1 files changed, 900 insertions, 14 deletions

diff --git a/src/main.rs b/src/main.rs
index f623450..9b17787 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,847 @@
 
 // TODO: rewrite all errors so they start with lower case
 
-pub mod depot {
+mod depot {
+    use std::{
+        collections::HashSet,
+        ffi::{OsStr, OsString},
+        ops::Index,
+        path::{Path, PathBuf},
+    };
+    use thiserror::Error;
+
+    use slotmap::{Key, SlotMap};
+
+    //pub type Result<T, E = DepotError> = std::result::Result<T, E>;
+    pub use anyhow::Result;
+    pub use disk::{read, write};
+
+    slotmap::new_key_type! {pub struct LinkID;}
+    slotmap::new_key_type! {struct NodeID;}
+
+    #[derive(Debug, Error)]
+    enum DepotError {
+        #[error("path must be relative")]
+        InvalidPath,
+        #[error("path must be relative and not empty")]
+        InvalidLinkPath,
+        #[error("{0}")]
+        LinkCreateError(#[from] LinkCreateError),
+    }
+
+    #[derive(Debug, Error)]
+    enum LinkCreateError {
+        #[error("an ancestor of this path is already linked")]
+        AncestorAlreadyLinked,
+    }
+
+    #[derive(Debug, Clone)]
+    struct Node {
+        comp: OsString,
+        parent: NodeID,
+        kind: NodeKind,
+    }
+
+    #[derive(Debug, Clone)]
+    enum NodeKind {
+        Link(LinkID),
+        Directory(HashSet<NodeID>),
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq)]
+    pub enum NodeSearchResult {
+        Found(NodeID),
+        /// the closest NodeID up the the search point.
+        NotFound(NodeID),
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq)]
+    pub enum DirNode {
+        Link(LinkID),
+        Directory(PathBuf),
+    }
+
+    #[derive(Debug, Clone, PartialEq, Eq)]
+    pub enum SearchResult {
+        Found(LinkID),
+        Ancestor(LinkID),
+        NotFound,
+    }
+
+    #[derive(Debug, Clone)]
+    struct Link {
+        origin: PathBuf,
+        destination: PathBuf,
+        origin_id: NodeID,
+    }
+
+    #[derive(Debug)]
+    pub struct LinkView<'a> {
+        link_id: LinkID,
+        depot: &'a Depot,
+    }
+
+    impl<'a> LinkView<'a> {
+        pub fn origin(&self) -> &Path {
+            &self.depot.links[self.link_id].origin
+        }
+
+        pub fn destination(&self) -> &Path {
+            &self.depot.links[self.link_id].destination
+        }
+    }
+
+    #[derive(Debug, Clone)]
+    struct DepotTree {
+        root: NodeID,
+        nodes: SlotMap<NodeID, Node>,
+    }
+
+    impl Default for DepotTree {
+        fn default() -> Self {
+            let mut nodes = SlotMap::<NodeID, Node>::default();
+            let root = nodes.insert(Node {
+                comp: Default::default(),
+                parent: Default::default(),
+                kind: NodeKind::Directory(Default::default()),
+            });
+            Self { root, nodes }
+        }
+    }
+
+    impl Index<NodeID> for DepotTree {
+        type Output = Node;
+
+        fn index(&self, index: NodeID) -> &Self::Output {
+            self.nodes.index(index)
+        }
+    }
+
+    impl DepotTree {
+        /// create a node of kind [`NodeKind::Link`].
+        pub fn link_create(&mut self, path: &Path, link_id: LinkID) -> Result<NodeID> {
+            debug_assert!(path_verify_link(path).is_ok());
+
+            let path_search_result = self.search(path);
+
+            // handle the error cases
+            match path_search_result {
+                NodeSearchResult::Found(node_id) => {
+                    let node = &self.nodes[node_id];
+                    match &node.kind {
+                        NodeKind::Link(_) => Err(anyhow::anyhow!("link already exists")),
+                        NodeKind::Directory(_) => {
+                            Err(anyhow::anyhow!("path already has links under it"))
+                        }
+                    }
+                }
+                NodeSearchResult::NotFound(ancestor_node_id) => {
+                    let ancestor_node = &self.nodes[ancestor_node_id];
+                    match &ancestor_node.kind {
+                        NodeKind::Link(_) => Err(anyhow::anyhow!(
+                            "an ancestor of this path is already linked"
+                        )),
+                        NodeKind::Directory(_) => Ok(()),
+                    }
+                }
+            }?;
+
+            // create the node
+            // unwrap: this is a verfied link path, it must have atleast one component
+            let filename = path.file_name().unwrap();
+            let parent_path = path_parent_or_empty(path);
+            let node_id = self.nodes.insert(Node {
+                comp: filename.to_owned(),
+                parent: Default::default(),
+                kind: NodeKind::Link(link_id),
+            });
+            let parent_id = self.directory_get_or_create(parent_path, node_id);
+            self.nodes[node_id].parent = parent_id;
+            Ok(node_id)
+        }
+
+        pub fn link_update_id(&mut self, node_id: NodeID, link_id: LinkID) {
+            let node = &mut self.nodes[node_id];
+            match &mut node.kind {
+                NodeKind::Link(lid) => *lid = link_id,
+                NodeKind::Directory(_) => unreachable!(),
+            }
+        }
+
+        /// attempts to moves a node of kind [`NodeKind::Link`] to `destination`.
+        pub fn link_move(&mut self, node_id: NodeID, destination: &Path) -> Result<()> {
