Add fetch-channel command

src/cli.rs

@@ -31,7 +31,12 @@ pub struct ChannelsArgs {
 pub struct FetchArgs {
     #[arg(long)]
     strict_client: bool,
-    client: String,
+    #[arg(long)]
+    strict_channel: bool,
+    #[arg(long)]
+    channel: Option<String>,
+    #[arg(long)]
+    client: Option<String>,
 }
 
 #[derive(Args)]
@@ -58,12 +63,29 @@ pub struct UpdateArgs {
     speakers: Option<bool>,
 }
 
-
 impl FetchArgs {
-    pub fn client(&self, connection: &mut Telnet) -> Result<Option<ResponseClient>, String> {
-        utils::find_client(connection, &self.client, self.strict_client)
+    pub fn want_channel(&self) -> bool {
+        self.channel.is_some()
     }
 
+    pub fn want_client(&self) -> bool {
+        self.client.is_some()
+    }
+
+    pub fn channel(&self, connection: &mut Telnet) -> Result<Option<ResponseChannel>, String> {
+        if let Some(channel) = &self.channel {
+            utils::find_channel(connection, channel, self.strict_channel)
+        } else {
+            Err("No channel specified.".to_string())
+        }
+    }
+    pub fn client(&self, connection: &mut Telnet) -> Result<Option<ResponseClient>, String> {
+        if let Some(client) = &self.client {
+            utils::find_client(connection, client, self.strict_client)
+        } else {
+            Err("No client specified.".to_string())
+        }
+    }
 }
 
 impl MoveArgs {