_function: TokenStream2 = generate_generate_ci_function(&input);
-}
+
+    let command_enum = generate_command_enum(&input);
 
-fn generate_generate_ci_functions(input: &syn::DeriveInput) -> TokenStream {
-    let input_tokens: TokenStream2 = match &input.data {
-        syn::Data::Struct(input) => match &input.fields {
-            syn::Fields::Named(named_fields) => named_fields
-                .named
-                .iter()
-                .map(|field| -> TokenStream2 {
-                    let field_ident = field.ident.as_ref().expect(
-                        "These are only the named field, thus they all should have a name.",
-                    );
-                    let function_name_ident = format_ident!("fun_{}", field_ident);
-                    let function_name = format!("{}", field_ident);
     quote! {
-                        let #function_name_ident = context.create_function(#field_ident).expect(
+        #command_enum
-                            &format!(
+        #generate_ci_function
-                                "The function: `{}` should be defined",
+    }
-                                #function_name
+    .into()
-                            )
+}
-                        );
+
-                        globals.set(#function_name, #function_name_ident).expect(
+/// Generate a default lua function implementation.
-                            &format!(
+#[proc_macro_attribute]
-                                "Setting a static global value ({}, fun_{}) should work",
+pub fn gen_lua_function(_attrs: TokenStream, input: TokenStream) -> TokenStream {
-                                #function_name,
+    // Construct a representation of Rust code as a syntax tree
-                                #function_name
+    // that we can manipulate
-                                )
+    //
-                        );
+    let parser = Field::parse_named;
+    let input = parser.parse(input)
+        .expect("This is only defined for named fileds.");
+
+
+    // Build the trait implementation
+    let default_lua_function: TokenStream2 = generate_default_lua_function(&input);
+
+    quote! {
+        #default_lua_function
+    }
+    .into()
+}
+
+/// Turn a function into a valid ci command function
+#[proc_macro_attribute]
+pub fn ci_command(_attrs: TokenStream, input: TokenStream) -> TokenStream {
+    // Construct a representation of Rust code as a syntax tree
+    // that we can manipulate
+    let mut input: ItemFn = syn::parse(input)
+        .expect("This should always be valid rust code, as it's extracted from direct code");
+
+    // Build the trait implementation
+    let output_function: TokenStream2 = generate_final_function(&mut input);
+
+    //panic!("{:#?}", output_function);
+    quote! {
+        #output_function
     }
     .into()
-                })
-                .collect(),
-            _ => unimplemented!("Only implemented for named fileds"),
-        },
-        _ => unimplemented!("Only for implemented for structs"),
-    };
-
-    let gen = quote! {
-        pub fn generate_ci_functions(context: &mut Context) {
-            let globals = context.globals();
-            #input_tokens
-        }
-    };
-    gen.into()
 }

