From 91dd81690d62dfb599a553c12aa830c0706273f6 Mon Sep 17 00:00:00 2001
From: Curtis McEnroe <programble@gmail.com>
Date: Sat, 28 Nov 2015 18:07:01 -0500
Subject: [PATCH] Handle errors

---
 src/client.rs | 42 +++++++++++++++++++++++++++++++++++-------
 src/error.rs  |  5 +----
 2 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/src/client.rs b/src/client.rs
index b24b74a..0c18909 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -5,7 +5,8 @@ use hyper::{self, header, mime};
 use rustc_serialize::json;
 use url::{Url, form_urlencoded};
 
-use super::{Error, Result, Token};
+use super::Token;
+use super::error::{Error, Result, OAuth2Error, OAuth2ErrorCode};
 
 /// OAuth 2.0 client.
 pub struct Client {
@@ -40,6 +41,32 @@ impl Into<Token> for TokenResponse {
     }
 }
 
+#[derive(RustcDecodable)]
+struct ErrorResponse {
+    error: String,
+    error_description: Option<String>,
+    error_uri: Option<String>,
+}
+
+impl Into<OAuth2Error> for ErrorResponse {
+    fn into(self) -> OAuth2Error {
+        let code = match &self.error[..] {
+            "invalid_request" => OAuth2ErrorCode::InvalidRequest,
+            "invalid_client" => OAuth2ErrorCode::InvalidClient,
+            "invalid_grant" => OAuth2ErrorCode::InvalidGrant,
+            "unauthorized_client" => OAuth2ErrorCode::UnauthorizedClient,
+            "unsupported_grant_type" => OAuth2ErrorCode::UnsupportedGrantType,
+            "invalid_scope" => OAuth2ErrorCode::InvalidScope,
+            _ => OAuth2ErrorCode::Unrecognized(self.error),
+        };
+        OAuth2Error {
+            code: code,
+            description: self.error_description,
+            uri: self.error_uri,
+        }
+    }
+}
+
 macro_rules! site_constructors {
     (
         $(
@@ -161,14 +188,15 @@ impl Client {
             .body(&body_str);
 
         let mut response = try!(request.send());
-        let mut json = String::new();
-        try!(response.read_to_string(&mut json));
+        let mut body = String::new();
+        try!(response.read_to_string(&mut body));
 
-        if response.status != hyper::Ok {
-            return Err(Error::Todo);
+        let token = json::decode::<TokenResponse>(&body);
+        if let Ok(token) = token {
+            return Ok(token.into());
         }
 
-        let token: TokenResponse = try!(json::decode(&json));
-        Ok(token.into())
+        let error: ErrorResponse = try!(json::decode(&body));
+        Err(Error::OAuth2(error.into()))
     }
 }
diff --git a/src/error.rs b/src/error.rs
index 979cc45..47f86bc 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -13,6 +13,7 @@ pub enum OAuth2ErrorCode {
     UnauthorizedClient,
     UnsupportedGrantType,
     InvalidScope,
+    Unrecognized(String),
 }
 
 /// OAuth 2.0 error.
@@ -52,7 +53,6 @@ pub enum Error {
     Hyper(hyper::Error),
     Json(json::DecoderError),
     OAuth2(OAuth2Error),
-    Todo,
 }
 
 /// Result type returned from authentication flow methods.
@@ -66,7 +66,6 @@ impl fmt::Display for Error {
             Error::Hyper(ref err) => write!(f, "{}", err),
             Error::Json(ref err) => write!(f, "{}", err),
             Error::OAuth2(ref err) => write!(f, "{}", err),
-            Error::Todo => write!(f, "Not implemented!"),
         }
     }
 }
@@ -79,7 +78,6 @@ impl error::Error for Error {
             Error::Hyper(_) => "OAuth2 Hyper error",
             Error::Json(_) => "OAuth2 JSON error",
             Error::OAuth2(_) => "OAuth2 API error",
-            Error::Todo => "OAuth2 not implemented error",
         }
     }
 
@@ -90,7 +88,6 @@ impl error::Error for Error {
             Error::Hyper(ref err) => Some(err),
             Error::Json(ref err) => Some(err),
             Error::OAuth2(ref err) => Some(err),
-            _ => None,
         }
     }
 }