+            let parent_id = self.nodes[node_id].parent;
+            let parent = &mut self.nodes[parent_id];
+
+            // remove the node from its parent temporarily so that the search never returns this
+            // link and that way any link will find means an error.
+            // if an error does happen then we re-add this node to its parent to keep the data
+            // consistent.
+            match &mut parent.kind {
+                NodeKind::Link(_) => unreachable!(),
+                NodeKind::Directory(children) => children.remove(&node_id),
+            };
+
+            let search_result = self.search(destination);
+            // handle the error cases
+            match search_result {
+                NodeSearchResult::Found(found_id) => {
+                    assert!(found_id != node_id);
+                    self.directory_add_child(parent_id, node_id);
+                    return Err(anyhow::anyhow!("link already exists at that path"));
+                }
+                NodeSearchResult::NotFound(ancestor_id) => {
+                    let ancestor = &self.nodes[ancestor_id];
+                    match &ancestor.kind {
+                        NodeKind::Link(_) => {
+                            self.directory_add_child(parent_id, node_id);
+                            return Err(anyhow::anyhow!("ancestor path is already linked"));
+                        }
+                        NodeKind::Directory(_) => {}
+                    }
+                }
+            };
+
+            let destination_parent = path_parent_or_empty(destination);
+            let new_parent_id = self.directory_get_or_create(destination_parent, node_id);
+            if new_parent_id != parent_id {
+                self.nodes[node_id].parent = new_parent_id;
+
+                // we have to re-add and call the remove function because it could lead to the removal
+                // of several directories if they become empty after this remove.
+                self.directory_add_child(parent_id, node_id);
+                self.directory_remove_child(parent_id, node_id);
+            }
+
+            // unwrap: destination is a verified link path so it has atleast 1 component
+            let comp = destination.file_name().unwrap();
+            let node = &mut self.nodes[node_id];
+            if node.comp != comp {
+                node.comp = comp.to_owned();
+            }
+
+            Ok(())
+        }
+
+        pub fn link_search(&self, path: &Path) -> SearchResult {
+            match self.search(path) {
+                NodeSearchResult::Found(node_id) => match &self.nodes[node_id].kind {
+                    NodeKind::Link(link_id) => SearchResult::Found(*link_id),
+                    NodeKind::Directory(_) => SearchResult::NotFound,
+                },
+                NodeSearchResult::NotFound(node_id) => match &self.nodes[node_id].kind {
+                    NodeKind::Link(link_id) => SearchResult::Ancestor(*link_id),
+                    NodeKind::Directory(_) => SearchResult::NotFound,
+                },
+            }
+        }
+
+        /// remove a node of kind [`NodeKind::Link`].
+        pub fn link_remove(&mut self, node_id: NodeID) {
+            let node = &self.nodes[node_id];
+            assert!(std::matches!(node.kind, NodeKind::Link(_)));
+            let parent_id = node.parent;
+            self.nodes.remove(node_id);
+            self.directory_remove_child(parent_id, node_id);
+        }
+
+        pub fn links_under(&self, path: &Path) -> impl Iterator<Item = LinkID> + '_ {
+            let links = match self.search(path) {
+                NodeSearchResult::Found(node_id) => {
+                    let node = &self.nodes[node_id];
+                    match &node.kind {
+                        NodeKind::Link(link_id) => vec![*link_id],
+                        NodeKind::Directory(children) => {
+                            let mut links = Vec::new();
+                            let mut node_ids = Vec::from_iter(children.iter().copied());
+                            while let Some(child_id) = node_ids.pop() {
+                                let child = &self.nodes[child_id];
+                                match &child.kind {
+                                    NodeKind::Link(link_id) => links.push(*link_id),
+                                    NodeKind::Directory(extra_children) => {
+                                        node_ids.extend(extra_children.iter().copied())
+                                    }
+                                }
+                            }
+                            links
+                        }
+                    }
+                }
+                NodeSearchResult::NotFound(_) => vec![],
+            };
+            links.into_iter()
+        }
+
+        pub fn has_links_under(&self, path: &Path) -> bool {
+            // it does not matter what type of node is found. if a directory exists then there
+            // must be atleast one link under it.
+            match self.search(path) {
+                NodeSearchResult::Found(_) => true,
+                NodeSearchResult::NotFound(_) => false,
+            }
+        }
+
+        pub fn read_dir(&self, path: &Path) -> Result<impl Iterator<Item = DirNode> + '_> {
+            match self.search(path) {
+                NodeSearchResult::Found(node_id) => match &self.nodes[node_id].kind {
+                    NodeKind::Link(_) => Err(anyhow::anyhow!("read dir called on a link")),
