feat: add Windows IME IPC protocol

openless-all/app/src-tauri/src/lib.rs

@@ -20,6 +20,7 @@ mod persistence;
 mod polish;
 mod recorder;
 mod types;
+mod windows_ime_protocol;
 
 #[cfg(target_os = "macos")]
 use std::sync::mpsc;

openless-all/app/src-tauri/src/windows_ime_protocol.rs

@@ -0,0 +1,112 @@
+use serde::{Deserialize, Serialize};
+
+pub const OPENLESS_IME_PROTOCOL_VERSION: u32 = 1;
+pub const OPENLESS_IME_PIPE_NAME: &str = r"\\.\pipe\OpenLessImeSubmit";
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(
+    tag = "type",
+    rename_all = "camelCase",
+    rename_all_fields = "camelCase"
+)]
+pub enum ImePipeMessage {
+    ClientReady {
+        protocol_version: u32,
+        client_id: String,
+        process_id: u32,
+        thread_id: u32,
+    },
+    SubmitText {
+        protocol_version: u32,
+        session_id: String,
+        text: String,
+        created_at: String,
+    },
+    SubmitResult {
+        protocol_version: u32,
+        session_id: String,
+        status: ImeSubmitStatus,
+        error_code: Option<String>,
+    },
+    CancelSession {
+        protocol_version: u32,
+        session_id: String,
+    },
+    Ping {
+        protocol_version: u32,
+    },
+}
+
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(rename_all = "camelCase")]
+pub enum ImeSubmitStatus {
+    Committed,
+    Rejected,
+    Failed,
+}
+
+pub fn encode_message(message: &ImePipeMessage) -> Result<String, serde_json::Error> {
+    let mut line = serde_json::to_string(message)?;
+    line.push('\n');
+    Ok(line)
+}
+
+pub fn decode_message(line: &str) -> Result<ImePipeMessage, serde_json::Error> {
+    serde_json::from_str(line)
+}
+
+pub fn is_result_for_pending_session(
+    message: &ImePipeMessage,
+    pending_session_id: &str,
+) -> Result<(), &'static str> {
+    match message {
+        ImePipeMessage::SubmitResult { session_id, .. } if session_id == pending_session_id => {
+            Ok(())
+        }
+        ImePipeMessage::SubmitResult { .. } => Err("submit result belongs to a different session"),
+        _ => Err("message is not a submit result"),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn submit_text_roundtrips_as_camel_case_json() {
+        let message = ImePipeMessage::SubmitText {
+            protocol_version: OPENLESS_IME_PROTOCOL_VERSION,
+            session_id: "session-1".to_string(),
+            text: "\u{4f60}\u{597d} OpenLess".to_string(),
+            created_at: "2026-05-01T12:00:00Z".to_string(),
+        };
+
+        let json = encode_message(&message).expect("encode");
+        assert!(json.contains("\"submitText\""));
+        assert!(json.contains("\"sessionId\""));
+        assert!(json.contains("\"createdAt\""));
+        assert!(!json.contains("\"session_id\""));
+        assert!(!json.contains("\"created_at\""));
+        assert!(json.ends_with('\n'));
+
+        let decoded = decode_message(json.trim_end()).expect("decode");
+        assert_eq!(decoded, message);
+    }
+
+    #[test]
+    fn stale_submit_result_is_rejected() {
+        let result = ImePipeMessage::SubmitResult {
+            protocol_version: OPENLESS_IME_PROTOCOL_VERSION,
+            session_id: "old-session".to_string(),
+            status: ImeSubmitStatus::Committed,
+            error_code: Some("ime-busy".to_string()),
+        };
+
+        let json = encode_message(&result).expect("encode");
+        assert!(json.contains("\"errorCode\""));
+        assert!(!json.contains("\"error_code\""));
+
+        assert!(is_result_for_pending_session(&result, "current-session").is_err());
+        assert!(is_result_for_pending_session(&result, "old-session").is_ok());
+    }
+}