taler-rust

GNU Taler code in Rust. Largely core banking integrations.
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api.rs (4958B)


      1 /*
      2   This file is part of TALER
      3   Copyright (C) 2025, 2026 Taler Systems SA
      4 
      5   TALER is free software; you can redistribute it and/or modify it under the
      6   terms of the GNU Affero General Public License as published by the Free Software
      7   Foundation; either version 3, or (at your option) any later version.
      8 
      9   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
     10   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
     11   A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details.
     12 
     13   You should have received a copy of the GNU Affero General Public License along with
     14   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
     15 */
     16 
     17 use std::borrow::Cow;
     18 
     19 use http_client::{
     20     ApiErr, Client, ClientErr, Ctx,
     21     builder::{Req, Res},
     22     headers::HeaderParser as _,
     23 };
     24 use hyper::{Method, StatusCode, header};
     25 use serde::{Deserialize, Serialize, de::DeserializeOwned};
     26 use thiserror::Error;
     27 use tracing::Level;
     28 use url::Url;
     29 
     30 use crate::magnet_api::oauth::{Token, oauth};
     31 
     32 #[derive(Deserialize, Debug)]
     33 struct Header {
     34     #[serde(rename = "errorCode")]
     35     pub error_code: Option<u16>,
     36 }
     37 
     38 #[derive(Deserialize, Debug)]
     39 struct Empty {}
     40 
     41 #[derive(Deserialize, Error, Debug)]
     42 #[error("{error_code} {short_message} '{long_message}'")]
     43 pub struct MagnetError {
     44     #[serde(rename = "errorCode")]
     45     pub error_code: u16,
     46     #[serde(rename = "shortMessage")]
     47     pub short_message: String,
     48     #[serde(rename = "longMessage")]
     49     pub long_message: String,
     50 }
     51 
     52 #[derive(Error, Debug)]
     53 pub enum MagnetErr {
     54     #[error("magnet {0}")]
     55     Magnet(#[from] MagnetError),
     56     #[error("status {0}")]
     57     Status(StatusCode),
     58     #[error("status {0} '{1}'")]
     59     StatusCause(StatusCode, String),
     60     #[error(transparent)]
     61     Client(#[from] ClientErr),
     62 }
     63 pub type ApiResult<R> = std::result::Result<R, ApiErr<MagnetErr>>;
     64 
     65 /** Handle error from magnet API calls */
     66 async fn error_handling(res: Res) -> Result<Res, MagnetErr> {
     67     let status = res.status();
     68     match status {
     69         StatusCode::OK => Ok(res),
     70         StatusCode::BAD_REQUEST => Err(MagnetErr::Status(status)),
     71         StatusCode::FORBIDDEN => {
     72             let cause = res.str_header(header::WWW_AUTHENTICATE)?;
     73             Err(MagnetErr::StatusCause(status, cause))
     74         }
     75         _ => {
     76             if tracing::enabled!(Level::DEBUG) {
     77                 let body = res.text().await;
     78                 tracing::debug!("unexpected error body: {:?}", body);
     79             }
     80             Err(MagnetErr::Status(status))
     81         }
     82     }
     83 }
     84 
     85 /** Parse JSON and track error path */
     86 fn parse<'de, T: Deserialize<'de>>(str: &'de str) -> Result<T, MagnetErr> {
     87     let deserializer = &mut serde_json::Deserializer::from_str(str);
     88     serde_path_to_error::deserialize(deserializer)
     89         .map_err(|e| MagnetErr::Client(ClientErr::ResJson(e)))
     90 }
     91 
     92 pub struct MagnetRequest<'a> {
     93     req: Req,
     94     consumer: &'a Token,
     95     access: Option<&'a Token>,
     96     verifier: Option<&'a str>,
     97 }
     98 
     99 impl<'a> MagnetRequest<'a> {
    100     pub fn new(
    101         client: &Client,
    102         method: Method,
    103         base_url: &Url,
    104         path: impl Into<Cow<'static, str>>,
    105         consumer: &'a Token,
    106         access: Option<&'a Token>,
    107         verifier: Option<&'a str>,
    108     ) -> Self {
    109         Self {
    110             req: Req::new(client, method, base_url, path),
    111             consumer,
    112             access,
    113             verifier,
    114         }
    115     }
    116 
    117     pub fn query<T: Serialize>(mut self, name: &str, value: T) -> Self {
    118         self.req = self.req.query(name, value);
    119         self
    120     }
    121 
    122     pub fn json<T: Serialize + ?Sized>(mut self, json: &T) -> Self {
    123         self.req = self.req.json(json);
    124         self
    125     }
    126 
    127     async fn send(self) -> ApiResult<(Ctx, Res)> {
    128         let Self {
    129             req,
    130             consumer,
    131             access,
    132             verifier,
    133         } = self;
    134         oauth(req, consumer, access, verifier)
    135             .send()
    136             .await
    137             .map_err(|(ctx, e)| ctx.wrap(e.into()))
    138     }
    139 
    140     pub async fn parse_url<T: DeserializeOwned>(self) -> ApiResult<T> {
    141         let (ctx, res) = self.send().await?;
    142         async { Ok(error_handling(res).await?.urlencoded().await?) }
    143             .await
    144             .map_err(|e| ctx.wrap(e))
    145     }
    146 
    147     pub async fn parse_json<T: DeserializeOwned>(self) -> ApiResult<T> {
    148         let (ctx, res) = self.send().await?;
    149         async {
    150             let res = error_handling(res).await?;
    151             let raw: Box<serde_json::value::RawValue> = res.json().await?;
    152             let header: Header = parse(raw.get())?;
    153             if header.error_code.unwrap_or(200) == 200 {
    154                 Ok(parse(raw.get())?)
    155             } else {
    156                 Err(MagnetErr::Magnet(parse(raw.get())?))
    157             }
    158         }
    159         .await
    160         .map_err(|e| ctx.wrap(e))
    161     }
    162 
    163     pub async fn parse_empty(self) -> ApiResult<()> {
    164         self.parse_json::<Empty>().await?;
    165         Ok(())
    166     }
    167 }