+                    NodeKind::Directory(children) => Ok(children.iter().map(|child_id| {
+                        let child = &self.nodes[*child_id];
+                        match &child.kind {
+                            NodeKind::Link(link_id) => DirNode::Link(*link_id),
+                            NodeKind::Directory(_) => {
+                                DirNode::Directory(self.build_path(*child_id))
+                            }
+                        }
+                    })),
+                },
+                NodeSearchResult::NotFound(_) => Err(anyhow::anyhow!("directory not found")),
+            }
+        }
+
+        pub fn build_path(&self, node_id: NodeID) -> PathBuf {
+            fn recursive_helper(nodes: &SlotMap<NodeID, Node>, nid: NodeID, pbuf: &mut PathBuf) {
+                if nid.is_null() {
+                    return;
+                }
+                let parent_id = nodes[nid].parent;
+                recursive_helper(nodes, parent_id, pbuf);
+                pbuf.push(&nodes[nid].comp);
+            }
+
+            let mut node_path = PathBuf::default();
+            recursive_helper(&self.nodes, node_id, &mut node_path);
+            node_path
+        }
+
+        fn search(&self, path: &Path) -> NodeSearchResult {
+            debug_assert!(path_verify(path).is_ok());
+
+            let mut curr_node_id = self.root;
+            let mut comp_iter = path_iter_comps(path).peekable();
+            while let Some(comp) = comp_iter.next() {
+                if let Some(child_id) = self.directory_search_children(curr_node_id, comp) {
+                    let child = &self.nodes[child_id];
+                    match &child.kind {
+                        NodeKind::Link(_) => {
+                            if comp_iter.peek().is_some() {
+                                return NodeSearchResult::NotFound(child_id);
+                            } else {
+                                return NodeSearchResult::Found(child_id);
+                            }
+                        }
+                        NodeKind::Directory(_) => curr_node_id = child_id,
+                    }
+                } else {
+                    return NodeSearchResult::NotFound(curr_node_id);
+                }
+            }
+            NodeSearchResult::Found(curr_node_id)
+        }
+
+        // creates directories all the way up to and including path.
+        // there cannot be any links up to `path`.
+        fn directory_get_or_create(&mut self, path: &Path, initial_child: NodeID) -> NodeID {
+            // TODO: this could be replaced if the search function also returned the depth of the
+            // node and we skip those components and just start creating directories up to the
+            // path.
+            let mut curr_node_id = self.root;
+            for comp in path_iter_comps(path) {
+                if let Some(child_id) = self.directory_search_children(curr_node_id, comp) {
+                    debug_assert!(std::matches!(
+                        self.nodes[child_id].kind,
+                        NodeKind::Directory(_)
+                    ));
+                    curr_node_id = child_id;
+                } else {
+                    let new_node_id = self.nodes.insert(Node {
+                        comp: comp.to_owned(),
+                        parent: curr_node_id,
+                        kind: NodeKind::Directory(Default::default()),
+                    });
+                    self.directory_add_child(curr_node_id, new_node_id);
+                    curr_node_id = new_node_id;
+                }
+            }
+            self.directory_add_child(curr_node_id, initial_child);
+            curr_node_id
+        }
+
+        fn directory_search_children(&self, node_id: NodeID, comp: &OsStr) -> Option<NodeID> {
+            let node = &self.nodes[node_id];
+            match &node.kind {
+                NodeKind::Link(_) => unreachable!(),
+                NodeKind::Directory(children) => {
+                    for &child_id in children {
+                        let child = &self.nodes[child_id];
+                        if child.comp == comp {
+                            return Some(child_id);
+                        }
+                    }
+                }
+            }
+            None
+        }
+
+        fn directory_add_child(&mut self, node_id: NodeID, child_id: NodeID) {
+            let node = &mut self.nodes[node_id];
+            match &mut node.kind {
+                NodeKind::Link(_) => unreachable!(),
+                NodeKind::Directory(children) => children.insert(child_id),
+            };
+        }
+
+        fn directory_remove_child(&mut self, node_id: NodeID, child_id: NodeID) {
+            let node = &mut self.nodes[node_id];
+            match &mut node.kind {
+                NodeKind::Link(_) => unreachable!(),
+                NodeKind::Directory(children) => {
+                    children.remove(&child_id);
+                    if children.is_empty() && !node.parent.is_null() {
+                        let parent_id = node.parent;
+                        self.directory_remove_child(parent_id, node_id);
+                    }
+                }
+            }
+        }
+    }
+
+    #[derive(Debug, Default, Clone)]
+    pub struct Depot {
+        links: SlotMap<LinkID, Link>,
+        origin: DepotTree,
+    }
+
+    impl Depot {
+        pub fn link_create(
+            &mut self,
