implement default Bot's {Json,Multipart}Request

Cargo.toml

@@ -19,6 +19,7 @@ authors = [
 futures = "0.3.5"
 tokio = { version = "0.2.21", features = ["fs", "stream"] }
 tokio-util = "0.3.1"
+pin-project = "0.4.23"
 bytes = "0.5.5"
 async-trait = "0.1.36"
 reqwest = { version = "0.10.6", features = ["json", "stream"] }

src/bot/mod.rs

@@ -1,9 +1,17 @@
-use crate::types::ParseMode;
+use std::{future::Future, sync::Arc, time::Duration};
+
 use reqwest::{
     header::{HeaderMap, CONNECTION},
     Client, ClientBuilder,
 };
-use std::{sync::Arc, time::Duration};
+use serde::{de::DeserializeOwned, Serialize};
+
+use crate::{
+    net,
+    requests::{Payload, ResponseResult},
+    serde_multipart,
+    types::ParseMode,
+};
 
 mod api;
 mod download;
@@ -100,6 +108,47 @@ impl Bot {
     }
 }
 
+impl Bot {
+    pub(crate) fn execute_json<P>(
+        &self,
+        payload: &P,
+    ) -> impl Future<Output = ResponseResult<P::Output>> + 'static
+    where
+        P: Payload + Serialize,
+        P::Output: DeserializeOwned,
+    {
+        let client = self.client.clone();
+        let token = Arc::clone(&self.token);
+
+        let params = serde_json::to_vec(payload)
+            // this `expect` should be ok since we don't write request those may trigger error here
+            .expect("serialization of request to be infallible");
+
+        // async move to capture client&token
+        async move { net::request_json2(&client, token.as_ref(), P::NAME, params).await }
+    }
+
+    pub(crate) fn execute_multipart<P>(
+        &self,
+        payload: &P,
+    ) -> impl Future<Output = ResponseResult<P::Output>>
+    where
+        P: Payload + Serialize,
+        P::Output: DeserializeOwned,
+    {
+        let client = self.client.clone();
+        let token = Arc::clone(&self.token);
+
+        let params = serde_multipart::to_form(payload);
+
+        // async move to capture client&token&params
+        async move {
+            let params = params.await?;
+            net::request_multipart2(&client, token.as_ref(), P::NAME, params).await
+        }
+    }
+}
+
 /// Returns a builder with safe settings.
 ///
 /// By "safe settings" I mean that a client will be able to work in long time

src/local_macros.rs

@@ -36,3 +36,73 @@ macro_rules! forward_to_unsuported_ty {
         )+
     };
 }
+
+#[macro_use]
+macro_rules! req_future {
+    (
+        $v2:vis def: | $( $arg:ident: $ArgTy:ty ),* $(,)? | $body:block
+
+        $(#[$($meta:tt)*])*
+        $v:vis $i:ident<$T:ident> ($inner:ident) -> $Out:ty
+        $(where $($wh:tt)*)?
+    ) => {
+        #[pin_project::pin_project]
+        $v struct $i<$T>
+        $(where $($wh)*)?
+        {
+            #[pin]
+            inner: $inner::$i<$T>
+        }
+
+        impl<$T> $i<$T>
+        $(where $($wh)*)?
+        {
+            $v2 fn new($( $arg: $ArgTy ),*) -> Self {
+                Self { inner: $inner::def($( $arg ),*) }
+            }
+        }
+
+        // HACK(waffle): workaround for https://github.com/rust-lang/rust/issues/55997
+        mod $inner {
+            #![allow(type_alias_bounds)]
+
+            // Mostly to bring `use`s
+            #[allow(unused_imports)]
+            use super::{*, $i as _};
+
+            #[cfg(feature = "nightly")]
+            pub(crate) type $i<$T>
+            $(where $($wh)*)? = impl ::core::future::Future<Output = $Out>;
+
+            #[cfg(feature = "nightly")]
+            pub(crate) fn def<$T>($( $arg: $ArgTy ),*) -> $i<$T>
+            $(where $($wh)*)?
+            {
+                $body
+            }
+
+            #[cfg(not(feature = "nightly"))]
+            pub(crate) type $i<$T>
+            $(where $($wh)*)?  = ::core::pin::Pin<Box<dyn ::core::future::Future<Output = $Out>>>;
+
+            #[cfg(not(feature = "nightly"))]
+            pub(crate) fn def<$T>($( $arg: $ArgTy ),*) -> $i<$T>
+            $(where $($wh)*)?
+            {
+                Box::pin($body)
+            }
+        }
+
+        impl<$T> ::core::future::Future for $i<$T>
+        $(where $($wh)*)?
+        {
+            type Output = $Out;
+
+            fn poll(self: ::core::pin::Pin<&mut Self>, cx: &mut ::core::task::Context<'_>) -> ::core::task::Poll<Self::Output> {
+                let this = self.project();
+                this.inner.poll(cx)
+            }
+        }
+
+    };
+}

src/net/mod.rs

@@ -3,7 +3,7 @@ pub use download::download_file_stream;
 
 pub use self::{
     download::download_file,
-    request::{request_json, request_multipart},
+    request::{request_json, request_json2, request_multipart, request_multipart2},
     telegram_response::TelegramResponse,
 };
 

src/net/request.rs

@@ -1,6 +1,9 @@
 use std::time::Duration;
 
