octopus: supergit: implement initial tree history mechanism

4 files changed, 191 insertions, 12 deletions

diff --git a/apps/servers/octopus/supergit/src/commit.rs b/apps/servers/octopus/supergit/src/commit.rs
index 58b57ce22f73..b88e01331d95 100644
--- a/apps/servers/octopus/supergit/src/commit.rs
+++ b/apps/servers/octopus/supergit/src/commit.rs
@@ -1,6 +1,9 @@
 use crate::{files::FileTree, Diff, HashId};
 use git2::Repository;
-use std::sync::Arc;
+use std::{
+    fmt::{self, Debug, Formatter},
+    sync::Arc,
+};
 
 /// Represent a commit on a repository
 ///
@@ -12,6 +15,12 @@ pub struct Commit {
     repo: Arc<Repository>,
 }
 
+impl Debug for Commit {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}", self.id)
+    }
+}
+
 impl Commit {
     /// Create a commit object and check if it exists in the repo
     pub(crate) fn new(r: &Arc<Repository>, id: HashId) -> Option<Self> {
diff --git a/apps/servers/octopus/supergit/src/files/explorer.rs b/apps/servers/octopus/supergit/src/files/explorer.rs
index 89ad461b8ade..13433dd3cf86 100644
--- a/apps/servers/octopus/supergit/src/files/explorer.rs
+++ b/apps/servers/octopus/supergit/src/files/explorer.rs
@@ -1,5 +1,7 @@
 
+/// A dynamic tree explorer
 ///
+/// 
 pub struct Explorer {}
 
 ///
diff --git a/apps/servers/octopus/supergit/src/files/tree.rs b/apps/servers/octopus/supergit/src/files/tree.rs
index 5f4fb6671aa5..4903bad58f6f 100644
--- a/apps/servers/octopus/supergit/src/files/tree.rs
+++ b/apps/servers/octopus/supergit/src/files/tree.rs
@@ -1,7 +1,7 @@
 //! Low-level abstraction over finding refs inside a commit tree
 
-use super::tree_utils as utils;
-use crate::HashId;
+use super::tree_utils::{self as utils, PairIter};
+use crate::{branch::BranchIter, files::Yield, Commit, HashId};
 use git2::{ObjectType, Repository, TreeWalkMode, TreeWalkResult};
 use std::sync::Arc;
 
@@ -25,6 +25,80 @@ impl FileTree {
         Self { repo, c }
     }
 
+    /// Get a FileTree for a new commit
+    fn checkout(&self, c: HashId) -> Self {
+        Self::new(Arc::clone(&self.repo), c)
+    }
+
+    /// Get the history of a path with a branch iterator
+    pub fn base_history(&self, iter: BranchIter, path: &str) -> Option<Vec<Commit>> {
+        let mut iter = iter.peekable();
+
+        let entry = self.resolve(path)?;
+        let trgid = entry.id();
+
+        let mut commits = vec![];
+
+        // Iterate over the branch in commit pairs
+        while let (Some(a), b) = iter.next_pair() {
+            dbg!(&a.commit());
+            let ta = self.checkout(a.commit().id.clone());
+            let te_a = dbg!(ta.resolve(dbg!(path)));
+
+            let b = match b {
+                Some(b) => b,
+                None if te_a.is_some() => {
+                    // If b doesn't exist, but the path exists in a,
+                    // then it is safe to assume that a introduces the
+                    // path
+                    commits.push(a.commit().clone());
+                    break;
+                }
+                None => break,
+            };
+
+            let tb = self.checkout(b.commit().id.clone());
+            let te_b = match ta.resolve(path) {
+                Some(b) => b,
+                None => continue,
+            };
+
+            let te_a = match te_a {
+                Some(a) => a,
+                None => continue,
+            };
+
+            // If the two tree nodes are not equal, add the commit to
+            // the list.  This means that the `a` commit changed
+            // something in the path.
+            if dbg!(te_a != te_b) {
+                commits.push(a.commit().clone());
+            }
+        }
+
+        Some(commits)
+    }
+
+    /// Enumerate a non-leaf tree entry
+    pub fn enumerate(&self, path: &str) -> Option<Vec<TreeEntry>> {
+        let tree = utils::open_tree(&self.repo, &self.c)?;
+        let target = utils::path_split(path);
+
+        let mut entries = vec![];
+        tree.walk(TreeWalkMode::PreOrder, |p, e| {
+            let path = utils::path_split(p);
+            if path == target {
+                entries.push(TreeEntry::new(p, &e));
+                TreeWalkResult::Ok
+            } else {
+                TreeWalkResult::Skip
+            }
+        })
+        .ok()?;
+
+        Some(entries)
+    }
+
     /// Resolve a path inside this file tree
     ///
     /// Will return `None` if there is no tree for the selected
@@ -38,14 +112,15 @@ impl FileTree {
 
         // Walk over tree and swallor errors (which we use to
         // terminace traversal to speed up indexing time)
-        let _ = tree.walk(TreeWalkMode::PreOrder, |p, e| {
+        tree.walk(TreeWalkMode::PreOrder, |p, e| {
             if utils::path_cmp(&target, p, e.name().unwrap()) {
                 entry = Some(TreeEntry::new(p, &e));
                 TreeWalkResult::Ok
             } else {
                 TreeWalkResult::Skip
             }
-        });
+        })
+        .ok()?;
 