+            origin: impl AsRef<Path>,
+            destination: impl AsRef<Path>,
+        ) -> Result<LinkID> {
+            let origin = origin.as_ref();
+            let destination = destination.as_ref();
+            path_verify_link(origin)?;
+            path_verify_link(destination)?;
+            self.link_create_unchecked(origin, destination)
+        }
+
+        pub fn link_remove(&mut self, link_id: LinkID) {
+            let node_id = self.links[link_id].origin_id;
+            self.links.remove(link_id);
+            self.origin.link_remove(node_id);
+        }
+
+        /// moves the link specified by `link_id` to the path at `destination`.
+        /// if the link is already at the destination nothing is done.
+        /// if the destination is another link that that link is removed.
+        /// if the destination is under another link then an error is returned.
+        /// `destination` will be the link's new origin.
+        pub fn link_move(&mut self, link_id: LinkID, destination: impl AsRef<Path>) -> Result<()> {
+            let destination = destination.as_ref();
+            path_verify_link(destination)?;
+            self.link_move_unchecked(link_id, destination)
+        }
+
+        pub fn link_search(&self, path: impl AsRef<Path>) -> Result<SearchResult> {
+            let path = path.as_ref();
+            path_verify(path)?;
+            Ok(self.link_search_unchecked(path))
+        }
+
+        pub fn link_find(&self, path: impl AsRef<Path>) -> Result<Option<LinkID>> {
+            let path = path.as_ref();
+            path_verify(path)?;
+            Ok(self.link_find_unchecked(path))
+        }
+
+        pub fn links_under(
+            &self,
+            path: impl AsRef<Path>,
+        ) -> Result<impl Iterator<Item = LinkID> + '_> {
+            let path = path.as_ref();
+            path_verify(path)?;
+            Ok(self.links_under_unchecked(path))
+        }
+
+        pub fn has_links_under(&self, path: impl AsRef<Path>) -> Result<bool> {
+            let path = path.as_ref();
+            path_verify(path)?;
+            Ok(self.has_links_under_unchecked(path))
+        }
+
+        pub fn link_view(&self, link_id: LinkID) -> LinkView {
+            LinkView {
+                link_id,
+                depot: self,
+            }
+        }
+
+        pub fn read_dir(
+            &self,
+            path: impl AsRef<Path>,
+        ) -> Result<impl Iterator<Item = DirNode> + '_> {
+            let path = path.as_ref();
+            path_verify(path)?;
+            self.read_dir_unchecked(path)
+        }
+
+        fn link_create_unchecked(&mut self, origin: &Path, destination: &Path) -> Result<LinkID> {
+            let node_id = self.origin.link_create(origin, Default::default())?;
+            let link_id = self.links.insert(Link {
+                origin: origin.to_owned(),
+                destination: destination.to_owned(),
+                origin_id: node_id,
+            });
+            self.origin.link_update_id(node_id, link_id);
+            Ok(link_id)
+        }
+
+        fn link_move_unchecked(&mut self, link_id: LinkID, destination: &Path) -> Result<()> {
+            let link = &self.links[link_id];
+            if link.origin == destination {
+                return Ok(());
+            }
+            let node_id = link.origin_id;
+            self.origin.link_move(node_id, destination)?;
+            self.links[link_id].origin = destination.to_owned();
+            Ok(())
+        }
+
+        fn link_search_unchecked(&self, path: &Path) -> SearchResult {
+            self.origin.link_search(path)
+        }
+
+        fn link_find_unchecked(&self, path: &Path) -> Option<LinkID> {
+            match self.link_search_unchecked(path) {
+                SearchResult::Found(link_id) => Some(link_id),
+                _ => None,
+            }
+        }
+
+        fn links_under_unchecked(&self, path: &Path) -> impl Iterator<Item = LinkID> + '_ {
+            self.origin.links_under(path)
+        }
+
+        fn has_links_under_unchecked(&self, path: &Path) -> bool {
+            self.origin.has_links_under(path)
+        }
+
+        fn read_dir_unchecked(&self, path: &Path) -> Result<impl Iterator<Item = DirNode> + '_> {
+            self.origin.read_dir(path)
+        }
+    }
+
+    /// a verified link path is a path that:
+    /// + is not empty
+    /// + is relative
+    /// + does not contain Prefix/RootDir/ParentDir
+    fn path_verify_link(path: &Path) -> Result<()> {
+        // make sure the path is not empty
+        if path.components().next().is_none() {
+            return Err(DepotError::InvalidLinkPath.into());
+        }
+        path_verify(path).map_err(|_| DepotError::InvalidLinkPath.into())
+    }
+
+    /// a verified path is a path that:
+    /// + is not empty
+    /// + is relative
+    /// + does not contain Prefix/RootDir/ParentDir
+    fn path_verify(path: &Path) -> Result<()> {
+        // make sure the path is relative
+        // make sure the path does not contain '.' or '..'
+        for component in path.components() {
+            match component {
+                std::path::Component::Prefix(_)
+                | std::path::Component::RootDir
+                | std::path::Component::CurDir
+                | std::path::Component::ParentDir => return Err(DepotError::InvalidPath.into()),
+                std::path::Component::Normal(_) => {}
+            }
+        }
+        Ok(())
+    }
