fix: restoring files from cached directory

src/main.rs

@@ -23,6 +23,13 @@ struct Input {
     key: CacheKey,
 }
 
+#[derive(Debug, PartialEq)]
+enum PathState {
+    Unused,
+    File,
+    Directory,
+}
+
 fn main() -> Result<()> {
     // parse inputs
     let Input { path, key } = Input::get();
@@ -45,34 +52,63 @@ fn main() -> Result<()> {
     let mut archive = Archive::new(in_uncomp);
     let mut paths = path
         .into_iter()
-        .map(|p| (p, true))
+        .map(|p| (p, PathState::Unused))
         .collect::<HashMap<_, _>>();
     let mut entry_path = PathBuf::new();
+    let mut directory_path = PathBuf::new();
     for entry in archive.entries().context("reading cache entries")? {
         let mut entry = entry.context("reading cache entry")?;
         entry_path.clear();
         entry_path.push(entry.path().context("reading entry path")?.as_ref());
-        let Some(needs_unpacking) = paths.get_mut(&entry_path) else {
+        if let Some(state) = paths.get_mut(&entry_path) {
+            // exact match on one of cached paths
+            match core::mem::replace(state, PathState::File) {
+                PathState::Unused => {
+                    entry.unpack(&entry_path).context("writing cache entry")?;
+                }
+                PathState::File => {
+                    println!(
+                        "warn: double entry in the archive: {}",
+                        entry_path.display()
+                    );
+                }
+                PathState::Directory => {
+                    println!(
+                        "WARN: found a regular file that was previously assumed to be a directory: {}",
+                        entry_path.display()
+                    );
+                }
+            }
+        }
+        if let Some(directory) = paths.keys().find(|p| entry_path.starts_with(p)) {
+            directory_path.clone_from(directory);
+            // file in a cached directory
+            let state = paths
+                .get_mut(&directory_path)
+                .expect("paths should contain a path that was just extracted as a key");
+            match core::mem::replace(state, PathState::Directory) {
+                PathState::Unused | PathState::Directory => {
+                    entry.unpack(&entry_path).context("writing cache entry")?;
+                }
+                PathState::File => {
+                    println!(
+                        "WARN: found a directory path that was previously assumed to be a regular file: {}",
+                        directory_path.display()
+                    );
+                }
+            }
+        } else {
             println!(
-                "warn: unknown entry in the archive: {}",
+                "warn: unmatched entry in the archive: {}",
                 entry_path.display()
             );
-            continue;
-        };
-        if !core::mem::replace(needs_unpacking, false) {
-            println!(
-                "warn: double entry in the archive: {}",
-                entry_path.display()
-            );
-            continue;
         }
-        entry.unpack(&entry_path).context("writing cache entry")?;
     }
 
-    for (path, needs_unpacking) in paths {
-        if needs_unpacking {
+    for (path, state) in paths {
+        if state == PathState::Unused {
             println!(
-                "warn: requested cached path was not found in the cache entry: {}",
+                "warn: cached path was not found in the cache: {}",
                 path.display(),
             );
         }