-use reqwest::{Client, Response};
+use reqwest::{
+    header::{HeaderValue, CONTENT_TYPE},
+    Client, Response,
+};
 use serde::{de::DeserializeOwned, Serialize};
 
 use crate::{
@@ -61,6 +64,50 @@ where
     process_response(response).await
 }
 
+// FIXME(waffle):
+//   request_{json,mutipart} are currently used in old code, so we keep them
+//   for now when they will not be used anymore, we should remove them
+//   and rename request_{json,mutipart}2 => request_{json,mutipart}
+
+pub async fn request_multipart2<T>(
+    client: &Client,
+    token: &str,
+    method_name: &str,
+    params: reqwest::multipart::Form,
+) -> ResponseResult<T>
+where
+    T: DeserializeOwned,
+{
+    let response = client
+        .post(&super::method_url(TELEGRAM_API_URL, token, method_name))
+        .multipart(params)
+        .send()
+        .await
+        .map_err(RequestError::NetworkError)?;
+
+    process_response(response).await
+}
+
+pub async fn request_json2<T>(
+    client: &Client,
+    token: &str,
+    method_name: &str,
+    params: Vec<u8>,
+) -> ResponseResult<T>
+where
+    T: DeserializeOwned,
+{
+    let response = client
+        .post(&super::method_url(TELEGRAM_API_URL, token, method_name))
+        .header(CONTENT_TYPE, HeaderValue::from_static("application/json"))
+        .body(params)
+        .send()
+        .await
+        .map_err(RequestError::NetworkError)?;
+
+    process_response(response).await
+}
+
 async fn process_response<T>(response: Response) -> ResponseResult<T>
 where
     T: DeserializeOwned,

src/requests/json.rs

@@ -0,0 +1,106 @@
+use serde::{de::DeserializeOwned, Serialize};
+
+use crate::{
+    bot::Bot,
+    requests::{HasPayload, Payload, Request, ResponseResult},
+    RequestError,
+};
+
+/// Ready-to-send telegram request.
+///
+/// Note: payload will be sent to telegram using [`json`]
+///
+/// [`json`]: https://core.telegram.org/bots/api#making-requests
+#[must_use = "requests do nothing until sent"]
+pub struct JsonRequest<P> {
+    bot: Bot,
+    payload: P,
+}
+
+impl<P> JsonRequest<P> {
+    pub const fn new(bot: Bot, payload: P) -> Self {
+        Self { bot, payload }
+    }
+}
+
+impl<P> Request for JsonRequest<P>
+where
+    // FIXME(waffle):
+    //   this is required on stable because of
+    //   https://github.com/rust-lang/rust/issues/76882
+    //   when it's resolved or `type_alias_impl_trait` feature
+    //   stabilized, we should remove 'static restriction
+    //
+    // (though critically, currently we have no
+    // non-'static payloads)
+    P: 'static,
+    P: Payload + Serialize,
+    P::Output: DeserializeOwned,
+{
+    type Err = RequestError;
+    type Send = Send<P>;
+    type SendRef = SendRef<P>;
+
+    fn send(self) -> Self::Send {
+        Send::new(self)
+    }
+
+    fn send_ref(&self) -> Self::SendRef {
+        SendRef::new(self)
+    }
+}
+
+impl<P> HasPayload for JsonRequest<P>
+where
+    P: Payload,
+{
+    type Payload = P;
+}
+
+impl<P> AsRef<P> for JsonRequest<P> {
+    fn as_ref(&self) -> &P {
+        &self.payload
+    }
+}
+
+impl<P> AsMut<P> for JsonRequest<P> {
+    fn as_mut(&mut self) -> &mut P {
+        &mut self.payload
+    }
+}
+
+impl<P: Payload + Serialize> core::ops::Deref for JsonRequest<P> {
+    type Target = P;
+
+    fn deref(&self) -> &Self::Target {
+        self.as_ref()
+    }
+}
+
+impl<P: Payload + Serialize> core::ops::DerefMut for JsonRequest<P> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.as_mut()
+    }
+}
+
+req_future! {
+    def: |it: JsonRequest<U>| {
+        it.bot.execute_json(&it.payload)
+    }
+    pub Send<U> (inner0) -> ResponseResult<U::Output>
+    where
+        U: 'static,
+        U: Payload + Serialize,
+        U::Output: DeserializeOwned,
+}
+
+req_future! {
+    def: |it: &JsonRequest<U>| {
+        it.bot.execute_json(&it.payload)
+    }
+    pub SendRef<U> (inner1) -> ResponseResult<U::Output>
+    where
+        U: 'static,
+        U: Payload + Serialize,
+        U::Output: DeserializeOwned,
+}

src/requests/mod.rs

@@ -7,9 +7,13 @@ mod request;
 pub use self::{has_payload::HasPayload, payload::Payload, request::Request};
 
 mod all;
+mod json;
+mod multipart;
 mod utils;
 
 pub use all::*;
+pub use json::JsonRequest;
+pub use multipart::MultipartRequest;
 
 /// A type that is returned after making a request to Telegram.
 pub type ResponseResult<T> = Result<T, crate::RequestError>;