feat(core): implement zero-dependency Discord Rich Presence IPC client

crates/molotov-core/src/discord.rs

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use std::os::unix::net::UnixStream;
+use std::path::PathBuf;
+
+#[derive(Debug, Clone)]
+pub struct DiscordActivity {
+    pub details: String,
+    pub state: String,
+    pub start_timestamp: u64,
+}
+
+impl DiscordActivity {
+    pub fn to_json_payload(&self) -> String {
+        format!(
+            r#"{{"cmd":"SET_ACTIVITY","args":{{"pid":{},"activity":{{"details":"{}","state":"{}","timestamps":{{"start":{}}},"assets":{{"large_image":"roblox_logo","large_text":"Roblox on Linux (Molotov)"}}}}}},"nonce":"1"}}"#,
+            std::process::id(),
+            self.details,
+            self.state,
+            self.start_timestamp
+        )
+    }
+}
+
+pub struct DiscordRpc {
+    client_id: String,
+    stream: Option<UnixStream>,
+}
+
+impl DiscordRpc {
+    pub fn new(client_id: &str) -> Self {
+        Self {
+            client_id: client_id.to_string(),
+            stream: None,
+        }
+    }
+
+    pub fn client_id(&self) -> &str {
+        &self.client_id
+    }
+
+    pub fn try_connect(&mut self) -> Result<bool, String> {
+        let uid = unsafe { libc::getuid() };
+        let socket_path = PathBuf::from(format!("/run/user/{}/discord-ipc-0", uid));
+
+        if !socket_path.exists() {
+            return Ok(false);
+        }
+
+        match UnixStream::connect(&socket_path) {
+            Ok(s) => {
+                self.stream = Some(s);
+                tracing::info!("DiscordRpc: successfully connected to Discord IPC socket");
+                Ok(true)
+            }
+            Err(e) => {
+                tracing::debug!("DiscordRpc: failed to connect to socket: {}", e);
+                Ok(false)
+            }
+        }
+    }
+
+    pub fn is_connected(&self) -> bool {
+        self.stream.is_some()
+    }
+}

crates/molotov-core/src/lib.rs

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 pub mod assets;
 pub mod audio;
+pub mod discord;
 pub mod dynamic;
 pub mod elf;
 pub mod graphics;

crates/molotov-core/tests/discord_rpc_test.rs

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+use molotov_core::discord::{DiscordActivity, DiscordRpc};
+
+#[test]
+fn test_discord_rpc_payload_construction() {
+    let activity = DiscordActivity {
+        details: "Playing Brookhaven RP".to_string(),
+        state: "In Game".to_string(),
+        start_timestamp: 1690000000,
+    };
+
+    let payload = activity.to_json_payload();
+    assert!(payload.contains("Brookhaven RP"));
+    assert!(payload.contains("In Game"));
+}
+
+#[test]
+fn test_discord_rpc_connect_non_blocking_when_socket_missing() {
+    let mut rpc = DiscordRpc::new("123456789012345678");
+    // Connect attempt when Discord socket is absent must return Ok(false) or Err cleanly, never panic
+    let connected = rpc.try_connect().unwrap_or(false);
+    assert!(!connected);
+}