Support remote libraries (#36)

Closes #5

Reviewed-on: https://git.wojciechkozlowski.eu/wojtek/musichoard/pulls/36

Cargo.lock

@@ -43,6 +43,12 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bytes"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89b2fd2a0dcf38d7971e2194b6b6eebab45ae01067456a7fd93d5547a61b70be"
+
 [[package]]
 name = "cassowary"
 version = "0.3.0"
@@ -107,6 +113,26 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6184e33543162437515c2e2b48714794e37845ec9851711914eec9d308f6ebe8"
 
+[[package]]
+name = "dirs"
+version = "4.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3aa72a6f96ea37bbc5aa912f6788242832f75369bdfdadcb0e38423f100059"
+dependencies = [
+ "dirs-sys",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b1d1d91c932ef41c0f2663aa8b0ca0342d444d842c06914aa0a7e352d0bada6"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
+]
+
 [[package]]
 name = "downcast"
 version = "0.11.0"
@@ -164,6 +190,17 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c2141d6d6c8512188a7891b4b01590a45f6dac67afb4f255c4124dbb86d4eaa"
 
+[[package]]
+name = "getrandom"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c85e1d9ab2eadba7e5040d4e09cbd6d072b76a557ad64e797c2cb9d4da21d7e4"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "heck"
 version = "0.3.3"
@@ -312,11 +349,13 @@ dependencies = [
  "crossterm",
  "mockall",
  "once_cell",
+ "openssh",
  "ratatui",
  "serde",
  "serde_json",
  "structopt",
  "tempfile",
+ "tokio",
  "uuid",
 ]
 
@@ -341,6 +380,39 @@ version = "1.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7e5500299e16ebb147ae15a00a942af264cf3688f47923b8fc2cd5858f23ad3"
 
+[[package]]
+name = "openssh"
+version = "0.9.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ca6c277973fb549b36dd8980941b5ea3ecebea026f5b1f0060acde74d893c22"
+dependencies = [
+ "dirs",
+ "libc",
+ "once_cell",
+ "openssh-mux-client",
+ "shell-escape",
+ "tempfile",
+ "thiserror",
+ "tokio",
+ "tokio-pipe",
+]
+
+[[package]]
+name = "openssh-mux-client"
+version = "0.15.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88eac793af6170bcd6d4f39c3b7ba3f4227cab5680d7189ba30f9d174600b75f"
+dependencies = [
+ "once_cell",
+ "sendfd",
+ "serde",
+ "ssh_format",
+ "thiserror",
+ "tokio",
+ "tokio-io-utility",
+ "typed-builder",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.1"
@@ -364,6 +436,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "pin-project-lite"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e0a7ae3ac2f1173085d398531c705756c94a4c56843785df85a60c1a0afac116"
+
 [[package]]
 name = "predicates"
 version = "2.1.5"
@@ -467,6 +545,17 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "redox_users"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b033d837a7cf162d7993aded9304e30a83213c648b6e389db233191f891e5c2b"
+dependencies = [
+ "getrandom",
+ "redox_syscall 0.2.16",
+ "thiserror",
+]
+
 [[package]]
 name = "regex"
 version = "1.7.3"
@@ -510,6 +599,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "sendfd"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "604b71b8fc267e13bb3023a2c901126c8f349393666a6d98ac1ae5729b701798"
+dependencies = [
+ "libc",
+ "tokio",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.159"
@@ -541,6 +640,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "shell-escape"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "45bb67a18fa91266cc7807181f62f9178a6873bfad7dc788c42e6430db40184f"
+
 [[package]]
 name = "signal-hook"
 version = "0.3.15"
@@ -577,6 +682,25 @@ version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a507befe795404456341dfab10cef66ead4c041f62b8b11bbb92bffe5d0953e0"
 
