updated readme + config example

README.md

@@ -4,37 +4,44 @@ mould is a modern Terminal User Interface (TUI) tool designed for interactively
 
 ## Features
 
-- **Universal Format Support**: Handle `.env`, `JSON`, `YAML`, `TOML`, `XML`, `INI`, and `Properties` seamlessly.
+- **Universal Format Support**: Read, edit, and write `.env`, `JSON`, `YAML`, `TOML`, `XML`, `INI`, and `Properties` files seamlessly.
 - **Tree View Navigation**: Edit nested data structures in a beautiful, depth-colored tree view.
-- **Smart Template Discovery**: Rule-based resolver automatically discovers relationships (e.g., `.env.example` vs `.env`, `config.template.properties` vs `config.properties`) and highlights differences.
+- **Smart Template Discovery**: Rule-based resolver automatically discovers relationships (e.g., `.env.example` vs `.env`, `config.template.properties` vs `config.properties`) and highlights missing keys.
 - **Strict Type Preservation**: Intelligently preserves data types (integers, booleans, strings) during edit-save cycles, ensuring your configuration stays valid.
 - **Add Missing Keys**: Instantly pull missing keys and their default values from your template into your active configuration with a single keystroke.
-- **Neovim Integration**: Comes with a built-in Neovim plugin for seamless in-editor configuration management.
-- **Docker Compose Integration**: Automatically generate `docker-compose.override.yml` from `docker-compose.yml`.
+- **Advanced Undo/Redo Engine**: Features a tree-based undo/redo history that ensures you never lose changes during complex branching edits.
 - **Vim-inspired Workflow**: Navigate with `j`/`k`, `gg`/`G`, edit with `i`, search with `/`, and save with `:w`.
-- **Modern UI**: A polished, rounded interface featuring a semantic Catppuccin Mocha palette.
-- **Highly Configurable**: Customize keybindings and semantic themes via a simple TOML configuration.
+- **Modern UI**: A polished, rounded interface featuring a semantic Catppuccin Mocha palette with support for terminal transparency.
+- **Highly Configurable**: Customize keybindings and semantic themes via a simple TOML user configuration.
+- **Neovim Integration**: Comes with a built-in Neovim plugin for seamless in-editor configuration management.
+
+---
 
 ## Installation
 
-### CLI Application
+### 1. CLI Application
+
 Ensure you have Rust and Cargo installed, then run:
 
 ```sh
+# Install directly from the local path
 cargo install --path .
 ```
 
 Alternatively, you can build from source:
 
 ```sh
-git clone <repository_url>
-cd mould
+git clone https://git.narl.io/nvrl/mould-rs
+cd mould-rs
 cargo build --release
+# The executable will be located in target/release/mould
 ```
 
-### Neovim Plugin
-If you use a plugin manager like `mini.deps`, you can add the repository directly:
+### 2. Neovim Plugin
 
+If you want to use `mould` directly inside Neovim, the repository includes a built-in Lua plugin that opens `mould` in a floating terminal buffer and synchronizes the file upon exit.
+
+**Using `mini.deps`:**
 ```lua
 add({
 	source = 'https://git.narl.io/nvrl/mould-rs',
@@ -42,9 +49,11 @@ add({
 })
 ```
 
+---
+
 ## Usage
 
-Provide an input template file to start editing. `mould` is smart enough to figure out if it's looking at a template or an active file, and will search for its counterpart to provide diffing.
+Provide an input template file to start editing. `mould` is smart enough to figure out if it's looking at a template or an active file, and will search for its counterpart to provide live diffing.
 
 ```sh
 mould .env.example
@@ -52,6 +61,12 @@ mould docker-compose.yml
 mould config.template.json -o config.json
 ```
 
+If you just run `mould` in a directory, it will automatically look for common template patterns like `.env.example` or `docker-compose.yml`.
+
+### Inside Neovim
+
+Open any configuration file in Neovim and run `:Mould`. It will launch a floating window targeting your active buffer.
+
 ### Keybindings (Default)
 
 - **Normal Mode**
@@ -60,51 +75,43 @@ mould config.template.json -o config.json
   - `gg`: Jump to the top
   - `G`: Jump to the bottom
   - `i`: Edit value (cursor at start)
-  - `A`: Edit value (cursor at end)
-  - `S`: Substitute value (clear and edit)
-  - `o`: Append a new item to the current array
-  - `O`: Prepend a new item to the current array
-  - `dd`: Delete the currently selected variable or group
+  - `a`: Edit value (cursor at end)
+  - `s`: Substitute value (clear and edit)
+  - `r`: Rename the current key
+  - `o`: Append a new item (as a sibling or array element)
+  - `O`: Prepend a new item
+  - `alt+o` / `alt+O`: Append/Prepend a new group/object
+  - `t`: Toggle between group/object and standard value
+  - `dd`: Delete the currently selected variable or group (removes all nested children)
   - `u`: Undo the last change
+  - `U`: Redo the reverted change
   - `a`: Add missing value from template to active config
-  - `/`: Search for configuration keys (Jump to matches)
-  - `n`: Jump to the next search match
-  - `N`: Jump to the previous search match
-  - `:w` or `Enter`: Save the current configuration to the output file
+  - `/`: Search for configuration keys
+  - `n` / `N`: Jump to next / previous search match
+  - `:w` or `Enter`: Save the current configuration
   - `:q` or `q`: Quit the application
   - `:wq`: Save and quit
   - `Esc`: Clear current command prompt
 
-- **Insert Mode**
-  - Type your value for the selected key.
+- **Insert / Rename Modes**
+  - