From aee39fc906b8333099f0b17d85d98d0e76965a1b Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Sun, 4 Aug 2024 16:15:11 +0200
Subject: [PATCH] WIP: centralize mpv broker

---
 src/mpv_broker.rs | 154 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 src/mpv_broker.rs

diff --git a/src/mpv_broker.rs b/src/mpv_broker.rs
new file mode 100644
index 0000000..dc83c33
--- /dev/null
+++ b/src/mpv_broker.rs
@@ -0,0 +1,154 @@
+use std::{fs::create_dir_all, path::Path};
+
+use anyhow::Context;
+use mpvipc_async::{Mpv, MpvCommand, Event as MpvEvent};
+use tokio::{process::{Child, Command}, sync::{broadcast::{Receiver as BroadcastReceiver, Sender as BroadcastSender}, mpsc::{Receiver as MpscReceiver, Sender as MpscSender}}};
+
+#[derive(Debug)]
+pub struct MpvBroker {
+    mpv: Mpv,
+    command_channel: MpscReceiver<MpvCommand>,
+    event_listeners: BroadcastSender<MpvEvent>,
+}
+
+impl MpvBroker {
+    pub fn new(
+        mpv: Mpv,
+        command_channel: MpscReceiver<MpvCommand>,
+        event_listeners: BroadcastSender<MpvEvent>,
+    ) -> Self {
+        Self {
+            mpv,
+            command_channel,
+            event_listeners,
+        }
+    }
+
+    pub async fn run(&mut self) -> anyhow::Result<()> {
+        loop {
+            tokio::select! {
+                Some(command) = self.command_channel.recv() => {
+                    self.mpv.run_command(command)?;
+                }
+                Ok(event) = async { self.mpv.event_listen() } => {
+                    self.event_listeners.send(event)?;
+                }
+            }
+        }
+    }
+}
+
+pub struct MpvConnectionArgs {
+    pub socket_path: String,
+    pub executable_path: Option<String>,
+    pub auto_start: bool,
+    pub force_auto_start: bool,
+}
+
+pub async fn connect_to_mpv(args: &MpvConnectionArgs) -> anyhow::Result<(Mpv, Option<Child>)> {
+    log::debug!("Connecting to mpv");
+
+    debug_assert!(
+        !args.force_auto_start || args.auto_start,
+        "force_auto_start requires auto_start"
+    );
+
+    let socket_path = Path::new(&args.socket_path);
+
+    if !socket_path.exists() {
+        log::debug!("Mpv socket not found at {}", &args.socket_path);
+        if !args.auto_start {
+            panic!("Mpv socket not found at {}", &args.socket_path);
+        }
+
+        log::debug!("Ensuring parent dir of mpv socket exists");
+        let parent_dir = Path::new(&args.socket_path)
+            .parent()
+            .context("Failed to get parent dir of mpv socket")?;
+
+        if !parent_dir.is_dir() {
+            create_dir_all(parent_dir).context("Failed to create parent dir of mpv socket")?;
+        }
+    } else {
+        log::debug!("Existing mpv socket found at {}", &args.socket_path);
+        if args.force_auto_start {
+            log::debug!("Removing mpv socket");
+            std::fs::remove_file(&args.socket_path)?;
+        }
+    }
+
+    let process_handle = if args.auto_start {
+        log::info!("Starting mpv with socket at {}", &args.socket_path);
+
+        // TODO: try to fetch mpv from PATH
+        Some(
+            Command::new(args.executable_path.as_deref().unwrap_or("mpv"))
+                .arg(format!("--input-ipc-server={}", &args.socket_path))
+                .arg("--idle")
+                .arg("--force-window")
+                // .arg("--fullscreen")
+                // .arg("--no-terminal")
+                // .arg("--load-unsafe-playlists")
+                .arg("--keep-open") // Keep last frame of video on end of video
+                .arg("--really-quiet")
+                .spawn()
+                .context("Failed to start mpv")?,
+        )
+    } else {
+        None
+    };
+
+    // Wait for mpv to create the socket
+    if tokio::time::timeout(tokio::time::Duration::from_millis(500), async {
+        while !&socket_path.exists() {
+            log::debug!("Waiting for mpv socket at {}", &args.socket_path);
+            tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .is_err()
+    {
+        return Err(anyhow::anyhow!(
+            "Failed to connect to mpv socket: {}",
+            &args.socket_path
+        ));
+    }
+
+    Ok((
+        Mpv::connect(&args.socket_path).context(format!(
+            "Failed to connect to mpv socket: {}",
+            &args.socket_path
+        ))?,
+        process_handle,
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use mpvipc_async::MpvCommand;
+    use tokio::sync::{broadcast, mpsc};
+
+    #[tokio::test]
+    async fn test_run() -> anyhow::Result<()> {
+        let (command_tx, command_rx) = mpsc::channel(1);
+        let (event_tx, _) = broadcast::channel(1);
+
+        let (mpv, _) = connect_to_mpv(&MpvConnectionArgs {
+            socket_path: "/tmp/mpv-test.sock".to_string(),
+            executable_path: None,
+            auto_start: true,
+            force_auto_start: true,
+        }).await?;
+
+        let mut broker = MpvBroker::new(mpv, command_rx, event_tx);
+        let broker_handle = tokio::spawn(async move {
+          broker.run().await.unwrap();
+        });
+
+        let _ = command_tx.send(MpvCommand::PlaylistClear).await;
+        let _ = broker_handle.await.unwrap();
+
+        Ok(())
+    }
+}
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