+[[package]]
+name = "socket2"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64a4a911eed85daf18834cfaa86a79b7d266ff93ff5ba14005426219480ed662"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "ssh_format"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8701239872766d43b8a5f9a560ff7f002b48064fadea87f44a70507069fb482"
+dependencies = [
+ "serde",
+]
+
 [[package]]
 name = "strsim"
 version = "0.8.0"
@@ -657,6 +781,84 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "978c9a314bd8dc99be594bc3c175faaa9794be04a5a5e153caba6915336cebac"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9456a42c5b0d803c8cd86e73dd7cc9edd429499f37a3550d286d5e86720569f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.11",
+]
+
+[[package]]
+name = "tokio"
+version = "1.27.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0de47a4eecbe11f498978a9b29d792f0d2692d1dd003650c24c76510e3bc001"
+dependencies = [
+ "autocfg",
+ "bytes",
+ "libc",
+ "mio",
+ "pin-project-lite",
+ "signal-hook-registry",
+ "socket2",
+ "tokio-macros",
+ "windows-sys",
+]
+
+[[package]]
+name = "tokio-io-utility"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d672654d175710e52c7c41f6aec77c62b3c0954e2a7ebce9049d1e94ed7c263"
+dependencies = [
+ "tokio",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61a573bdc87985e9d6ddeed1b3d864e8a302c847e40d647746df2f1de209d1ce"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.11",
+]
+
+[[package]]
+name = "tokio-pipe"
+version = "0.2.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f213a84bffbd61b8fa0ba8a044b4bbe35d471d0b518867181e82bd5c15542784"
+dependencies = [
+ "libc",
+ "tokio",
+]
+
+[[package]]
+name = "typed-builder"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89851716b67b937e393b3daa8423e67ddfc4bbbf1654bcf05488e95e0828db0c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.8"

Cargo.toml

@@ -7,10 +7,12 @@ edition = "2021"
 
 [dependencies]
 crossterm = "0.26.1"
+openssh = { version = "0.9.9", features = ["native-mux"], default-features = false }
 serde = { version = "1.0.159", features = ["derive"] }
 serde_json = "1.0.95"
 structopt = "0.3.26"
 ratatui = "0.20.1"
+tokio = { version = "1.27.0", features = ["rt"] }
 uuid = { version = "1.3.0", features = ["serde"] }
 
 [dev-dependencies]

src/database/json/backend.rs

@@ -0,0 +1,30 @@
+//! Module for storing MusicHoard data in a JSON file database.
+
+use std::fs;
+use std::path::PathBuf;
+
+use super::JsonDatabaseBackend;
+
+/// JSON database backend that uses a local file for persistent storage.
+pub struct JsonDatabaseFileBackend {
+    path: PathBuf,
+}
+
+impl JsonDatabaseFileBackend {
+    /// Create a [`JsonDatabaseFileBackend`] that will read/write to the provided path.
+    pub fn new<P: Into<PathBuf>>(path: P) -> Self {
+        JsonDatabaseFileBackend { path: path.into() }
+    }
+}
+
+impl JsonDatabaseBackend for JsonDatabaseFileBackend {
+    fn read(&self) -> Result<String, std::io::Error> {
+        // Read entire file to memory as for now this is faster than a buffered read from disk:
+        // https://github.com/serde-rs/json/issues/160
+        fs::read_to_string(&self.path)
+    }
+
+    fn write(&mut self, json: &str) -> Result<(), std::io::Error> {
+        fs::write(&self.path, json)
+    }
+}

src/database/json/mod.rs

@@ -1,8 +1,5 @@
 //! Module for storing MusicHoard data in a JSON file database.
 
-use std::fs;
-use std::path::PathBuf;
-
 use serde::de::DeserializeOwned;
 use serde::Serialize;
 
@@ -11,6 +8,8 @@ use mockall::automock;
 
 use super::{Database, Error};
 
+pub mod backend;
+
 impl From<serde_json::Error> for Error {
     fn from(err: serde_json::Error) -> Error {
         Error::SerDeError(err.to_string())
@@ -53,30 +52,6 @@ impl<JDB: JsonDatabaseBackend> Database for JsonDatabase<JDB> {
     }
 }
 
-/// JSON database backend that uses a local file for persistent storage.
-pub struct JsonDatabaseFileBackend {
-    path: PathBuf,
-}
-
-impl JsonDatabaseFileBackend {
-    /// Create a [`JsonDatabaseFileBackend`] that will read/write to the provided path.
-    pub fn new<P: Into<PathBuf>>(path: P) -> Self {
-        JsonDatabaseFileBackend { path: path.into() }
-    }
-}
-
-impl JsonDatabaseBackend for JsonDatabaseFileBackend {
-    fn read(&self) -> Result<String, std::io::Error> {
-        // Read entire file to memory as for now this is faster than a buffered read from disk:
-        // https://github.com/serde-rs/json/issues/160
-        fs::read_to_string(&self.path)
-    }
-
-    fn write(&mut self, json: &str) -> Result<(), std::io::Error> {
-        fs::write(&self.path, json)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use std::collections::HashMap;

