first commit

src/sieve/error.rs

@@ -0,0 +1,37 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub enum SieveError {
+    ConnectionFailed(String),
+    TlsFailed(String),
+    AuthenticationFailed(String),
+    InsecureAuthenticationBlocked,
+    Protocol(String),
+    ServerRejected(String),
+    Timeout,
+    ScriptTooLarge,
+}
+
+impl fmt::Display for SieveError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::ConnectionFailed(msg) => write!(f, "ManageSieve connection failed: {msg}"),
+            Self::TlsFailed(msg) => write!(f, "ManageSieve TLS failed: {msg}"),
+            Self::AuthenticationFailed(msg) => {
+                write!(f, "ManageSieve authentication failed: {msg}")
+            }
+            Self::InsecureAuthenticationBlocked => write!(
+                f,
+                "ManageSieve plaintext authentication is blocked; use STARTTLS/implicit TLS or explicitly enable SIEVE_ALLOW_INSECURE_AUTH"
+            ),
+            Self::Protocol(msg) => write!(f, "ManageSieve protocol error: {msg}"),
+            Self::ServerRejected(msg) => {
+                write!(f, "ManageSieve server rejected the command: {msg}")
+            }
+            Self::Timeout => write!(f, "ManageSieve operation timed out"),
+            Self::ScriptTooLarge => write!(f, "Sieve script exceeds the RustBox 0.0.1 size limit"),
+        }
+    }
+}
+
+impl std::error::Error for SieveError {}