add Token struct and impl

src/instance.rs

@@ -1,9 +1,12 @@
+use regex::Regex;
+
 use crate::api::schemas::schemas::InstancePoliciesSchema;
 use crate::gateway::Gateway;
 use crate::limit::LimitedRequester;
 use crate::URLBundle;
 
 use std::collections::HashMap;
+use std::fmt;
 
 #[derive(Debug)]
 /**
@@ -15,8 +18,46 @@ pub struct Instance {
     instance_info: InstancePoliciesSchema,
     requester: LimitedRequester,
     gateway: Gateway,
+    users: HashMap<Token, String>,
 }
 
 impl Instance {
     pub fn new() {}
 }
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Token {
+    pub token: String,
+}
+
+impl Token {
+    pub fn new(token: String) -> Result<Token, TokenFormatError> {
+        let token_regex = Regex::new(r"/[\w-]{24}\.[\w-]{6}\.[\w-]{27}/").unwrap();
+        let mfa_token_regex = Regex::new(r"/mfa\.[\w-]{84}/").unwrap();
+        if !token_regex.is_match(&token.as_str()) && !mfa_token_regex.is_match(&token.as_str()) {
+            return Err(TokenFormatError {
+                message: "This does not seem to be a valid token.".to_string(),
+            });
+        }
+        Ok(Token { token })
+    }
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct TokenFormatError {
+    pub message: String,
+}
+
+impl TokenFormatError {
+    fn new(message: String) -> Self {
+        TokenFormatError { message }
+    }
+}
+
+impl fmt::Display for TokenFormatError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.message)
+    }
+}
+
+impl std::error::Error for TokenFormatError {}