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Diffstat (limited to 'systems/action/action_macros/src/lib.rs')
| -rw-r--r-- | systems/action/action_macros/src/lib.rs | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/systems/action/action_macros/src/lib.rs b/systems/action/action_macros/src/lib.rs new file mode 100644 index 0000000..e6616b4 --- /dev/null +++ b/systems/action/action_macros/src/lib.rs @@ -0,0 +1,248 @@ +use proc_macro::TokenStream; +use quote::quote; +use syn::{ItemFn, parse_macro_input}; + +/// # Macro - Generate Action +/// +/// When annotating a function with the `#[action_gen]` macro in the following format, it generates boilerplate code for client-server interaction +/// +/// ```ignore +/// #[action_gen] +/// async fn action_name(ctx: ActionContext, argument: YourArgument) -> Result<YourResult, TcpTargetError> { +/// // Write your client and server logic here +/// if ctx.is_proc_on_remote() { +/// // Server logic +/// } +/// if ctx.is_proc_on_local() { +/// // Client logic +/// } +/// } +/// ``` +/// +/// > WARNING: +/// > For Argument and Result types, the `action_gen` macro only supports types that derive serde's Serialize and Deserialize +/// +/// ## Generated Code +/// +/// `action_gen` will generate the following: +/// +/// 1. Complete implementation of Action<Args, Return> +/// 2. Process / Register method +/// +/// ## How to use +/// +/// You can use your generated method as follows +/// +/// ```ignore +/// async fn main() -> Result<(), TcpTargetError> { +/// +/// // Prepare your argument +/// let args = YourArgument::default(); +/// +/// // Create a pool and context +/// let mut pool = ActionPool::new(); +/// let ctx = ActionContext::local(); +/// +/// // Register your action +/// register_your_action(&mut pool); +/// +/// // Process your action +/// proc_your_action(&pool, ctx, args).await?; +/// +/// Ok(()) +/// } +/// ``` +#[proc_macro_attribute] +pub fn action_gen(attr: TokenStream, item: TokenStream) -> TokenStream { + let input_fn = parse_macro_input!(item as ItemFn); + let is_local = if attr.is_empty() { + false + } else { + let attr_str = attr.to_string(); + attr_str == "local" || attr_str.contains("local") + }; + + generate_action_struct(input_fn, is_local).into() +} + +fn generate_action_struct(input_fn: ItemFn, _is_local: bool) -> proc_macro2::TokenStream { + let fn_vis = &input_fn.vis; + let fn_sig = &input_fn.sig; + let fn_name = &fn_sig.ident; + let fn_block = &input_fn.block; + + validate_function_signature(fn_sig); + + let (context_param_name, arg_param_name, arg_type, return_type) = + extract_parameters_and_types(fn_sig); + + let struct_name = quote::format_ident!("{}", convert_to_pascal_case(&fn_name.to_string())); + + let action_name_ident = &fn_name; + + let register_this_action = quote::format_ident!("register_{}", action_name_ident); + let proc_this_action = quote::format_ident!("proc_{}", action_name_ident); + + quote! { + #[derive(Debug, Clone, Default)] + #fn_vis struct #struct_name; + + impl action_system::action::Action<#arg_type, #return_type> for #struct_name { + fn action_name() -> &'static str { + Box::leak(string_proc::snake_case!(stringify!(#action_name_ident)).into_boxed_str()) + } + + fn is_remote_action() -> bool { + !#_is_local + } + + async fn process(#context_param_name: action_system::action::ActionContext, #arg_param_name: #arg_type) -> Result<#return_type, tcp_connection::error::TcpTargetError> { + #fn_block + } + } + + #fn_vis fn #register_this_action(pool: &mut action_system::action_pool::ActionPool) { + pool.register::<#struct_name, #arg_type, #return_type>(); + } + + #fn_vis async fn #proc_this_action( + pool: &action_system::action_pool::ActionPool, + mut ctx: action_system::action::ActionContext, + #arg_param_name: #arg_type + ) -> Result<#return_type, tcp_connection::error::TcpTargetError> { + ctx.set_is_remote_action(!