pkh/src/context/unshare.rs

use super::api::{Context, ContextCommand, ContextDriver};
use log::debug;
use std::io;
use std::path::{Path, PathBuf};
use std::sync::Arc;

pub struct UnshareDriver {
    pub path: String,
    pub parent: Option<Arc<super::api::Context>>,
}

/// Recursively copy a directory and all its contents
fn copy_dir_recursive(src: &Path, dest: &Path) -> io::Result<()> {
    // Create the destination directory
    std::fs::create_dir_all(dest)?;

    // Iterate through the source directory
    for entry in std::fs::read_dir(src)? {
        let entry = entry?;
        let src_path = entry.path();
        let dest_path = dest.join(entry.file_name());

        if src_path.is_dir() {
            // Recursively copy subdirectories
            copy_dir_recursive(&src_path, &dest_path)?;
        } else {
            // Copy files
            std::fs::copy(&src_path, &dest_path)?;
        }
    }

    Ok(())
}

impl ContextDriver for UnshareDriver {
    fn ensure_available(&self, src: &Path, dest_root: &str) -> io::Result<PathBuf> {
        // Construct the destination path inside the chroot
        let dest_dir = Path::new(&self.path).join(dest_root.trim_start_matches('/'));
        debug!(
            "unshare/ensure_available: copy '{}' to '{}'",
            src.display(),
            dest_dir.display()
        );

        // Ensure the destination directory exists
        std::fs::create_dir_all(&dest_dir)?;

        // Get the filename from the source path
        let filename = src
            .file_name()
            .ok_or_else(|| io::Error::new(io::ErrorKind::InvalidInput, "Invalid source path"))?;

        // Construct the full destination path
        let dest_path = dest_dir.join(filename);

        // Copy the file or directory into the chroot
        if src.is_dir() {
            copy_dir_recursive(src, &dest_path)?;
            debug!(
                "Copied directory {} to {}",
                src.display(),
                dest_path.display()
            );
        } else {
            std::fs::copy(src, &dest_path)?;
            debug!("Copied file {} to {}", src.display(), dest_path.display());
        }

        // Return the path as it appears inside the chroot (without the chroot prefix)
        Ok(Path::new(dest_root).join(filename))
    }

    fn retrieve_path(&self, _src: &Path, _dest: &Path) -> io::Result<()> {
        // TODO: Implement chroot file retrieval logic
        Err(io::Error::new(
            io::ErrorKind::Unsupported,
            "retrieve_path not yet implemented for chroot",
        ))
    }

    fn list_files(&self, _path: &Path) -> io::Result<Vec<PathBuf>> {
        // TODO: Implement chroot file listing logic
        Err(io::Error::new(
            io::ErrorKind::Unsupported,
            "list_files not yet implemented for chroot",
        ))
    }

    fn run(
        &self,
        program: &str,
        args: &[String],
        env: &[(String, String)],
        cwd: Option<&str>,
    ) -> io::Result<std::process::ExitStatus> {
        self.command(program, args, env, cwd).status()
    }

    fn run_output(
        &self,
        program: &str,
        args: &[String],
        env: &[(String, String)],
        cwd: Option<&str>,
    ) -> io::Result<std::process::Output> {
        self.command(program, args, env, cwd).output()
    }

    fn create_temp_dir(&self) -> io::Result<String> {
        // Create a temporary directory inside the chroot
        let timestamp = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_secs();

        let work_dir_name = format!("pkh-build-{}", timestamp);
        let work_dir_inside_chroot = format!("/tmp/{}", work_dir_name);

        // Create the directory on the host filesystem
        let host_path = Path::new(&self.path).join("tmp").join(&work_dir_name);
        std::fs::create_dir_all(&host_path)?;

        debug!(
            "Created work directory: {} (host: {})",
            work_dir_inside_chroot,
            host_path.display()
        );

        // Return the path as it appears inside the chroot
        Ok(work_dir_inside_chroot)
    }

    fn copy_path(&self, src: &Path, dest: &Path) -> io::Result<()> {
        let host_src = Path::new(&self.path).join(src.to_string_lossy().trim_start_matches('/'));
        let host_dest = Path::new(&self.path).join(dest.to_string_lossy().trim_start_matches('/'));
        self.parent().copy_path(&host_src, &host_dest)
    }

    fn read_file(&self, path: &Path) -> io::Result<String> {
        let host_path = Path::new(&self.path).join(path.to_string_lossy().trim_start_matches('/'));
        self.parent().read_file(&host_path)
    }

    fn write_file(&self, path: &Path, content: &str) -> io::Result<()> {
        let host_path = Path::new(&self.path).join(path.to_string_lossy().trim_start_matches('/'));
        self.parent().write_file(&host_path, content)
    }
}

impl UnshareDriver {
    fn parent(&self) -> &Context {
        self.parent
            .as_ref()
            .expect("UnshareDriver requires a parent context")
    }

    fn command(
        &self,
        program: &str,
        args: &[String],
        env: &[(String, String)],
        cwd: Option<&str>,
    ) -> ContextCommand<'_> {
        let mut cmd = self.parent().command("sudo");
        cmd.args(env.iter().map(|(k, v)| format!("{k}={v}")));

        cmd.arg("unshare").arg("-R").arg(&self.path);

        if let Some(dir) = cwd {
            cmd.arg("-w").arg(dir);
        }

        cmd.arg(program).args(args);

        cmd
    }
}