stash: add multicall support for stash-copy and stash-paste

We can finally tell the users that they can uninstall `wl-copy` and
`wl-paste` on their systems. Stash now somewhat supports being invoked
under the names `stash-copy` and `stash-paste` to fully reimplement the
functionality of `wl-copy` and `wl-paste` respectively.

A build wrapper has been added generate symlinks for `stash-copy`, `stash-paste`,
`wl-copy`, and `wl-paste`. `wl-copy` and `wl-paste` links are provided
only for backwards compatibility, but they will not go away anytime
soon.

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I6a6a6964463b35427cb720fbab68b252944cc90c

.gitignore

@@ -9,6 +9,7 @@
 # Rust/Cargo
 !/Cargo.lock
 !/Cargo.toml
+!/build.rs
 
 # Configuration files
 !/.config/

build.rs

@@ -0,0 +1,56 @@
+use std::{env, fs, path::Path};
+
+/// List of multicall symlinks to create (name, target)
+const MULTICALL_LINKS: &[&str] =
+  &["stash-copy", "stash-paste", "wl-copy", "wl-paste"];
+
+fn main() {
+  // Only run on Unix-like systems
+  #[cfg(not(unix))]
+  {
+    println!(
+      "cargo:warning=Multicall symlinks are only supported on Unix-like \
+       systems."
+    );
+    return;
+  }
+
+  // OUT_DIR is something like .../target/debug/build/<pkg>/out
+  // We want .../target/debug or .../target/release
+  let out_dir = env::var("OUT_DIR").expect("OUT_DIR not set");
+  let bin_dir = Path::new(&out_dir)
+    .ancestors()
+    .nth(3)
+    .expect("Failed to find binary dir");
+
+  // Path to the main stash binary
+  let stash_bin = bin_dir.join("stash");
+
+  // Create symlinks for each multicall binary
+  for link in MULTICALL_LINKS {
+    let link_path = bin_dir.join(link);
+    // Remove existing symlink or file if present
+    let _ = fs::remove_file(&link_path);
+    #[cfg(unix)]
+    {
+      use std::os::unix::fs::symlink;
+      match symlink(&stash_bin, &link_path) {
+        Ok(()) => {
+          println!(
+            "cargo:warning=Created symlink: {} -> {}",
+            link_path.display(),
+            stash_bin.display()
+          );
+        },
+        Err(e) => {
+          println!(
+            "cargo:warning=Failed to create symlink {} -> {}: {}",
+            link_path.display(),
+            stash_bin.display(),
+            e
+          );
+        },
+      }
+    }
+  }
+}

src/main.rs

@@ -10,6 +10,7 @@ use inquire::Confirm;
 
 mod commands;
 mod db;
+mod multicall;
 #[cfg(feature = "use-toplevel")] mod wayland;
 
 use crate::commands::{
@@ -129,6 +130,13 @@ fn report_error<T>(
 
 #[allow(clippy::too_many_lines)] // whatever
 fn main() {
+   // Multicall dispatch: stash-copy, stash-paste, wl-copy, wl-paste
+  if crate::multicall::multicall_dispatch() {
+    // If handled, exit immediately
+    std::process::exit(0);
+  }
+
+  // If not multicall, proceed with normal CLI handling
   smol::block_on(async {
     let cli = Cli::parse();
     env_logger::Builder::new()

