added documentation

src/app.rs

@@ -1,21 +1,32 @@
 use crate::format::EnvVar;
 use tui_input::Input;
 
+/// Represents the current operating mode of the application.
 pub enum Mode {
+    /// Standard navigation and command mode.
     Normal,
+    /// Active text entry mode for modifying values.
     Insert,
 }
 
+/// The core application state, holding all configuration variables and UI status.
 pub struct App {
+    /// The list of configuration variables being edited.
     pub vars: Vec<EnvVar>,
+    /// Index of the currently selected variable in the list.
     pub selected: usize,
+    /// The current interaction mode (Normal or Insert).
     pub mode: Mode,
+    /// Whether the main application loop should continue running.
     pub running: bool,
+    /// An optional message to display in the status bar (e.g., "Saved to .env").
     pub status_message: Option<String>,
+    /// The active text input buffer for the selected variable.
     pub input: Input,
 }
 
 impl App {
+    /// Initializes a new application instance with the provided variables.
     pub fn new(vars: Vec<EnvVar>) -> Self {
         let initial_input = vars.get(0).map(|v| v.value.clone()).unwrap_or_default();
         Self {
@@ -28,6 +39,7 @@ impl App {
         }
     }
 
+    /// Moves the selection to the next variable in the list, wrapping around if necessary.
     pub fn next(&mut self) {
         if !self.vars.is_empty() {
             self.selected = (self.selected + 1) % self.vars.len();
@@ -35,6 +47,7 @@ impl App {
         }
     }
 
+    /// Moves the selection to the previous variable in the list, wrapping around if necessary.
     pub fn previous(&mut self) {
         if !self.vars.is_empty() {
             if self.selected == 0 {
@@ -46,30 +59,29 @@ impl App {
         }
     }
 
+    /// 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) {
             self.input = Input::new(var.value.clone());
         }
     }
 
+    /// Commits the current text in the input buffer back to the selected variable's value.
     pub fn commit_input(&mut self) {
         if let Some(var) = self.vars.get_mut(self.selected) {
             var.value = self.input.value().to_string();
         }
     }
 
+    /// Transitions the application into Insert Mode.
     pub fn enter_insert(&mut self) {
         self.mode = Mode::Insert;
         self.status_message = None;
     }
 
+    /// Commits the current input and transitions the application into Normal Mode.
     pub fn enter_normal(&mut self) {
         self.commit_input();
         self.mode = Mode::Normal;
     }
-
-    #[allow(dead_code)]
-    pub fn quit(&mut self) {
-        self.running = false;
-    }
 }