1 files changed, 62 insertions, 0 deletions
diff --git a/src/completion.rs b/src/completion.rs
index 3e2565b..c7a183f 100644
--- a/src/completion.rs
+++ b/src/completion.rs
@@ -1,3 +1,4 @@
+use crate::parse::{self, CompletionContext};
 use crate::{BString, Session};
 use std::collections::HashMap;
 use std::ffi::OsStr;
@@ -139,3 +140,64 @@ pub fn command_completion(session: Arc<Mutex<Session>>, prefix: BString) -> Vec<
 
     out
 }
+
+pub struct CompletionResult {
+    pub kind: parse::CompletionKind,
+    pub suggestions: Vec<Suggestion>,
+    pub shared_prefix: BString,
+}
+
+impl CompletionResult {
+    pub fn empty() -> Self {
+        CompletionResult {
+            kind: parse::CompletionKind::None,
+            suggestions: Vec::new(),
+            shared_prefix: BString::new(),
+        }
+    }
+}
+
+pub fn completion(session: Arc<Mutex<Session>>, cmd: &[u8]) -> CompletionResult {
+    let comp = parse::completion_context(
+        &cmd,
+        &mut crate::run::Executor::new_for_completion(session.clone()),
+    );
+
+    let mut suggestions = match comp.kind {
+        parse::CompletionKind::Command => command_completion(session.clone(), comp.partial),
+        parse::CompletionKind::Argument => path_completion(comp.partial),
+        parse::CompletionKind::Variable => variable_completion(session.clone(), comp.partial),
+        parse::CompletionKind::None => return CompletionResult::empty(),
+    };
+
+    suggestions.sort_by(|x, y| x.delta.cmp(&y.delta));
+    suggestions.dedup_by(|x, y| x.delta == y.delta);
+
+    if suggestions.is_empty() {
+        return CompletionResult {
+            kind: comp.kind,
+            ..CompletionResult::empty()
+        };
+    }
+
+    // find longest shared prefix
+    let mut shared_prefix = &suggestions[0].delta[..];
+    for s in suggestions.iter() {
+        let mut new = &shared_prefix[..0];
+        for i in 0..shared_prefix.len().min(s.delta.len()) {
+            if shared_prefix[i] != s.delta[i] {
+                break;
+            } else {
+                new = &s.delta[..=i];
+            }
+        }
+        shared_prefix = new;
+    }
+    let shared_prefix = shared_prefix.to_vec();
+
+    CompletionResult {
+        kind: comp.kind,
+        suggestions,
+        shared_prefix,
+    }
+}