src/multicall.rs

@@ -0,0 +1,288 @@
+use std::io::{self, Read, Write};
+
+use clap::{ArgAction, Parser};
+use wl_clipboard_rs::paste::{
+  ClipboardType,
+  Error,
+  MimeType,
+  Seat,
+  get_contents,
+};
+
+/// Dispatch multicall binary logic based on argv[0].
+/// Returns true if a multicall command was handled and the process should exit.
+pub fn multicall_dispatch() -> bool {
+  let argv0 = std::env::args().next().unwrap_or_default();
+  let base = std::path::Path::new(&argv0)
+    .file_name()
+    .and_then(|s| s.to_str())
+    .unwrap_or("");
+  match base {
+    "stash-copy" | "wl-copy" => {
+      multicall_stash_copy();
+      true
+    },
+    "stash-paste" | "wl-paste" => {
+      multicall_stash_paste();
+      true
+    },
+    _ => false,
+  }
+}
+
+#[allow(clippy::too_many_lines)]
+fn multicall_stash_copy() {
+  use clap::{ArgAction, Parser};
+  use wl_clipboard_rs::{
+    copy::{ClipboardType, MimeType, Options, ServeRequests, Source},
+    utils::{PrimarySelectionCheckError, is_primary_selection_supported},
+  };
+  #[derive(Parser, Debug)]
+  #[command(
+    name = "stash-copy",
+    about = "Copy clipboard contents on Wayland.",
+    version,
+    disable_help_subcommand = true
+  )]
+  #[allow(clippy::struct_excessive_bools)]
+  struct Args {
+    /// Serve only a single paste request and then exit
+    #[arg(short = 'o', long = "paste-once", action = ArgAction::SetTrue)]
+    paste_once:                      bool,
+    /// Stay in the foreground instead of forking
+    #[arg(short = 'f', long = "foreground", action = ArgAction::SetTrue)]
+    foreground:                      bool,
+    /// Clear the clipboard instead of copying
+    #[arg(short = 'c', long = "clear", action = ArgAction::SetTrue)]
+    clear:                           bool,
+    /// Use the \"primary\" clipboard
+    #[arg(short = 'p', long = "primary", action = ArgAction::SetTrue)]
+    primary:                         bool,
+    /// Use the regular clipboard
+    #[arg(short = 'r', long = "regular", action = ArgAction::SetTrue)]
+    regular:                         bool,
+    /// Trim the trailing newline character before copying
+    #[arg(short = 'n', long = "trim-newline", action = ArgAction::SetTrue)]
+    trim_newline:                    bool,
+    /// Pick the seat to work with
+    #[arg(short = 's', long = "seat")]
+    seat:                            Option<String>,
+    /// Override the inferred MIME type for the content
+    #[arg(short = 't', long = "type")]
+    mime_type:                       Option<String>,
+    /// Enable verbose logging
+    #[arg(short = 'v', long = "verbose", action = ArgAction::Count)]
+    verbose:                         u8,
+    /// Check if primary selection is supported and exit
+    #[arg(long = "check-primary", action = ArgAction::SetTrue)]
+    check_primary:                   bool,
+    /// Do not offer additional text mime types (stash extension)
+    #[arg(long = "omit-additional-text-mime-types", action = ArgAction::SetTrue, hide = true)]
+    omit_additional_text_mime_types: bool,
+    /// Number of paste requests to serve before exiting (stash extension)
+    #[arg(short = 'x', long = "serve-requests", hide = true)]
+    serve_requests:                  Option<usize>,
+    /// Text to copy (if not given, read from stdin)
+    #[arg(value_name = "TEXT TO COPY", action = ArgAction::Append)]
+    text:                            Vec<String>,
+  }
+
+  let args = Args::parse();
+
+  if args.check_primary {
+    match is_primary_selection_supported() {
+      Ok(true) => {
+        log::info!("Primary selection is supported.");
+        std::process::exit(0);
+      },
+      Ok(false) => {
+        log::info!("Primary selection is NOT supported.");
+        std::process::exit(1);
+      },
+      Err(PrimarySelectionCheckError::NoSeats) => {
+        log::error!("Could not determine: no seats available.");
+        std::process::exit(2);
+      },
+      Err(PrimarySelectionCheckError::MissingProtocol) => {
+        log::error!("Data-control protocol not supported by compositor.");
+        std::process::exit(3);
+      },
+      Err(e) => {
+        log::error!("Error checking primary selection support: {e}");
+        std::process::exit(4);
+      },
+    }
+  }
+
+  let clipboard = if args.primary {
+    ClipboardType::Primary
+  } else {
+    ClipboardType::Regular
+  };
+
+  let mime_type = if let Some(mt) = args.mime_type.as_deref() {
+    if mt == "text" || mt == "text/plain" {
+      MimeType::Text
+    } else if mt == "autodetect" {
+      MimeType::Autodetect
+    } else {
