114 lines
4.5 KiB
Rust
114 lines
4.5 KiB
Rust
|
use proc_macro::TokenStream;
|
||
|
|
use quote::quote;
|
||
|
|
use syn::{parse_macro_input, Data, DeriveInput, Fields};
|
||
|
|
|
||
|
|
/// Derives a `.send()` method for API query structs and enums using `awc::Client`.
|
||
|
|
///
|
||
|
|
/// - Structs: sends GET requests using fields prefixed with `lnk_p_` as query parameters.
|
||
|
|
/// - Enums: delegates `.send()` to inner struct that implements `Queryable`.
|
||
|
|
#[proc_macro_derive(HttpGetRequest)]
|
||
|
|
pub fn derive_http_get_request(input: TokenStream) -> TokenStream {
|
||
|
|
let input = parse_macro_input!(input as DeriveInput);
|
||
|
|
let name = input.ident;
|
||
|
|
|
||
|
|
let expanded = match &input.data {
|
||
|
|
// ---- Struct: Build .send() that builds and sends the GET request
|
||
|
|
Data::Struct(data_struct) => {
|
||
|
|
let fields = match &data_struct.fields {
|
||
|
|
Fields::Named(named) => &named.named,
|
||
|
|
_ => panic!("#[derive(HttpGetRequest)] supports only named fields for structs"),
|
||
|
|
};
|
||
|
|
|
||
|
|
// Gather query parameters from fields prefixed with lnk_p_
|
||
|
|
let mut query_param_code = Vec::new();
|
||
|
|
for field in fields {
|
||
|
|
let ident = field.ident.clone().unwrap();
|
||
|
|
let field_name = ident.to_string();
|
||
|
|
if field_name.starts_with("lnk_p_") {
|
||
|
|
let key = &field_name["lnk_p_".len()..];
|
||
|
|
query_param_code.push(quote! {
|
||
|
|
query_params.push((#key.to_string(), self.#ident.to_string()));
|
||
|
|
});
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
quote! {
|
||
|
|
impl #name {
|
||
|
|
/// Sends a GET request using `awc::Client`.
|
||
|
|
pub async fn send(
|
||
|
|
&self,
|
||
|
|
base_url: &str,
|
||
|
|
headers: Option<Vec<(&str, &str)>>
|
||
|
|
) -> Result<awc::ClientResponse, awc::error::SendRequestError> {
|
||
|
|
use awc::Client;
|
||
|
|
use urlencoding::encode;
|
||
|
|
|
||
|
|
// Collect query parameters
|
||
|
|
let mut query_params: Vec<(String, String)> = Vec::new();
|
||
|
|
#(#query_param_code)*
|
||
|
|
|
||
|
|
// Build URL with query string
|
||
|
|
let mut url = base_url.to_string();
|
||
|
|
if !query_params.is_empty() {
|
||
|
|
let mut query_parts = Vec::new();
|
||
|
|
for (k, v) in &query_params {
|
||
|
|
query_parts.push(format!("{}={}", k, encode(v)));
|
||
|
|
}
|
||
|
|
url.push('?');
|
||
|
|
url.push_str(&query_parts.join("&"));
|
||
|
|
}
|
||
|
|
|
||
|
|
// Prepare client and request
|
||
|
|
let client = Client::default();
|
||
|
|
let mut request = client.get(url);
|
||
|
|
|
||
|
|
// Optional headers
|
||
|
|
if let Some(hdrs) = headers {
|
||
|
|
for (k, v) in hdrs {
|
||
|
|
request = request.append_header((k, v));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Send the request
|
||
|
|
let response = request.send().await?;
|
||
|
|
Ok(response)
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// ---- Enum: Match each variant and call .send() on the inner type
|
||
|
|
Data::Enum(data_enum) => {
|
||
|
|
let mut variant_arms = Vec::new();
|
||
|
|
for variant in &data_enum.variants {
|
||
|
|
let vname = &variant.ident;
|
||
|
|
match &variant.fields {
|
||
|
|
Fields::Unnamed(fields) if fields.unnamed.len() == 1 => {
|
||
|
|
variant_arms.push(quote! {
|
||
|
|
#name::#vname(inner) => inner.send().await,
|
||
|
|
});
|
||
|
|
}
|
||
|
|
_ => panic!(
|
||
|
|
"#[derive(HttpGetRequest)] enum variants must have a single unnamed field"
|
||
|
|
),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
quote! {
|
||
|
|
impl #name {
|
||
|
|
/// Calls `.send()` on the wrapped query variant.
|
||
|
|
pub async fn send(&self) -> Result<awc::ClientResponse, awc::error::SendRequestError> {
|
||
|
|
match self {
|
||
|
|
#(#variant_arms)*
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
_ => panic!("#[derive(HttpGetRequest)] only supports structs and enums"),
|
||
|
|
};
|
||
|
|
|
||
|
|
TokenStream::from(expanded)
|
||
|
|
}
|