src/library/beets/executor.rs

@@ -0,0 +1,140 @@
+//! Module for interacting with the music library via
+//! [beets](https://beets.readthedocs.io/en/stable/).
+
+use std::{
+    ffi::OsString,
+    path::PathBuf,
+    process::{Command, Output},
+    str,
+};
+
+use openssh::{KnownHosts, Session};
+use tokio::runtime::{self, Runtime};
+
+use super::{BeetsLibraryExecutor, Error};
+
+const BEET_DEFAULT: &str = "beet";
+
+trait BeetsLibraryExecutorPrivate {
+    fn output(output: Output) -> Result<Vec<String>, Error> {
+        if !output.status.success() {
+            return Err(Error::Executor(
+                String::from_utf8_lossy(&output.stderr).to_string(),
+            ));
+        }
+        let output = str::from_utf8(&output.stdout)?;
+        Ok(output.split('\n').map(|s| s.to_string()).collect())
+    }
+}
+
+/// Beets library executor that executes beets commands in their own process.
+pub struct BeetsLibraryProcessExecutor {
+    bin: OsString,
+    config: Option<PathBuf>,
+}
+
+impl BeetsLibraryProcessExecutor {
+    /// Create a new [`BeetsLibraryProcessExecutor`] that uses the default beets executable.
+    pub fn new() -> Self {
+        Self::bin(BEET_DEFAULT)
+    }
+
+    /// Create a new [`BeetsLibraryProcessExecutor`] that uses the provided beets executable.
+    pub fn bin<S: Into<OsString>>(bin: S) -> Self {
+        BeetsLibraryProcessExecutor {
+            bin: bin.into(),
+            config: None,
+        }
+    }
+
+    /// Update the configuration file passed to the beets executable.
+    pub fn config<P: Into<PathBuf>>(mut self, path: Option<P>) -> Self {
+        self.config = path.map(|p| p.into());
+        self
+    }
+}
+
+impl Default for BeetsLibraryProcessExecutor {
+    /// Create a new [`BeetsLibraryProcessExecutor`] that uses the system's default beets
+    /// executable.
+    fn default() -> Self {
+        BeetsLibraryProcessExecutor::new()
+    }
+}
+
+impl BeetsLibraryExecutor for BeetsLibraryProcessExecutor {
+    fn exec<S: AsRef<str> + 'static>(&mut self, arguments: &[S]) -> Result<Vec<String>, Error> {
+        let mut cmd = Command::new(&self.bin);
+        if let Some(ref path) = self.config {
+            cmd.arg("--config");
+            cmd.arg(path);
+        }
+        let output = cmd.args(arguments.iter().map(|s| s.as_ref())).output()?;
+        Self::output(output)
+    }
+}
+
+impl BeetsLibraryExecutorPrivate for BeetsLibraryProcessExecutor {}
+
+// GRCOV_EXCL_START
+/// Beets library executor that executes beets commands over SSH.
+pub struct BeetsLibrarySshExecutor {
+    rt: Runtime,
+    session: Session,
+    bin: String,
+    config: Option<String>,
+}
+
+impl From<openssh::Error> for Error {
+    fn from(err: openssh::Error) -> Error {
+        Error::Executor(err.to_string())
+    }
+}
+
+impl BeetsLibrarySshExecutor {
+    /// Create a new [`BeetsLibrarySshExecutor`] that uses the default beets executable over an SSH
+    /// connection. This call will attempt to establish the connection and will fail if the
+    /// connection fails.
+    pub fn new<H: AsRef<str>>(host: H) -> Result<Self, Error> {
+        Self::bin(host, BEET_DEFAULT)
+    }
+
+    /// Create a new [`BeetsLibrarySshExecutor`] that uses the provided beets executable over an SSH
+    /// connection. This call will attempt to establish the connection and will fail if the
+    /// connection fails.
+    pub fn bin<H: AsRef<str>, S: Into<String>>(host: H, bin: S) -> Result<Self, Error> {
+        let rt = runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap();
+        let session = rt.block_on(Session::connect_mux(host, KnownHosts::Strict))?;
+        Ok(BeetsLibrarySshExecutor {
+            rt,
+            session,
+            bin: bin.into(),
+            config: None,
+        })
+    }
+
+    /// Update the configuration file passed to the beets executable.
+    pub fn config<P: Into<String>>(mut self, path: Option<P>) -> Self {
+        self.config = path.map(|p| p.into());
+        self
+    }
+}
+
+impl BeetsLibraryExecutor for BeetsLibrarySshExecutor {
+    fn exec<S: AsRef<str> + 'static>(&mut self, arguments: &[S]) -> Result<Vec<String>, Error> {
+        let mut cmd = self.session.command(&self.bin);
+        if let Some(ref path) = self.config {
+            cmd.arg("--config");
+            cmd.arg(path);
+        }
+        cmd.args(arguments.iter().map(|s| s.as_ref()));
+        let output = self.rt.block_on(cmd.output())?;
+        Self::output(output)
+    }
+}
+
+impl BeetsLibraryExecutorPrivate for BeetsLibrarySshExecutor {}
+// GRCOV_EXCL_STOP