+      MimeType::Specific(mt.to_string())
+    }
+  } else {
+    MimeType::Autodetect
+  };
+
+  let mut input: Vec<u8> = Vec::new();
+  if args.text.is_empty() {
+    if let Err(e) = std::io::stdin().read_to_end(&mut input) {
+      eprintln!("stash-copy: failed to read stdin: {e}");
+      std::process::exit(1);
+    }
+  } else {
+    input = args.text.join(" ").into_bytes();
+  }
+
+  let mut opts = Options::new();
+  opts.clipboard(clipboard);
+
+  if args.trim_newline {
+    opts.trim_newline(true);
+  }
+  if args.foreground {
+    opts.foreground(true);
+  }
+  if let Some(seat) = args.seat.as_deref() {
+    log::debug!(
+      "stash-copy: --seat is not supported by stash (using default seat: \
+       {seat})"
+    );
+  }
+  if args.omit_additional_text_mime_types {
+    opts.omit_additional_text_mime_types(true);
+  }
+  // --paste-once overrides serve-requests
+  if args.paste_once {
+    opts.serve_requests(ServeRequests::Only(1));
+  } else if let Some(n) = args.serve_requests {
+    opts.serve_requests(ServeRequests::Only(n));
+  }
+  // --clear
+  if args.clear {
+    // Clear clipboard by setting empty contents
+    if let Err(e) = opts.copy(Source::Bytes(Vec::new().into()), mime_type) {
+      log::error!("stash-copy: failed to clear clipboard: {e}");
+      std::process::exit(1);
+    }
+    return;
+  }
+  if let Err(e) = opts.copy(Source::Bytes(input.into()), mime_type) {
+    log::error!("stash-copy: failed to copy to clipboard: {e}");
+    std::process::exit(1);
+  }
+}
+
+fn multicall_stash_paste() {
+  #[derive(Parser, Debug)]
+  #[command(
+    name = "stash-paste",
+    about = "Paste clipboard contents on Wayland.",
+    version,
+    disable_help_subcommand = true
+  )]
+  struct Args {
+    /// List the offered MIME types instead of pasting
+    #[arg(short = 'l', long = "list-types", action = ArgAction::SetTrue)]
+    list_types: bool,
+    /// Use the "primary" clipboard
+    #[arg(short = 'p', long = "primary", action = ArgAction::SetTrue)]
+    primary:    bool,
+    /// Do not append a newline character
+    #[arg(short = 'n', long = "no-newline", action = ArgAction::SetTrue)]
+    no_newline: bool,
+    /// Pick the seat to work with
+    #[arg(short = 's', long = "seat")]
+    seat:       Option<String>,
+    /// Request the given MIME type instead of inferring the MIME type
+    #[arg(short = 't', long = "type")]
+    mime_type:  Option<String>,
+    /// Enable verbose logging
+    #[arg(short = 'v', long = "verbose", action = ArgAction::Count)]
+    verbose:    u8,
+  }
+
+  let args = Args::parse();
+
+  let clipboard = if args.primary {
+    ClipboardType::Primary
+  } else {
+    ClipboardType::Regular
+  };
+
+  if let Some(seat) = args.seat.as_deref() {
+    log::debug!(
+      "stash-paste: --seat is not supported by stash (using default seat: \
+       {seat})"
+    );
+  }
+
+  if args.list_types {
+    match get_contents(clipboard, Seat::Unspecified, MimeType::Text) {
+      Ok((_reader, available_types)) => {
+        print!("{available_types}");
+        std::process::exit(0);
+      },
+      Err(e) => {
+        log::error!("stash-paste: failed to list types: {e}");
+        std::process::exit(1);
+      },
+    }
+  }
+
+  let mime_type = match args.mime_type.as_deref() {
+    None | Some("text" | "autodetect") => MimeType::Text,
+    Some(other) => MimeType::Specific(other),
+  };
+
+  match get_contents(clipboard, Seat::Unspecified, mime_type) {
+    Ok((mut reader, _types)) => {
+      let mut out = io::stdout();
+      let mut buf = Vec::new();
+      match reader.read_to_end(&mut buf) {
+        Ok(n) => {
+          if n == 0 && args.no_newline {
+            std::process::exit(1);
+          }
+          let _ = out.write_all(&buf);
+          if !args.no_newline && !buf.ends_with(b"\n") {
+            let _ = out.write_all(b"\n");
+          }
+        },
+        Err(e) => {
+          log::error!("stash-paste: failed to read clipboard: {e}");
+          std::process::exit(1);
+        },
+      }
+    },
+    Err(Error::NoSeats) => {
+      log::error!(
+        "stash-paste: no seats available (is a Wayland compositor running?)"
+      );
+      std::process::exit(1);
+    },
+    Err(Error::ClipboardEmpty) => {
+      if args.no_newline {
+        std::process::exit(1);
+      }
+    },
+    Err(Error::NoMimeType) => {
+      log::error!(
+        "stash-paste: clipboard does not contain requested MIME type"
+      );
+      std::process::exit(1);
+    },
+    Err(e) => {
+      log::error!("stash-paste: clipboard error: {e}");
+      std::process::exit(1);
+    },
+  }
+}