1 files changed, 74 insertions, 0 deletions
diff --git a/src/repository/fs/path.rs b/src/repository/fs/path.rs
new file mode 100644
index 0000000..b7fb407
--- /dev/null
+++ b/src/repository/fs/path.rs
@@ -0,0 +1,74 @@
+//
+// Copyright (c) 2020-2021 science+computing ag and other contributors
+//
+// This program and the accompanying materials are made
+// available under the terms of the Eclipse Public License 2.0
+// which is available at https://www.eclipse.org/legal/epl-2.0/
+//
+// SPDX-License-Identifier: EPL-2.0
+//
+
+use std::collections::HashMap;
+use std::convert::TryFrom;
+use std::path::Component;
+use std::path::Path;
+use std::path::PathBuf;
+
+use anyhow::anyhow;
+use anyhow::Result;
+
+/// Helper type for filtering for pathes we need or dont need
+///
+/// We either have a directory, which has a name, or we have a pkg.toml file, which is of interest.
+/// All other files can be ignored and thus are not represented by this type.
+///
+/// The PathComponent::DirName(_) represents a _part_ of a Path. Something like
+///
+/// ```ignore
+///     let p = PathBuf::from("foo/bar/baz")
+///     p.components().map(PathComponent::DirName) // does not actually work because of types
+/// ```
+///
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum PathComponent {
+    PkgToml,
+    DirName(String),
+}
+
+impl TryFrom<&std::path::Component<'_>> for PathComponent {
+    type Error = anyhow::Error;
+
+    fn try_from(c: &std::path::Component) -> Result<Self> {
+        match *c {
+            Component::Prefix(_) => anyhow::bail!("Unexpected path component: Prefix"),
+            Component::RootDir => anyhow::bail!("Unexpected path component: RootDir"),
+            Component::CurDir => anyhow::bail!("Unexpected path component: CurDir"),
+            Component::ParentDir => anyhow::bail!("Unexpected path component: ParentDir"),
+            Component::Normal(filename) => {
+                let filename = filename.to_str().ok_or_else(|| anyhow!("UTF8-error"))?;
+                if filename == "pkg.toml" {
+                    Ok(PathComponent::PkgToml)
+                } else {
+                    Ok(PathComponent::DirName(filename.to_string()))
+                }
+            },
+        }
+    }
+}
+
+impl PathComponent {
+    /// Helper fn whether this PathComponent is a PathComponent::PkgToml
+    pub fn is_pkg_toml(&self) -> bool {
+        std::matches!(self, PathComponent::PkgToml)
+    }
+
+    /// Helper fn to get the directory name of this PathComponent if it is a PathComponent::DirName
+    /// or None if it is not.
+    pub fn dir_name(&self) -> Option<&str> {
+        match self {
+            PathComponent::PkgToml => None,
+            PathComponent::DirName(dn) => Some(dn)
+        }
+    }
+}
+