src/library/beets/mod.rs

@@ -3,9 +3,6 @@
 
 use std::{
     collections::{HashMap, HashSet},
-    ffi::OsString,
-    path::PathBuf,
-    process::Command,
     str,
 };
 
@@ -16,6 +13,8 @@ use crate::{Album, AlbumId, Artist, ArtistId, Track, TrackFormat};
 
 use super::{Error, Field, Library, Query};
 
+pub mod executor;
+
 macro_rules! list_format_separator {
     () => {
         " -*^- "
@@ -95,7 +94,7 @@ trait LibraryPrivate {
 }
 
 impl<BLE: BeetsLibraryExecutor> BeetsLibrary<BLE> {
-    /// Create a new beets library with the provided executor, e.g. [`BeetsLibraryCommandExecutor`].
+    /// Create a new beets library with the provided executor, e.g. [`BeetsLibraryProcessExecutor`].
     pub fn new(executor: BLE) -> Self {
         BeetsLibrary { executor }
     }
@@ -198,53 +197,6 @@ impl<BLE: BeetsLibraryExecutor> LibraryPrivate for BeetsLibrary<BLE> {
     }
 }
 
-/// Beets library executor that executes beets commands in their own process.
-pub struct BeetsLibraryCommandExecutor {
-    bin: OsString,
-    config: Option<PathBuf>,
-}
-
-impl BeetsLibraryCommandExecutor {
-    /// Create a new [`BeetsLibraryCommandExecutor`] that uses the provided beets executable.
-    pub fn new<S: Into<OsString>>(bin: S) -> Self {
-        BeetsLibraryCommandExecutor {
-            bin: bin.into(),
-            config: None,
-        }
-    }
-
-    /// Update the configuration file passed to the beets executable.
-    pub fn config<P: Into<PathBuf>>(mut self, path: Option<P>) -> Self {
-        self.config = path.map(|p| p.into());
-        self
-    }
-}
-
-impl Default for BeetsLibraryCommandExecutor {
-    /// Create a new [`BeetsLibraryCommandExecutor`] that uses the system's default beets executable.
-    fn default() -> Self {
-        BeetsLibraryCommandExecutor::new("beet")
-    }
-}
-
-impl BeetsLibraryExecutor for BeetsLibraryCommandExecutor {
-    fn exec<S: AsRef<str> + 'static>(&mut self, arguments: &[S]) -> Result<Vec<String>, Error> {
-        let mut cmd = Command::new(&self.bin);
-        if let Some(ref path) = self.config {
-            cmd.arg("--config");
-            cmd.arg(path);
-        }
-        let output = cmd.args(arguments.iter().map(|s| s.as_ref())).output()?;
-        if !output.status.success() {
-            return Err(Error::CmdExec(
-                String::from_utf8_lossy(&output.stderr).to_string(),
-            ));
-        }
-        let output = str::from_utf8(&output.stdout)?;
-        Ok(output.split('\n').map(|s| s.to_string()).collect())
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use mockall::predicate;

src/library/mod.rs

@@ -60,26 +60,26 @@ impl Query {
 /// Error type for library calls.
 #[derive(Debug, PartialEq, Eq)]
 pub enum Error {
-    /// The underlying library failed to execute a command.
+    /// The library's executor failed.
-    CmdExec(String),
+    Executor(String),
-    /// The underlying library returned invalid data.
+    /// The library experienced an I/O error.
-    Invalid(String),
-    /// The underlying library experienced an I/O error.
     Io(String),
-    /// The underlying library failed to parse an integer.
+    /// The library received invalid data.
+    Invalid(String),
+    /// The library failed to parse an integer.
     ParseInt(String),
-    /// The underlying library failed to parse a UTF-8 string.
+    /// The library failed to parse a UTF-8 string.
     Utf8(String),
 }
 