         // Return whatever the entry is now
         entry
@@ -57,10 +132,12 @@ impl FileTree {
 /// This type is lazily loaded, and can represent either a Blob or a
 /// Directory.  You can resolve its value by calling
 /// [`resolve()`](Self::resolve)
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct TreeEntry {
     tt: EntryType,
     id: HashId,
     path: String,
+    name: Option<String>,
 }
 
 impl TreeEntry {
@@ -72,15 +149,28 @@ impl TreeEntry {
         };
         let id = entry.id().into();
         let path = path.into();
+        let name = entry.name().map(|s| s.into());
+
+        Self { tt, id, path, name }
+    }
 
-        Self { tt, id, path }
+    pub fn id(&self) -> HashId {
+        self.id.clone()
+    }
+
+    /// Get a reference to the name of this TreeEntry
+    pub fn name(&self) -> Option<&String> {
+        self.name.as_ref()
     }
 
     /// Resolve this type to a [`Yield`]()
-    pub fn resolve(&self) {}
+    pub fn resolve(&self) -> Yield {
+        todo!()
+    }
 }
 
 /// Type of a TreeEntry
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum EntryType {
     /// A file that can be loaded
     File,
@@ -89,7 +179,7 @@ pub enum EntryType {
 }
 
 #[test]
-fn index_tree() {
+fn s_resolve() {
     let path = env!("CARGO_MANIFEST_DIR").to_owned() + "/test-repo";
     use crate::Repository as Repo;
 
@@ -100,5 +190,48 @@ fn index_tree() {
     let h = b.head();
 
     let t = h.tree();
-    t.resolve("README".into()).unwrap();
+    t.resolve("README").unwrap();
+}
+
+#[test]
+fn s_enumerate() {
+    let path = env!("CARGO_MANIFEST_DIR").to_owned() + "/test-repo";
+    use crate::Repository as Repo;
+
+    eprintln!("Path: `{}`", path);
+
+    let r = Repo::open(&path).unwrap();
+    let b = r.branch("master".into()).unwrap();
+    let h = b.head();
+
+    let t = h.tree();
+    let entries = t.enumerate("").unwrap();
+
+    assert_eq!(
+        entries
+            .iter()
+            .filter_map(|e| e.name().map(|s| s.as_str()))
+            .collect::<Vec<_>>(),
+        vec!["README", "test.rs"]
+    );
+}
+
+#[test]
+fn s_history() {
+    let path = env!("CARGO_MANIFEST_DIR").to_owned() + "/test-repo";
+    use crate::Repository as Repo;
+
+    eprintln!("Path: `{}`", path);
+
+    let r = Repo::open(&path).unwrap();
+    let b = r.branch("master".into()).unwrap();
+
+    let head = b.head();
+    let iter = b.get_all();
+
+    let tree = head.tree();
+    let history = tree.base_history(iter, "test.rs").unwrap();
+
+    dbg!(&history);
+    assert_eq!(history.len(), 1);
 }
diff --git a/apps/servers/octopus/supergit/src/files/tree_utils.rs b/apps/servers/octopus/supergit/src/files/tree_utils.rs
index 55a6c2e0ffab..f5cb94a4031a 100644
--- a/apps/servers/octopus/supergit/src/files/tree_utils.rs
+++ b/apps/servers/octopus/supergit/src/files/tree_utils.rs
@@ -2,7 +2,33 @@
 
 use crate::HashId;
 use git2::{Repository, Tree};
-use std::{path::PathBuf, sync::Arc};
+use std::{iter::Peekable, path::PathBuf, sync::Arc};
+
+pub(super) trait PairIter<I, K>
+where
+    I: Iterator<Item = K>,
+{
+    /// Step through
+    fn pairs<'i, F: FnMut(K, Option<&K>)>(&'i mut self, cb: F);
+
+    fn next_pair<'i>(&'i mut self) -> (Option<K>, Option<&K>);
+}
+
+impl<I, K> PairIter<I, K> for Peekable<I>
+where
+    I: Iterator<Item = K>,
+{
+    fn pairs<'i, F: FnMut(K, Option<&K>)>(&'i mut self, mut cb: F) {
+        // Iterate until a->None
+        while let (Some(a), b) = self.next_pair() {
+            cb(a, b);
+        }
+    }
+
+    fn next_pair<'i>(&'i mut self) -> (Option<K>, Option<&K>) {
+        (self.next(), self.peek())
+    }
+}
 
 /// Take a vector of path segments, and turn it into a valid offset path
 ///
@@ -32,8 +58,6 @@ pub(super) fn path_cmp(target: &Vec<&str>, path: &str, entry: &str) -> bool {
     let mut buf = path_split(path);
     buf.push(entry);
 
-    eprintln!("{:?}", buf);
-
     target == &buf
 }
 
@@ -59,3 +83,14 @@ fn nested_path() {
         String::from("foo/bar/baz")
     );
 }
+
+#[test]
+fn pair_iterator() {
+    // The pair iterator needs access to `peek()`
+    let mut i = vec![1, 2, 3, 4].into_iter().peekable();
+
+    assert_eq!(i.next_pair(), (Some(1), Some(&2)));
+    assert_eq!(i.next_pair(), (Some(2), Some(&3)));
+    assert_eq!(i.next_pair(), (Some(3), Some(&4)));
+    assert_eq!(i.next_pair(), (Some(4), None));
+}