+
+    fn path_parent_or_empty(path: &Path) -> &Path {
+        path.parent().unwrap_or(Path::new(""))
+    }
+
+    /// Iterate over the components of a path.
+    /// # Pre
+    /// The path can only have "Normal" components.
+    fn path_iter_comps(path: &Path) -> impl Iterator<Item = &OsStr> {
+        debug_assert!(path_verify(path).is_ok());
+        path.components().map(|component| match component {
+            std::path::Component::Normal(comp) => comp,
+            _ => unreachable!(),
+        })
+    }
+
+    mod disk {
+        use std::path::{Path, PathBuf};
+
+        use anyhow::Context;
+        use serde::{Deserialize, Serialize};
+
+        use super::Depot;
+
+        #[derive(Debug, Serialize, Deserialize)]
+        struct DiskLink {
+            origin: PathBuf,
+            destination: PathBuf,
+        }
+
+        #[derive(Debug, Serialize, Deserialize)]
+        struct DiskLinks {
+            links: Vec<DiskLink>,
+        }
+
+        pub fn read(path: &Path) -> anyhow::Result<Depot> {
+            let contents = std::fs::read_to_string(path).context("Failed to read depot file")?;
+            let disk_links = toml::from_str::<DiskLinks>(&contents)
+                .context("Failed to parse depot file")?
+                .links;
+            let mut depot = Depot::default();
+            for disk_link in disk_links {
+                depot
+                    .link_create(disk_link.origin, disk_link.destination)
+                    .context("Failed to build depot from file. File is in an invalid state")?;
+            }
+            Ok(depot)
+        }
+
+        pub fn write(path: &Path, depot: &Depot) -> anyhow::Result<()> {
+            let mut links = Vec::with_capacity(depot.links.len());
+            for (_, link) in depot.links.iter() {
+                links.push(DiskLink {
+                    origin: link.origin.clone(),
+                    destination: link.destination.clone(),
+                });
+            }
+            let contents = toml::to_string_pretty(&DiskLinks { links })
+                .context("Failed to serialize depot")?;
+            std::fs::write(path, contents).context("Failed to write depot to file")?;
+            Ok(())
+        }
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+
+        #[test]
+        fn test_depot_link_create() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("f1", "f1").unwrap();
+            let f2 = depot.link_create("f2", "f2").unwrap();
+            let f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let f4 = depot.link_create("d1/d2/f4", "d1/d2/d4").unwrap();
+
+            assert_eq!(depot.link_find("f1").unwrap(), Some(f1));
+            assert_eq!(depot.link_find("f2").unwrap(), Some(f2));
+            assert_eq!(depot.link_find("d1/f3").unwrap(), Some(f3));
+            assert_eq!(depot.link_find("d1/d2/f4").unwrap(), Some(f4));
+
+            depot.link_create("f2", "").unwrap_err();
+            depot.link_create("", "d4").unwrap_err();
+            depot.link_create("f1/f3", "f3").unwrap_err();
+        }
+
+        #[test]
+        fn test_depot_link_remove() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let _f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let d3 = depot.link_create("d3", "d3").unwrap();
+
+            depot.link_remove(f2);
+            assert_eq!(depot.link_find("d1/f1").unwrap(), Some(f1));
+            assert_eq!(depot.link_find("d1/f2").unwrap(), None);
+            depot.link_remove(f4);
+            assert_eq!(depot.link_find("d1/d2/f4").unwrap(), None);
+            depot.link_remove(d3);
+            assert_eq!(depot.link_find("d3").unwrap(), None);
+        }
+
+        #[test]
+        fn test_depot_link_move() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let _f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+
+            depot.link_move(f1, "").unwrap_err();
+            depot.link_move(f1, "d1/f2/f1").unwrap_err();
+            depot.link_move(f1, "d1/f2").unwrap_err();
+
+            depot.link_move(f1, "f1").unwrap();
+            assert_eq!(depot.link_view(f1).origin(), Path::new("f1"));
+            depot.link_move(f1, "f2").unwrap();
+            assert_eq!(depot.link_view(f1).origin(), Path::new("f2"));
+            assert_eq!(depot.link_find("f2").unwrap(), Some(f1));
+        }
+
+        #[test]
+        fn test_depot_link_search() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let _f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let _f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let _f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let _d3 = depot.link_create("d3", "d3").unwrap();
+
+            assert_eq!(depot.link_search("d1/f1").unwrap(), SearchResult::Found(f1));
+            assert_eq!(
+                depot.link_search("d1/f1/f5").unwrap(),
+                SearchResult::Ancestor(f1)
+            );
+            assert_eq!(depot.link_search("d1").unwrap(), SearchResult::NotFound);
+            assert_eq!(
+                depot.link_search("d1/d2/f5").unwrap(),
+                SearchResult::NotFound
+            );
+        }
+
+        #[test]
+        fn test_depot_link_find() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let _f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let d3 = depot.link_create("d3", "d3").unwrap();
+
+            assert_eq!(depot.link_find("d1/f1").unwrap(), Some(f1));
+            assert_eq!(depot.link_find("d1/f3").unwrap(), Some(f3));
