1 files changed, 48 insertions, 0 deletions
diff --git a/src/cmd/folders.rs b/src/cmd/folders.rs
new file mode 100644
index 0000000..7bf93f1
--- /dev/null
+++ b/src/cmd/folders.rs
@@ -0,0 +1,48 @@
+use std::collections::BTreeSet;
+use std::ffi::{OsStr, OsString};
+use std::path::Path;
+
+use lazy_static::lazy_static;
+use maildir::Maildir;
+
+use crate::error::Result;
+
+lazy_static! {
+    static ref REQUIRED_MAILDIR_DIRS: BTreeSet<OsString> = [
+        OsString::from("cur"),
+        "new".into(),
+        "tmp".into(),
+        "maildirfolder".into(),
+    ]
+    .into();
+}
+
+fn is_mailsubdir(p: &Path) -> bool {
+    p.is_dir()
+        && p.file_name()
+            .map_or(false, |fname| fname.to_string_lossy().starts_with('.'))
+        && p.read_dir()
+            .map(|dir| {
+                dir.filter_map(|child| {
+                    child
+                        .ok()
+                        .and_then(|dir_entry| dir_entry.path().file_name().map(OsStr::to_owned))
+                })
+                .collect::<BTreeSet<_>>()
+                .is_superset(&REQUIRED_MAILDIR_DIRS)
+            })
+            .unwrap_or_default()
+}
+
+pub fn folders(md: &Maildir) -> Result<Vec<String>> {
+    let root_path = md.path();
+
+    let subdirs = root_path
+        .read_dir()?
+        .filter_map(|d| d.ok())
+        .filter(|d| is_mailsubdir(&d.path()))
+        .filter_map(|d| Some(d.path().file_name()?.to_string_lossy()[1..].to_owned()))
+        .collect();
+
+    Ok(subdirs)
+}