Implement the shared automation CLI.

crates/bds-core/src/engine/cli_launcher.rs

@@ -0,0 +1,73 @@
+use std::path::{Path, PathBuf};
+
+use crate::engine::{EngineError, EngineResult};
+
+/// Install a recoverable launcher pointing at a packaged `bds-cli` binary.
+/// Existing unrelated files are never overwritten.
+pub fn install_launcher(executable: &Path, home_dir: &Path) -> EngineResult<PathBuf> {
+    if !executable.is_file() {
+        return Err(EngineError::Validation(format!(
+            "installing the CLI requires the packaged bds-cli executable (not found at {})",
+            executable.display()
+        )));
+    }
+    let bin_dir = home_dir.join(".local/bin");
+    std::fs::create_dir_all(&bin_dir)?;
+    let target = bin_dir.join(if cfg!(windows) {
+        "bds-cli.exe"
+    } else {
+        "bds-cli"
+    });
+    if target.exists() {
+        let existing = target.canonicalize().ok();
+        let source = executable.canonicalize()?;
+        if existing.as_ref() != Some(&source) {
+            return Err(EngineError::Conflict(format!(
+                "refusing to overwrite existing launcher at {}",
+                target.display()
+            )));
+        }
+        return Ok(target);
+    }
+
+    #[cfg(unix)]
+    std::os::unix::fs::symlink(executable.canonicalize()?, &target)?;
+    #[cfg(windows)]
+    std::fs::copy(executable, &target)?;
+    Ok(target)
+}
+
+/// Resolve the CLI shipped beside the desktop executable and install it.
+pub fn install_packaged_launcher(home_dir: &Path) -> EngineResult<PathBuf> {
+    let app = std::env::current_exe()?;
+    let cli = app.with_file_name(if cfg!(windows) {
+        "bds-cli.exe"
+    } else {
+        "bds-cli"
+    });
+    install_launcher(&cli, home_dir)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn install_is_idempotent_and_never_overwrites_an_unrelated_file() {
+        let root = tempfile::tempdir().unwrap();
+        let executable = root.path().join("packaged-bds-cli");
+        std::fs::write(&executable, b"binary").unwrap();
+        let home = root.path().join("home");
+        let target = install_launcher(&executable, &home).unwrap();
+        assert_eq!(
+            target.canonicalize().unwrap(),
+            executable.canonicalize().unwrap()
+        );
+        assert_eq!(install_launcher(&executable, &home).unwrap(), target);
+
+        std::fs::remove_file(&target).unwrap();
+        std::fs::write(&target, b"mine").unwrap();
+        assert!(install_launcher(&executable, &home).is_err());
+        assert_eq!(std::fs::read(&target).unwrap(), b"mine");
+    }
+}