+            assert_eq!(depot.link_find("d1/d2/f4").unwrap(), Some(f4));
+            assert_eq!(depot.link_find("d3").unwrap(), Some(d3));
+
+            assert_eq!(depot.link_find("d5").unwrap(), None);
+            assert_eq!(depot.link_find("d3/d5").unwrap(), None);
+            assert_eq!(depot.link_find("d1/d2/f5").unwrap(), None);
+        }
+
+        #[test]
+        fn test_depot_links_under() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let d3 = depot.link_create("d3", "d3").unwrap();
+
+            let under_f1 = depot.links_under("d1/f1").unwrap().collect::<Vec<_>>();
+            assert_eq!(under_f1, vec![f1]);
+
+            let under_d1 = depot.links_under("d1").unwrap().collect::<Vec<_>>();
+            let expected_under_d1 = vec![f1, f2, f3, f4];
+            assert!(
+                under_d1.len() == expected_under_d1.len()
+                    && expected_under_d1.iter().all(|x| under_d1.contains(x))
+            );
+
+            let under_d2 = depot.links_under("d2").unwrap().collect::<Vec<_>>();
+            assert_eq!(under_d2, vec![]);
+
+            let under_d3 = depot.links_under("d3").unwrap().collect::<Vec<_>>();
+            assert_eq!(under_d3, vec![d3]);
+
+            let under_root = depot.links_under("").unwrap().collect::<Vec<_>>();
+            let expected_under_root = vec![f1, f2, f3, f4, d3];
+            assert!(
+                under_root.len() == expected_under_root.len()
+                    && expected_under_root.iter().all(|x| under_root.contains(x))
+            );
+        }
+
+        #[test]
+        fn test_depot_has_links_under() {
+            let mut depot = Depot::default();
+            let _f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let _f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let _f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let _f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let _d3 = depot.link_create("d3", "d3").unwrap();
+
+            assert!(depot.has_links_under("").unwrap());
+            assert!(depot.has_links_under("d1").unwrap());
+            assert!(depot.has_links_under("d3").unwrap());
+            assert!(depot.has_links_under("d1/f1").unwrap());
+            assert!(depot.has_links_under("d1/d2").unwrap());
+            assert!(depot.has_links_under("d1/d2/f4").unwrap());
+
+            assert!(!depot.has_links_under("d2").unwrap());
+            assert!(!depot.has_links_under("d4").unwrap());
+            assert!(!depot.has_links_under("d1/d2/f4/f5").unwrap());
+        }
+
+        #[test]
+        fn test_depot_read_dir() {
+            let mut depot = Depot::default();
+            let f1 = depot.link_create("d1/f1", "d1/f1").unwrap();
+            let f2 = depot.link_create("d1/f2", "d1/f2").unwrap();
+            let f3 = depot.link_create("d1/f3", "d1/f3").unwrap();
+            let _f4 = depot.link_create("d1/d2/f4", "d2/f4").unwrap();
+            let _d3 = depot.link_create("d3", "d3").unwrap();
+
+            let read_dir = depot.read_dir("d1").unwrap().collect::<Vec<_>>();
+            let expected_read_dir = vec![
+                DirNode::Link(f1),
+                DirNode::Link(f2),
+                DirNode::Link(f3),
+                DirNode::Directory(PathBuf::from("d1/d2")),
+            ];
+            assert!(
+                read_dir.len() == expected_read_dir.len()
+                    && expected_read_dir.iter().all(|x| read_dir.contains(x))
+            );
+        }
+
+        #[test]
+        fn test_path_verify() {
+            path_verify(Path::new("")).unwrap();
+            path_verify(Path::new("f1")).unwrap();
+            path_verify(Path::new("d1/f1")).unwrap();
+            path_verify(Path::new("d1/f1.txt")).unwrap();
+            path_verify(Path::new("d1/./f1.txt")).unwrap();
+
+            path_verify(Path::new("/")).unwrap_err();
+            path_verify(Path::new("./f1")).unwrap_err();
+            path_verify(Path::new("/d1/f1")).unwrap_err();
+            path_verify(Path::new("d1/../f1.txt")).unwrap_err();
+            path_verify(Path::new("/d1/../f1.txt")).unwrap_err();
+        }
+
+        #[test]
+        fn test_path_verify_link() {
+            path_verify_link(Path::new("f1")).unwrap();
+            path_verify_link(Path::new("d1/f1")).unwrap();
+            path_verify_link(Path::new("d1/f1.txt")).unwrap();
+            path_verify_link(Path::new("d1/./f1.txt")).unwrap();
+
+            path_verify_link(Path::new("")).unwrap_err();
+            path_verify_link(Path::new("/")).unwrap_err();
+            path_verify_link(Path::new("./f1")).unwrap_err();
+            path_verify_link(Path::new("/d1/f1")).unwrap_err();
+            path_verify_link(Path::new("d1/../f1.txt")).unwrap_err();
+            path_verify_link(Path::new("/d1/../f1.txt")).unwrap_err();
+        }
+
+        #[test]
+        fn test_path_iter_comps() {
+            let path = Path::new("comp1/comp2/./comp3/file.txt");
+            let mut iter = path_iter_comps(path);
+            assert_eq!(iter.next(), Some(OsStr::new("comp1")));
+            assert_eq!(iter.next(), Some(OsStr::new("comp2")));
+            assert_eq!(iter.next(), Some(OsStr::new("comp3")));
+            assert_eq!(iter.next(), Some(OsStr::new("file.txt")));
+            assert_eq!(iter.next(), None);
+        }
+    }
+}
+
+pub mod depot2 {
     use std::{
         collections::HashSet,
         ffi::{OsStr, OsString},
@@ -933,19 +1773,16 @@ pub mod dotup {
             }
         }
 