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            Self::CmdExec(ref s) => write!(f, "the library failed to execute a command: {s}"),
+            Self::Executor(ref s) => write!(f, "the library's executor failed: {s}"),
-            Self::Invalid(ref s) => write!(f, "the library received invalid data: {s}"),
             Self::Io(ref s) => write!(f, "the library experienced an I/O error: {s}"),
-            Self::ParseInt(ref s) => write!(f, "the library received an invalid integer: {s}"),
+            Self::Invalid(ref s) => write!(f, "the library received invalid data: {s}"),
-            Self::Utf8(ref s) => write!(f, "the library received invalid UTF-8: {s}"),
+            Self::ParseInt(ref s) => write!(f, "the library failed to parse an integer: {s}"),
+            Self::Utf8(ref s) => write!(f, "the library failed to parse a UTF-8 string: {s}"),
         }
     }
 }
@@ -133,21 +133,21 @@ mod tests {
 
     #[test]
     fn errors() {
-        let cmd_err = Error::CmdExec(String::from("CmdExec"));
+        let exe_err = Error::Executor(String::from("Executor"));
-        let inv_err = Error::Invalid(String::from("Invalid"));
         let io_err: Error = io::Error::new(io::ErrorKind::Interrupted, "Interrupted").into();
+        let inv_err = Error::Invalid(String::from("Invalid"));
         let int_err: Error = "five".parse::<u32>().unwrap_err().into();
         let utf_err: Error = std::str::from_utf8(b"\xe2\x28\xa1").unwrap_err().into();
 
-        assert!(!cmd_err.to_string().is_empty());
+        assert!(!exe_err.to_string().is_empty());
-        assert!(!inv_err.to_string().is_empty());
         assert!(!io_err.to_string().is_empty());
+        assert!(!inv_err.to_string().is_empty());
         assert!(!int_err.to_string().is_empty());
         assert!(!utf_err.to_string().is_empty());
 
-        assert!(!format!("{:?}", cmd_err).is_empty());
+        assert!(!format!("{:?}", exe_err).is_empty());
-        assert!(!format!("{:?}", inv_err).is_empty());
         assert!(!format!("{:?}", io_err).is_empty());
+        assert!(!format!("{:?}", inv_err).is_empty());
         assert!(!format!("{:?}", int_err).is_empty());
         assert!(!format!("{:?}", utf_err).is_empty());
     }

src/main.rs

@@ -1,14 +1,22 @@
-use ratatui::backend::CrosstermBackend;
-use ratatui::Terminal;
-use std::io;
 use std::path::PathBuf;
+use std::{ffi::OsString, io};
 
+use ratatui::{backend::CrosstermBackend, Terminal};
 use structopt::StructOpt;
 
 use musichoard::{
     collection::MhCollectionManager,
-    database::json::{JsonDatabase, JsonDatabaseFileBackend},
+    database::{
-    library::beets::{BeetsLibrary, BeetsLibraryCommandExecutor},
+        json::{backend::JsonDatabaseFileBackend, JsonDatabase},
+        Database,
+    },
+    library::{
+        beets::{
+            executor::{BeetsLibraryProcessExecutor, BeetsLibrarySshExecutor},
+            BeetsLibrary,
+        },
+        Library,
+    },
 };
 
 mod tui;
@@ -19,35 +27,22 @@ use tui::{
 
 #[derive(StructOpt)]
 struct Opt {
-    #[structopt(
+    #[structopt(long = "ssh", name = "beets SSH URI")]
-        short = "b",
+    beets_ssh_uri: Option<OsString>,
-        long = "beets",
+
-        name = "beets config file path",
+    #[structopt(long = "beets", name = "beets config file path")]
-        parse(from_os_str)
+    beets_config_file_path: Option<OsString>,
-    )]
-    beets_config_file_path: Option<PathBuf>,
 
