buffer its independent, needs fixes

client/src/state/app/buffer.rs

@@ -0,0 +1,67 @@
+// src/state/app/buffer.rs
+
+/// Represents the distinct views or "buffers" the user can navigate.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AppView {
+    Intro,
+    Login,
+    Register,
+    Admin,
+    Form(String),
+    Scratch,
+}
+
+impl AppView {
+    /// Returns the display name for the view.
+    pub fn display_name(&self) -> &str {
+        match self {
+            AppView::Intro => "Intro",
+            AppView::Login => "Login",
+            AppView::Register => "Register",
+            AppView::Admin => "Admin Panel",
+            AppView::Form(name) => name.as_str(),
+            AppView::Scratch => "*scratch*",
+        }
+    }
+}
+
+/// Holds the state related to buffer management (navigation history).
+#[derive(Debug, Clone)]
+pub struct BufferState {
+    pub history: Vec<AppView>,
+    pub active_index: usize,
+}
+
+impl Default for BufferState {
+    fn default() -> Self {
+        Self {
+            history: vec![AppView::Intro], // Start with Intro view
+            active_index: 0,
+        }
+    }
+}
+
+impl BufferState {
+    /// Updates the buffer history and active index.
+    /// If the view already exists, it sets it as active.
+    /// Otherwise, it adds the new view and makes it active.
+    pub fn update_history(&mut self, view: AppView) {
+        let existing_pos = self.history.iter().position(|v| v == &view);
+
+        match existing_pos {
+            Some(pos) => {
+                self.active_index = pos;
+            }
+            None => {
+                self.history.push(view.clone());
+                self.active_index = self.history.len() - 1;
+            }
+        }
+    }
+
+    /// Gets the currently active view.
+    pub fn get_active_view(&self) -> Option<&AppView> {
+        self.history.get(self.active_index)
+    }
+}
+