promkit/core/tree/node.rs
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use std::{fs, path};
/// Represents the kind of a node in a tree structure.
///
/// This enum is used to distinguish between nodes that are currently
/// visible in their "folded" state and those that are "unfolded" to reveal
/// their children, if any.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum Kind {
/// Represents a node that is folded (i.e., its children are not currently visible).
/// - `id`: A unique identifier for the node.
/// - `path`: The path from the root to this node, represented as a sequence of indices.
Folded { id: String, path: Path },
/// Represents a node that is unfolded (i.e., its children are currently visible).
/// - `id`: A unique identifier for the node.
/// - `path`: The path from the root to this node, represented as a sequence of indices.
Unfolded { id: String, path: Path },
}
/// A type alias for a path in the tree, represented as a sequence of indices.
pub type Path = Vec<usize>;
/// Represents a node within a tree structure.
///
/// A node can either be a `NonLeaf`, containing children and a visibility flag,
/// or a `Leaf`, representing an end node without children.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum Node {
/// Represents a non-leaf node, which can contain child nodes.
/// - `id`: A unique identifier for the node.
/// - `children`: A vector of child nodes.
/// - `children_visible`: A boolean indicating if the children of this node are visible.
NonLeaf {
id: String,
children: Vec<Node>,
children_visible: bool,
},
/// Represents a leaf node, which does not contain any child nodes.
/// - `id`: A unique identifier for the leaf node.
Leaf(String),
}
impl TryFrom<&path::PathBuf> for Node {
/// Attempts to create a `Node` from a given directory path.
///
/// This method constructs a `Node::NonLeaf` representing the directory specified by `dir_path`.
/// It recursively explores the directory, converting subdirectories into `Node::NonLeaf` instances
/// and files into `Node::Leaf` instances. Directories and files are kept in separate lists initially,
/// then combined with all directories first, followed by files. Both lists are sorted alphabetically
/// before merging. The resulting tree structure reflects the hierarchy of files and directories within
/// `dir_path`, with directories listed before files, both in alphabetical order.
///
/// # Parameters
/// - `dir_path`: A reference to a `PathBuf` representing the directory to be converted into a `Node`.
///
/// # Returns
/// A `Result` containing the root `Node` of the constructed tree if successful, or an `Error` if the
/// directory cannot be read or if any file name cannot be converted to a string.
///
/// # Errors
/// This method returns an `Error` if:
/// - The path does not exist or is not a directory.
/// - There is an error reading the directory contents.
/// - A file name cannot be converted to a UTF-8 string.
type Error = anyhow::Error;
fn try_from(dir_path: &path::PathBuf) -> anyhow::Result<Self> {
let mut directories = Vec::new();
let mut files = Vec::new();
if dir_path.is_dir() {
for entry in fs::read_dir(dir_path)? {
let path = entry?.path();
if path.is_dir() {
directories.push(Node::try_from(&path)?);
} else if path.is_file() {
files.push(Node::Leaf(
path.file_name()
.and_then(|name| name.to_str())
.ok_or_else(|| {
std::io::Error::new(
std::io::ErrorKind::Other,
"Failed to convert file name to string",
)
})?
.to_string(),
));
}
}
}
directories.sort_by(|a, b| a.id().cmp(b.id()));
files.sort_by(|a, b| a.id().cmp(b.id()));
let mut children = directories;
children.extend(files);
Ok(Node::NonLeaf {
id: dir_path
.file_name()
.and_then(|name| name.to_str())
.ok_or_else(|| {
std::io::Error::new(
std::io::ErrorKind::Other,
"Failed to convert directory name to string",
)
})?
.to_string(),
children,
children_visible: false,
})
}
}
impl Node {
fn id(&self) -> &String {
match self {
Node::NonLeaf { id, .. } => id,
Node::Leaf(id) => id,
}
}
/// Flattens the tree structure into a vector of `Kind`, including only visible nodes.
///
/// This method performs a depth-first search (DFS) to traverse the tree and collect
/// nodes into a vector. Each node is represented as either `Kind::Folded` or `Kind::Unfolded`
/// based on its visibility and whether it has children.
///
/// Returns:
/// - Vec<Kind>: A vector of `Kind` representing the visible nodes in the tree.
pub fn flatten_visibles(&self) -> Vec<Kind> {
fn dfs(node: &Node, path: Path, ret: &mut Vec<Kind>) {
match node {
Node::NonLeaf {
id,
children,
children_visible,
} => {
if *children_visible {
ret.push(Kind::Unfolded {
id: id.clone(),
path: path.clone(),
});
for (index, child) in children.iter().enumerate() {
let mut new_path = path.clone();
new_path.push(index);
dfs(child, new_path, ret);
}
} else {
ret.push(Kind::Folded {
id: id.clone(),
path: path.clone(),
});
}
}
Node::Leaf(item) => {
ret.push(Kind::Folded {
id: item.clone(),
path: path.clone(),
});
}
}
}
let mut ret = Vec::new();
dfs(self, Vec::new(), &mut ret);
ret
}
/// Toggles the visibility of the children of the node specified by the given path.