lua_macros/src/mark_as_ci_command.rs

@@ -0,0 +1,161 @@
+use convert_case::{Case, Casing};
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{format_ident, quote, ToTokens};
+use syn::{Block, Expr, ExprBlock, GenericArgument, ReturnType, Stmt, Type};
+
+pub fn generate_final_function(input: &mut syn::ItemFn) -> TokenStream2 {
+    append_tx_send_code(input);
+
+    let output: TokenStream2 = syn::parse(input.into_token_stream().into())
+        .expect("This is generated from valid rust code, it should stay that way.");
+
+    output
+}
+
+fn append_tx_send_code(input: &mut syn::ItemFn) -> &mut syn::ItemFn {
+    let function_name_pascal = format_ident!(
+        "{}",
+        input
+            .sig
+            .ident
+            .clone()
+            .to_string()
+            .from_case(Case::Snake)
+            .to_case(Case::Pascal)
+    );
+
+    let tx_send = match &input.sig.output {
+        syn::ReturnType::Default => {
+            todo!(
+            "Does this case even trigger? All functions should have a output of (Result<$type, rlua::Error>)"
+            );
+            quote! {
+                {
+                    let tx: std::sync::mpsc::Sender<crate::app::events::event_types::Event> =
+                    context
+                        .named_registry_value("sender_for_ci_commands")
+                        .expect("This exists, it was set before");
+
+                    tx
+                    .send(Event::CommandEvent(Command::#function_name_pascal))
+                    .expect("This should work, as the reciever is not dropped");
+                }
+            }
+        }
+        syn::ReturnType::Type(_, ret_type) => {
+            let return_type = match *(ret_type.clone()) {
+                syn::Type::Path(path) => {
+                    match path
+                        .path
+                        .segments
+                        .first()
+                        .expect("This is expected to be only one path segment")
+                        .arguments
+                        .to_owned()
+                    {
+                        syn::PathArguments::AngleBracketed(angled_path) => {
+                            let angled_path = angled_path.args.to_owned();
+                            let filtered_paths: Vec<_> = angled_path
+                                .into_iter()
+                                .filter(|generic_arg| {
+                                    if let GenericArgument::Type(generic_type) = generic_arg {
+                                        if let Type::Path(_) = generic_type {
+                                            true
+                                        } else {
+                                            false
+                                        }
+                                    } else {
+                                        false
+                                    }
+                                })
+                                .collect();
+
+                            // There should only be two segments (the type is <String, rlua::Error>)
+                            if filtered_paths.len() > 2 {
+                                unreachable!(
+                                    "There should be no more than two filtered_output, but got: {:#?}",
+                                    filtered_paths
+                                )
+                            } else if filtered_paths.len() <= 0 {
+                                unreachable!(
+                                    "There should be more than zero filtered_output, but got: {:#?}",
+                                    filtered_paths
+                                )
+                            }
+                            if filtered_paths.len() == 2 {
+                                // There is something else than rlua
+                                let gen_type = if let GenericArgument::Type(ret_type) =
+                                    filtered_paths
+                                        .first()
+                                        .expect("One path segment should exists")
+                                        .to_owned()
+                                {
+                                    ret_type
+                                } else {
+                                    unreachable!("These were filtered above.");
+                                };
+                                let return_type_as_type_prepared = quote! {-> #gen_type};
+
+                                let return_type_as_return_type: ReturnType = syn::parse(
+                                    return_type_as_type_prepared.to_token_stream().into(),
+                                )
+                                .expect("This is valid.");
+                                return_type_as_return_type
+                            } else {
+                                // There is only rlua
+                                ReturnType::Default
+                            }
+                        }
+                        _ => unimplemented!("Only for angled paths"),
+                    }
+                }
+                _ => unimplemented!("Only for path types"),
+            };
+            match return_type {
+                ReturnType::Default => {
+                    quote! {
+                        {
+                            let tx: std::sync::mpsc::Sender<crate::app::events::event_types::Event> =
+                            context
+                                .named_registry_value("sender_for_ci_commands")
+                                .expect("This exists, it was set before");
+
+                            tx
+                            .send(Event::CommandEvent(Command::#function_name_pascal))
+                            .expect("This should work, as the reciever is not dropped");
+                        }
+                    }
+                }
+                ReturnType::Type(_, _) => {
+                    quote! {
+                        {
+                            let tx: std::sync::mpsc::Sender<crate::app::events::event_types::Event> =
+                            context
+                                .named_registry_value("sender_for_ci_commands")
+                                .expect("This exists, it was set before");
+
+                            tx
+                            .send(Event::CommandEvent(Command::#function_name_pascal(input_str)))
+                            .expect("This should work, as the reciever is not dropped");
+                        }
+                    }
+                }
+            }
+        }
+    };
+
+    let tx_send_block: Block =
+        syn::parse(tx_send.into()).expect("This is a static string, it will always parse");
+    let tx_send_expr_block = ExprBlock {
+        attrs: vec![],
+        label: None,
+        block: tx_send_block,
+    };
+    let mut tx_send_stmt = vec![Stmt::Expr(Expr::Block(tx_send_expr_block), None)];
+
+    let mut new_stmts: Vec<Stmt> = Vec::with_capacity(input.block.stmts.len() + 1);
+    new_stmts.append(&mut tx_send_stmt);
+    new_stmts.append(&mut input.block.stmts);
+    input.block.stmts = new_stmts;
+    input
+}

