Reenable send_reply

This reverts commit 36fb89b956
                and 76e8c0d8f2.

src/browser.rs

@@ -1,7 +1,7 @@
 use serde::Deserialize;
 use std::io;
 use std::io::BufReader;
-use std::io::Read;
+use std::io::{Read, Write};
 
 use crate::error::FF2MpvError;
 
@@ -10,6 +10,10 @@ pub struct FF2MpvMessage {
     pub url: String,
 }
 
+pub fn send_reply() -> Result<(), io::Error> {
+    send_message("ok")
+}
+
 pub fn get_mpv_message() -> Result<FF2MpvMessage, FF2MpvError> {
     let message = read_message()?;
     let ff2mpv_message = serde_json::from_str(&message)?;
@@ -28,3 +32,13 @@ fn read_message() -> Result<String, io::Error> {
     reader.read_to_string(&mut string)?;
     Ok(string)
 }
+
+fn send_message(message: &str) -> Result<(), io::Error> {
+    let length = (message.len() as u32).to_ne_bytes();
+    let message = message.as_bytes();
+
+    let mut stdout = io::stdout();
+    stdout.write_all(&length)?;
+    stdout.write_all(message)?;
+    Ok(())
+}