Replace common functionality with rust implementation

mgr/src/brightness.rs

@@ -0,0 +1,77 @@
+use thiserror::Error;
+
+use super::{
+    Exec,
+    cli::{self, CliCommand},
+    cmd,
+    wire::{WireCommand, server},
+};
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error(transparent)]
+    Cli(#[from] cli::ParseError),
+    #[error(transparent)]
+    Cmd(#[from] cmd::Error),
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Action {
+    Inc,
+    Dec,
+}
+
+impl WireCommand for Action {
+    fn parse_wire(mut input: impl Iterator<Item = u8>) -> Result<Self, server::ParseError> {
+        match input.next().ok_or(server::ParseError::Eof)? {
+            0x01 => Ok(Self::Inc),
+            0x02 => Ok(Self::Dec),
+            byte => Err(server::ParseError::Unknown(byte)),
+        }
+    }
+
+    fn to_wire(&self) -> Vec<u8> {
+        match *self {
+            Self::Inc => vec![0x01],
+            Self::Dec => vec![0x02],
+        }
+    }
+}
+
+impl CliCommand for Action {
+    type ExecErr = Error;
+
+    fn parse_str(input: &str, rest: impl Iterator<Item = String>) -> Result<Self, cli::ParseError>
+    where
+        Self: Sized,
+    {
+        let result = match input {
+            "inc" => Self::Inc,
+            "dec" => Self::Dec,
+            s => {
+                return Err(cli::ParseError::UnknownAction {
+                    action: s.to_owned(),
+                });
+            }
+        };
+
+        let rest = rest.collect::<Vec<String>>();
+        if rest.is_empty() {
+            Ok(result)
+        } else {
+            Err(cli::ParseError::UnexpectedInput { rest })
+        }
+    }
+}
+
+impl Exec for Action {
+    type ExecErr = Error;
+
+    fn execute(&self) -> Result<Option<String>, Self::ExecErr> {
+        match *self {
+            Self::Inc => cmd::command("brightnessctl", &["set", "8%+"])?,
+            Self::Dec => cmd::command("brightnessctl", &["set", "8%-"])?,
+        }
+        Ok(None)
+    }
+}