Implement Encodable and Decodable for Token

src/token.rs

@@ -1,4 +1,5 @@
-use chrono::{DateTime, UTC};
+use chrono::{DateTime, UTC, TimeZone};
+use rustc_serialize::{Encodable, Encoder, Decodable, Decoder};
 
 /// OAuth 2.0 access token.
 ///
@@ -29,3 +30,46 @@ impl Token {
         self.expires.map_or(false, |dt| dt < UTC::now())
     }
 }
+
+#[derive(RustcEncodable, RustcDecodable)]
+struct SerializableToken {
+    access_token: String,
+    token_type: String,
+    expires: Option<i64>,
+    refresh_token: Option<String>,
+    scope: Option<String>,
+}
+
+impl SerializableToken {
+    fn from_token(token: &Token) -> Self {
+        SerializableToken {
+            access_token: token.access_token.clone(),
+            token_type: token.token_type.clone(),
+            expires: token.expires.as_ref().map(DateTime::timestamp),
+            refresh_token: token.refresh_token.clone(),
+            scope: token.scope.clone(),
+        }
+    }
+
+    fn into_token(self) -> Token {
+        Token {
+            access_token: self.access_token,
+            token_type: self.token_type,
+            expires: self.expires.map(|t| UTC.timestamp(t, 0)),
+            refresh_token: self.refresh_token,
+            scope: self.scope,
+        }
+    }
+}
+
+impl Encodable for Token {
+    fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
+        SerializableToken::from_token(self).encode(s)
+    }
+}
+
+impl Decodable for Token {
+    fn decode<D: Decoder>(d: &mut D) -> Result<Self, D::Error> {
+        SerializableToken::decode(d).map(SerializableToken::into_token)
+    }
+}