///
/// Parameters:
/// - path: &Path - A reference to a vector of usize, representing the path to the target node.
///
/// This method modifies the tree in-place. If the target node is found and is a `NonLeaf`,
/// its `children_visible` field is toggled.
pub fn toggle(&mut self, path: &Path) {
if let Some(Node::NonLeaf {
children_visible, ..
}) = self.get_mut(path)
{
*children_visible = !*children_visible;
}
}
/// Retrieves the IDs of all nodes along the path to a specified node.
///
/// Parameters:
/// - path: &Path - A reference to a vector of usize, representing the path to the target node.
///
/// Returns:
/// - Vec<String>: A vector of String IDs representing the nodes along the path to the target node.
pub fn get_waypoints(&self, path: &Path) -> Vec<String> {
let mut ids = Vec::new();
let mut node = self;
for &index in path {
match node {
Node::NonLeaf { id, children, .. } => {
ids.push(id.clone());
if let Some(child) = children.get(index) {
node = child;
} else {
break;
}
}
Node::Leaf(id) => {
ids.push(id.clone());
break;
}
}
}
ids
}
/// Retrieves a reference to the node specified by the given path.
///
/// Parameters:
/// - path: &Path - A reference to a vector of usize, representing the path to the target node.
///
/// Returns:
/// - Option<&Node>: An option containing a reference to the target node if found, or None otherwise.
pub fn get(&self, path: &Path) -> Option<&Node> {
let mut node = self;
for seg in path {
match node {
Node::NonLeaf {
id: _,
children,
children_visible: _,
} => {
if let Some(next_node) = children.get(*seg) {
node = next_node;
} else {
return None;
}
}
Node::Leaf(_) => {
return None;
}
}
}
Some(node)
}
/// Retrieves a mutable reference to the node specified by the given path.
///
/// Parameters:
/// - path: &Path - A reference to a vector of usize, representing the path to the target node.
///
/// Returns:
/// - Option<&mut Node>: An option containing a mutable reference to the target node if found, or None otherwise.
pub fn get_mut(&mut self, path: &Path) -> Option<&mut Node> {
let mut node = self;
for seg in path {
match node {
Node::NonLeaf {
id: _,
children,
children_visible: _,
} => {
if let Some(next_node) = children.get_mut(*seg) {
node = next_node;
} else {
return None;
}
}
Node::Leaf(_) => {
return None;
}
}
}
Some(node)
}
}
#[cfg(test)]
mod test {
use super::*;
fn create_test_node() -> Node {
Node::NonLeaf {
id: "root".into(),
children: vec![
Node::NonLeaf {
id: "a".into(),
children: vec![Node::Leaf("aa".into()), Node::Leaf("ab".into())],
children_visible: true,
},
Node::Leaf("b".into()),
Node::Leaf("c".into()),
],
children_visible: true,
}
}
fn as_nonleaf(node: &Node) -> Option<(&String, &Vec<Node>, bool)> {
match node {
Node::NonLeaf {
id,
children,
children_visible,
} => Some((id, children, *children_visible)),
_ => None,
}
}
mod toggle {
use super::*;
#[test]
fn test() {
let mut node = create_test_node();
node.toggle(&vec![]);
assert!(!as_nonleaf(node.get(&vec![]).unwrap()).unwrap().2);
}
}
mod flatten_visibles {
use super::*;
#[test]
fn test() {
let node = create_test_node();
assert_eq!(
vec![
Kind::Unfolded {
id: "root".into(),
path: vec![],
},
Kind::Unfolded {
id: "a".into(),
path: vec![0],
},
Kind::Folded {
id: "aa".into(),
path: vec![0, 0],
},
Kind::Folded {
id: "ab".into(),
path: vec![0, 1],
},
Kind::Folded {
id: "b".into(),
path: vec![1],
},
Kind::Folded {
id: "c".into(),
path: vec![2],
},
],
node.flatten_visibles(),
);
}
#[test]
fn test_after_toggle() {
let mut node = create_test_node();
node.toggle(&vec![]);
assert_eq!(
vec![Kind::Folded {
id: "root".into(),
path: vec![],
},],
node.flatten_visibles(),
);
}
}
}