lua_macros/src/struct_to_ci_enum.rs

@@ -0,0 +1,140 @@
+use convert_case::{Case, Casing};
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{format_ident, quote};
+use syn::{self, ReturnType};
+
+pub fn generate_generate_ci_function(input: &syn::DeriveInput) -> TokenStream2 {
+    let mut functions_to_generate: Vec<TokenStream2> = vec![];
+    let input_tokens: TokenStream2 = match &input.data {
+        syn::Data::Struct(input) => match &input.fields {
+            syn::Fields::Named(named_fields) => named_fields
+                .named
+                .iter()
+                .map(|field| -> TokenStream2 {
+                    if field.attrs.iter().any(|attribute| {
+                        attribute.path()
+                            == &syn::parse_str::<syn::Path>("gen_default_lua_function")
+                                .expect("This is valid rust code")
+                    }) {
+                        let function_name = field
+                            .ident
+                            .as_ref()
+                            .expect("These are only the named field, thus they all should have a name.");
+                        functions_to_generate.push(quote! {
+                            #[ci_command]
+                            fn #function_name(context: Context, input_str: String) -> Result<(), rlua::Error> {
+                                Ok(())
+                        }
+                                                });
+                        generate_ci_part(field)
+                    } else {
+                        generate_ci_part(field)
+                    }
+                })
+                .collect(),
+
+            _ => unimplemented!("Only implemented for named fileds"),
+        },
+        _ => unimplemented!("Only implemented for structs"),
+    };
+
+    let functions_to_generate: TokenStream2 = functions_to_generate.into_iter().collect();
+    let gen = quote! {
+        pub fn generate_ci_functions(
+            context: &mut rlua::Context,
+            tx: std::sync::mpsc::Sender<crate::app::events::event_types::Event>)
+        {
+            context.set_named_registry_value("sender_for_ci_commands", tx).expect("This should always work, as the value is added before all else");
+            let globals = context.globals();
+            #input_tokens
+        }
+        #functions_to_generate
+    };
+    gen.into()
+}
+
+fn generate_ci_part(field: &syn::Field) -> TokenStream2 {
+    let field_ident = field
+        .ident
+        .as_ref()
+        .expect("These are only the named field, thus they all should have a name.");
+    let function_name_ident = format_ident!("fun_{}", field_ident);
+    let function_name = format!("{}", field_ident);
+    quote! {
+        let #function_name_ident = context.create_function(#field_ident).expect(
+            &format!(
+                "The function: `{}` should be defined",
+                #function_name
+            )
+        );
+
+        globals.set(#function_name, #function_name_ident).expect(
+            &format!(
+                "Setting a static global value ({}, fun_{}) should work",
+                #function_name,
+                #function_name
+                )
+        );
+    }
+    .into()
+}
+
+pub fn generate_command_enum(input: &syn::DeriveInput) -> TokenStream2 {
+    let input_tokens: TokenStream2 = match &input.data {
+        syn::Data::Struct(input) => match &input.fields {
+            syn::Fields::Named(named_fields) => named_fields
+                .named
+                .iter()
+                .map(|field| -> TokenStream2 {
+                    let field_ident = field
+                        .ident
+                        .as_ref()
+                        .expect("These are only the named field, thus they all should have a name.");
+
+                    let enum_variant_type = match &field.ty {
+                        syn::Type::BareFn(function) => {
+                            let return_path: &ReturnType = &function.output;
+                            match return_path {
+                                ReturnType::Default => None,
+                                ReturnType::Type(_, return_type) => Some(match *(return_type.to_owned()) {
+                                    syn::Type::Path(path_type) => path_type
+                                        .path
+                                        .get_ident()
+                                        .expect("A path should either be complete, or only conain one segment")
+                                        .to_owned(),
+                                    _ => unimplemented!("This is only implemented for path types"),
+                                }),
+                            }
+                        }
+                        _ => unimplemented!("This is only implemented for bare function types"),
+                    };
+
+                    let enum_variant_name = format_ident!(
+                        "{}",
+                        field_ident.to_string().from_case(Case::Snake).to_case(Case::Pascal)
+                    );
+                    if enum_variant_type.is_some() {
+                        quote! {
+                            #enum_variant_name (#enum_variant_type),
+                        }
+                        .into()
+                    } else {
+                        quote! {
+                            #enum_variant_name,
+                        }
+                    }
+                })
+                .collect(),
+            _ => unimplemented!("Only implemented for named fileds"),
+        },
+        _ => unimplemented!("Only implemented for structs"),
+    };
+
+    let gen = quote! {
+        #[derive(Debug)]
+        pub enum Command {
+            #input_tokens
+        }
+    };
+    gen.into()
+}