-        pub fn unlink(&mut self, paths: impl Iterator<Item = impl AsRef<Path>>) {
+        pub fn unlink(&mut self, paths: impl Iterator<Item = impl AsRef<Path>>, uninstall: bool) {
             for origin in paths {
                 let unlink_result: anyhow::Result<()> = try {
                     let origin = self.prepare_relative_path(origin.as_ref())?;
-                    let search_results = self.depot.link_search(&origin)?;
-                    match search_results {
-                        depot::SearchResult::Found(link_id) => {
-                            self.depot.link_remove(link_id);
-                            println!("removed link {}", origin.display());
-                        }
-                        depot::SearchResult::Ancestor(_) | depot::SearchResult::NotFound => {
-                            println!("{} is not linked", origin.display())
+                    let links_under: Vec<_> = self.depot.links_under(&origin)?.collect();
+                    for link_id in links_under {
+                        if uninstall && self.symlink_is_installed_by_link_id(link_id)? {
+                            self.symlink_uninstall_by_link_id(link_id)?;
                         }
+                        self.depot.link_remove(link_id);
                     }
                 };
                 match unlink_result {
@@ -1149,7 +1986,7 @@ pub mod dotup {
                 } else if is_installed {
                     Color::Green
                 } else {
-                    Color::Cyan
+                    Color::RGB(255, 127, 0)
                 }
             }
 