     #[structopt(
-        short = "d",
         long = "database",
         name = "database file path",
-        default_value = "database.json",
+        default_value = "database.json"
-        parse(from_os_str)
     )]
     database_file_path: PathBuf,
 }
 
-fn main() {
+fn with<LIB: Library, DB: Database>(lib: LIB, db: DB) {
-    // Create the application.
+    let collection_manager = MhCollectionManager::new(lib, db);
-    let opt = Opt::from_args();
-
-    let beets = BeetsLibrary::new(
-        BeetsLibraryCommandExecutor::default().config(opt.beets_config_file_path.as_deref()),
-    );
-
-    let database = JsonDatabase::new(JsonDatabaseFileBackend::new(&opt.database_file_path));
-
-    let collection_manager = MhCollectionManager::new(beets, database);
 
     // Initialize the terminal user interface.
     let backend = CrosstermBackend::new(io::stdout());
@@ -65,6 +60,22 @@ fn main() {
     Tui::run(terminal, app, ui, handler, listener).expect("failed to run tui");
 }
 
+fn main() {
+    // Create the application.
+    let opt = Opt::from_args();
+
+    if let Some(uri) = opt.beets_ssh_uri {
+        let uri = uri.into_string().expect("invalid SSH URI");
+        let lib_exec = BeetsLibrarySshExecutor::new(uri).expect("failed to initialise beets");
+        let db_exec = JsonDatabaseFileBackend::new(&opt.database_file_path);
+        with(BeetsLibrary::new(lib_exec), JsonDatabase::new(db_exec));
+    } else {
+        let lib_exec = BeetsLibraryProcessExecutor::default().config(opt.beets_config_file_path);
+        let db_exec = JsonDatabaseFileBackend::new(&opt.database_file_path);
+        with(BeetsLibrary::new(lib_exec), JsonDatabase::new(db_exec));
+    }
+}
+
 #[cfg(test)]
 #[macro_use]
 mod testlib;

tests/database/json.rs

@@ -2,7 +2,7 @@ use std::{fs, path::PathBuf};
 
 use musichoard::{
     database::{
-        json::{JsonDatabase, JsonDatabaseFileBackend},
+        json::{backend::JsonDatabaseFileBackend, JsonDatabase},
         Database,
     },
     Artist,

tests/library/beets.rs

@@ -8,7 +8,7 @@ use once_cell::sync::Lazy;
 
 use musichoard::{
     library::{
-        beets::{BeetsLibrary, BeetsLibraryCommandExecutor},
+        beets::{executor::BeetsLibraryProcessExecutor, BeetsLibrary},
         Field, Library, Query,
     },
     Artist,
@@ -16,17 +16,17 @@ use musichoard::{
 
 use crate::COLLECTION;
 
-static BEETS_EMPTY_CONFIG: Lazy<Arc<Mutex<BeetsLibrary<BeetsLibraryCommandExecutor>>>> =
+static BEETS_EMPTY_CONFIG: Lazy<Arc<Mutex<BeetsLibrary<BeetsLibraryProcessExecutor>>>> =
     Lazy::new(|| {
         Arc::new(Mutex::new(BeetsLibrary::new(
-            BeetsLibraryCommandExecutor::default(),
+            BeetsLibraryProcessExecutor::default(),
         )))
     });
 
-static BEETS_TEST_CONFIG: Lazy<Arc<Mutex<BeetsLibrary<BeetsLibraryCommandExecutor>>>> =
+static BEETS_TEST_CONFIG: Lazy<Arc<Mutex<BeetsLibrary<BeetsLibraryProcessExecutor>>>> =
     Lazy::new(|| {
         Arc::new(Mutex::new(BeetsLibrary::new(
-            BeetsLibraryCommandExecutor::default().config(Some(
+            BeetsLibraryProcessExecutor::default().config(Some(
                 &fs::canonicalize("./tests/files/library/config.yml").unwrap(),
             )),
         )))
@@ -45,7 +45,7 @@ fn test_no_config_list() {
 
 #[test]
 fn test_invalid_config() {
-    let mut beets = BeetsLibrary::new(BeetsLibraryCommandExecutor::default().config(Some(
+    let mut beets = BeetsLibrary::new(BeetsLibraryProcessExecutor::default().config(Some(
         &PathBuf::from("./tests/files/library/config-does-not-exist.yml"),
     )));