From 5da1310696ef807a1d83c0a79c21ebe34184d106 Mon Sep 17 00:00:00 2001
From: xiuxiu62 <jacremer@live.com>
Date: Tue, 5 Oct 2021 12:55:33 -0700
Subject: [PATCH] add fs utils

---
 crates/nu-command/src/filesystem/mod.rs  |  3 +
 crates/nu-command/src/filesystem/util.rs | 82 ++++++++++++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 crates/nu-command/src/filesystem/util.rs

diff --git a/crates/nu-command/src/filesystem/mod.rs b/crates/nu-command/src/filesystem/mod.rs
index 90b697fcd..2d2212766 100644
--- a/crates/nu-command/src/filesystem/mod.rs
+++ b/crates/nu-command/src/filesystem/mod.rs
@@ -1,7 +1,10 @@
 mod cd;
+mod cp;
 mod ls;
 mod mv;
+mod util;
 
 pub use cd::Cd;
+pub use cp::Cp;
 pub use ls::Ls;
 pub use mv::Mv;
diff --git a/crates/nu-command/src/filesystem/util.rs b/crates/nu-command/src/filesystem/util.rs
new file mode 100644
index 000000000..86a0bd4c9
--- /dev/null
+++ b/crates/nu-command/src/filesystem/util.rs
@@ -0,0 +1,82 @@
+use std::path::{Path, PathBuf};
+
+use nu_path::canonicalize_with;
+use nu_protocol::ShellError;
+
+#[derive(Default)]
+pub struct FileStructure {
+    pub resources: Vec<Resource>,
+}
+
+impl FileStructure {
+    pub fn new() -> FileStructure {
+        FileStructure { resources: vec![] }
+    }
+
+    #[allow(dead_code)]
+    pub fn contains_more_than_one_file(&self) -> bool {
+        self.resources.len() > 1
+    }
+
+    #[allow(dead_code)]
+    pub fn contains_files(&self) -> bool {
+        !self.resources.is_empty()
+    }
+
+    pub fn paths_applying_with<F>(
+        &mut self,
+        to: F,
+    ) -> Result<Vec<(PathBuf, PathBuf)>, Box<dyn std::error::Error>>
+    where
+        F: Fn((PathBuf, usize)) -> Result<(PathBuf, PathBuf), Box<dyn std::error::Error>>,
+    {
+        self.resources
+            .iter()
+            .map(|f| (PathBuf::from(&f.location), f.at))
+            .map(|f| to(f))
+            .collect()
+    }
+
+    pub fn walk_decorate(&mut self, start_path: &Path) -> Result<(), ShellError> {
+        self.resources = Vec::<Resource>::new();
+        self.build(start_path, 0)?;
+        self.resources.sort();
+
+        Ok(())
+    }
+
+    fn build(&mut self, src: &Path, lvl: usize) -> Result<(), ShellError> {
+        let source = canonicalize_with(src, std::env::current_dir()?)?;
+
+        if source.is_dir() {
+            for entry in std::fs::read_dir(src)? {
+                let entry = entry?;
+                let path = entry.path();
+
+                if path.is_dir() {
+                    self.build(&path, lvl + 1)?;
+                }
+
+                self.resources.push(Resource {
+                    location: path.to_path_buf(),
+                    at: lvl,
+                });
+            }
+        } else {
+            self.resources.push(Resource {
+                location: source,
+                at: lvl,
+            });
+        }
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, Eq, Ord, PartialEq, PartialOrd)]
+pub struct Resource {
+    pub at: usize,
+    pub location: PathBuf,
+}
+
+impl Resource {}