added search functionality

src/app.rs

@@ -7,6 +7,8 @@ pub enum Mode {
     Normal,
     /// Active text entry mode for modifying values.
     Insert,
+    /// Active search mode for filtering keys.
+    Search,
 }
 
 /// The core application state, holding all configuration variables and UI status.
@@ -23,6 +25,8 @@ pub struct App {
     pub status_message: Option<String>,
     /// The active text input buffer for the selected variable.
     pub input: Input,
+    /// The current search query for filtering keys.
+    pub search_query: String,
 }
 
 impl App {
@@ -36,9 +40,24 @@ impl App {
             running: true,
             status_message: None,
             input: Input::new(initial_input),
+            search_query: String::new(),
         }
     }
 
+    /// Returns the indices of variables that match the search query.
+    pub fn matching_indices(&self) -> Vec<usize> {
+        if self.search_query.is_empty() {
+            return Vec::new();
+        }
+        let query = self.search_query.to_lowercase();
+        self.vars
+            .iter()
+            .enumerate()
+            .filter(|(_, v)| v.key.to_lowercase().contains(&query))
+            .map(|(i, _)| i)
+            .collect()
+    }
+
     /// Moves the selection to the next variable in the list, wrapping around if necessary.
     pub fn next(&mut self) {
         if !self.vars.is_empty() {
@@ -59,6 +78,43 @@ impl App {
         }
     }
 
+    /// Jumps to the next variable that matches the search query.
+    pub fn jump_next_match(&mut self) {
+        let indices = self.matching_indices();
+        if indices.is_empty() {
+            return;
+        }
+
+        let next_match = indices
+            .iter()
+            .find(|&&i| i > self.selected)
+            .or_else(|| indices.first());
+
+        if let Some(&index) = next_match {
+            self.selected = index;
+            self.sync_input_with_selected();
+        }
+    }
+
+    /// Jumps to the previous variable that matches the search query.
+    pub fn jump_previous_match(&mut self) {
+        let indices = self.matching_indices();
+        if indices.is_empty() {
+            return;
+        }
+
+        let prev_match = indices
+            .iter()
+            .rev()
+            .find(|&&i| i < self.selected)
+            .or_else(|| indices.last());
+
+        if let Some(&index) = prev_match {
+            self.selected = index;
+            self.sync_input_with_selected();
+        }
+    }
+
     /// Updates the input buffer to reflect the value of the currently selected variable.
     pub fn sync_input_with_selected(&mut self) {
         if let Some(var) = self.vars.get(self.selected) {