#_is_local); + let args_json = serde_json::to_string(&#arg_param_name) + .map_err(|e| { + tcp_connection::error::TcpTargetError::Serialization(e.to_string()) + })?; + let result_json = pool.process_json( + Box::leak(string_proc::snake_case!(stringify!(#action_name_ident)).into_boxed_str()), + ctx, + args_json, + ).await?; + serde_json::from_str(&result_json) + .map_err(|e| { + tcp_connection::error::TcpTargetError::Serialization(e.to_string()) + }) + } + + #[allow(dead_code)] + #[deprecated = "This function is used by #[action_gen] as a template."] + #[doc = "Template function for #[[action_gen]] - do not call directly."] + #[doc = "Use the generated struct instead."] + #[doc = ""] + #[doc = "Register the action to the pool."] + #[doc = "```ignore"] + #[doc = "register_your_func(&mut pool);"] + #[doc = "```"] + #[doc = ""] + #[doc = "Process the action at the pool."] + #[doc = "```ignore"] + #[doc = "let result = proc_your_func(&pool, ctx, arg).await?;"] + #[doc = "```"] + #fn_vis #fn_sig #fn_block + } +} + +fn validate_function_signature(fn_sig: &syn::Signature) { + if fn_sig.asyncness.is_none() { + panic!("Expected async function for Action, but found synchronous function"); + } + + if fn_sig.inputs.len() != 2 { + panic!( + "Expected exactly 2 arguments for Action function: ctx: ActionContext and arg: T, but found {} arguments", + fn_sig.inputs.len() + ); + } + + let return_type = match &fn_sig.output { + syn::ReturnType::Type(_, ty) => ty, + _ => panic!( + "Expected Action function to return Result<T, TcpTargetError>, but found no return type" + ), + }; + + if let syn::Type::Path(type_path) = return_type.as_ref() { + if let Some(segment) = type_path.path.segments.last() + && segment.ident != "Result" + { + panic!( + "Expected Action function to return Result<T, TcpTargetError>, but found different return type" + ); + } + } else { + panic!( + "Expected Action function to return Result<T, TcpTargetError>, but found no return type" + ); + } +} + +fn convert_to_pascal_case(s: &str) -> String { + s.split('_') + .map(|word| { + let mut chars = word.chars(); + match chars.next() { + None => String::new(), + Some(first) => first.to_uppercase().collect::<String>() + chars.as_str(), + } + }) + .collect() +} + +fn extract_parameters_and_types( + fn_sig: &syn::Signature, +) -> ( + proc_macro2::TokenStream, + proc_macro2::TokenStream, + proc_macro2::TokenStream, + proc_macro2::TokenStream, +) { + let mut inputs = fn_sig.inputs.iter(); + + let context_param = match inputs.next() { + Some(syn::FnArg::Typed(pat_type)) => { + let pat = &pat_type.pat; + quote::quote!(#pat) + } + _ => { + panic!("Expected the first argument to be a typed parameter, but found something else") + } + }; + + let arg_param = match inputs.next() { + Some(syn::FnArg::Typed(pat_type)) => { + let pat = &pat_type.pat; + let ty = &pat_type.ty; + (quote::quote!(#pat), quote::quote!(#ty)) + } + _ => { + panic!("Expected the second argument to be a typed parameter, but found something else") + } + }; + + let (arg_param_name, arg_type) = arg_param; + + let return_type = match &fn_sig.output { + syn::ReturnType::Type(_, ty) => { + if let syn::Type::Path(type_path) = ty.as_ref() { + if let syn::PathArguments::AngleBracketed(args) = + &type_path.path.segments.last().unwrap().arguments + { + if let Some(syn::GenericArgument::Type(ty)) = args.args.first() { + quote::quote!(#ty) + } else { + panic!("Expected to extract the success type of Result, but failed"); + } + } else { + panic!("Expected Result type to have generic parameters, but found none"); + } + } else { + panic!("Expected return type to be Result, but found different type"); + } + } + _ => panic!("Expected function to have return type, but found none"), + }; + + (context_param, arg_param_name, arg_type, return_type) +} |