@@ -1301,6 +2138,11 @@ pub mod dotup {
             Ok(())
         }
 
+        fn symlink_uninstall_by_link_id(&self, link_id: LinkID) -> anyhow::Result<()> {
+            let canonical_pair = self.canonical_pair_from_link_id(link_id);
+            self.symlink_uninstall(&canonical_pair.origin, &canonical_pair.destination)
+        }
+
         fn canonical_pair_from_link_id(&self, link_id: LinkID) -> CanonicalPair {
             let link_view = self.depot.link_view(link_id);
             let relative_origin = link_view.origin();
@@ -1336,7 +2178,10 @@ pub mod dotup {
 }
 
 mod utils {
-    use std::path::{Component, Path, PathBuf};
+    use std::{
+        collections::VecDeque,
+        path::{Component, Path, PathBuf},
+    };
 
     use crate::{
         dotup::{self, Dotup},
@@ -1345,6 +2190,29 @@ mod utils {
 
     pub const DEFAULT_DEPOT_FILE_NAME: &str = ".depot";
 
+    /// Returns a list of canonical paths to all the files in `dir`. This includes files in
+    /// subdirectories.
+    /// Fails if dir isnt a directory or if there is some other io error.
+    pub fn collect_files_in_dir_recursive(dir: impl Into<PathBuf>) -> anyhow::Result<Vec<PathBuf>> {
+        let mut paths = Vec::new();
+        let mut dirs = VecDeque::new();
+        dirs.push_back(dir.into());
+
+        while let Some(dir) = dirs.pop_front() {
+            for entry in std::fs::read_dir(dir)? {
+                let entry = entry?;
+                let filetype = entry.file_type()?;
+                if filetype.is_dir() {
+                    dirs.push_back(entry.path());
+                } else {
+                    paths.push(entry.path());
+                }
+            }
+        }
+
+        Ok(paths)
+    }
+
     pub fn collect_paths_in_dir(dir: impl AsRef<Path>) -> anyhow::Result<Vec<PathBuf>> {
         Ok(std::fs::read_dir(dir)?
             .filter_map(|e| e.ok())
@@ -1522,6 +2390,7 @@ fn main() -> anyhow::Result<()> {
         2 => "debug",
         _ => "trace",
     };
+    let log_level = "trace";
 
     Logger::try_with_env_or_str(log_level)?
         .format(flexi_logger::colored_default_format)
@@ -1565,31 +2434,48 @@ fn command_init(_global_flags: Flags, args: InitArgs) -> anyhow::Result<()> {
 
 #[derive(Parser, Debug)]
 struct LinkArgs {
+    #[clap(long)]
+    directory: bool,
+
     origin: PathBuf,
+
     destination: PathBuf,
 }
 
 fn command_link(global_flags: Flags, args: LinkArgs) -> anyhow::Result<()> {
     let mut dotup = utils::read_dotup(&global_flags)?;
-    dotup.link(args.origin, args.destination);
+    let origins = if args.directory {
+        vec![args.origin]
+    } else {
+        utils::collect_files_in_dir_recursive(args.origin)?
+    };
+    for origin in origins {
+        dotup.link(origin, &args.destination);
+    }
     utils::write_dotup(&dotup)?;
     Ok(())
 }
 
 #[derive(Parser, Debug)]
 struct UnlinkArgs {
+    #[clap(long)]
+    uninstall: bool,
+
     paths: Vec<PathBuf>,
 }
 
 fn command_unlink(global_flags: Flags, args: UnlinkArgs) -> anyhow::Result<()> {
     let mut dotup = utils::read_dotup(&global_flags)?;
-    dotup.unlink(args.paths.into_iter());
+    dotup.unlink(args.paths.into_iter(), args.uninstall);
     utils::write_dotup(&dotup)?;
     Ok(())
 }
 
 #[derive(Parser, Debug)]
 struct InstallArgs {
+    #[clap(long)]
+    directory: bool,
+
     paths: Vec<PathBuf>,
 }