dkl/src/apply.rs

use eyre::{Result, format_err};
use log::info;
use std::path::Path;
use tokio::fs;

use crate::File;

pub async fn files(files: &[File], root: &str, dry_run: bool) -> Result<()> {
    for f in files {
        if let Err(e) = file(f, root, dry_run).await {
            return Err(format_err!("{}: {e}", f.path));
        }
    }
    Ok(())
}

pub async fn file(file: &File, root: &str, dry_run: bool) -> Result<()> {
    let path = chroot(root, &file.path);
    let path = Path::new(&path);

    if !dry_run && let Some(parent) = path.parent() {
        fs::create_dir_all(parent).await?;
    }

    let kind = file.kind();
    let content = kind.content()?;

    use crate::{FileKind as K};
    match kind.as_ref() {
        K::Skip => {
            info!("{}: kind is skip", file.path);
            return Ok(());
        }
        K::Content(_) | K::Content64(_) | K::Parts(_) => {
            let content = content.expect("this file kind should have content");
            if dry_run {
                info!(
                    "would create {} ({} bytes)",
                    file.path,
                    content.len()
                );
            } else {
                fs::write(path, &content).await?;
            }
        }
        K::Dir => {
            if dry_run {
                info!("would create {} (directory)", file.path);
            } else {
                fs::create_dir(path).await?;
            }
        }
        K::Symlink(tgt) => {
            if dry_run {
                info!("would create {} (symlink to {})", file.path, tgt);
            } else {
                let _ = fs::remove_file(path).await; // we're ln --force
                fs::symlink(tgt, path).await?;
            }
        }
    }

    if dry_run {
        return Ok(());
    }

    if !file.is_symlink() {
        set_perms(path, file.mode).await?;
    }

    info!("created {}", file.path);
    Ok(())
}

pub async fn set_perms(path: impl AsRef<Path>, mode: Option<u32>) -> std::io::Result<()> {
    if let Some(mode) = mode.filter(|m| *m != 0) {
        use std::os::unix::fs::PermissionsExt;
        let mode = std::fs::Permissions::from_mode(mode);
        fs::set_permissions(path, mode).await?;
    }
    Ok(())
}

pub fn chroot(root: &str, path: &str) -> String {
    format!("{root}/{}", path.trim_start_matches(|c| c == '/'))
}