Implement some more commands

src/commands/queue/add.rs

@@ -0,0 +1,40 @@
+use crate::{
+    commands::{
+        Command, Request, RequestParserError, RequestParserResult, ResponseAttributes,
+        ResponseParserError,
+    },
+    common::SongPosition,
+};
+
+pub struct Add;
+
+impl Command for Add {
+    type Response = ();
+    const COMMAND: &'static str = "add";
+
+    fn parse_request(mut parts: std::str::SplitWhitespace<'_>) -> RequestParserResult<'_> {
+        let uri = match parts.next() {
+            Some(s) => s,
+            None => return Err(RequestParserError::UnexpectedEOF),
+        };
+
+        let position = match parts.next() {
+            Some(s) => Some(
+                s.parse::<SongPosition>()
+                    .map_err(|_| RequestParserError::SyntaxError(1, s.to_owned()))?,
+            ),
+            None => None,
+        };
+
+        debug_assert!(parts.next().is_none());
+
+        Ok((Request::Add(uri.to_string(), position), ""))
+    }
+
+    fn parse_response(
+        parts: ResponseAttributes<'_>,
+    ) -> Result<Self::Response, ResponseParserError> {
+        debug_assert!(parts.is_empty());
+        Ok(())
+    }
+}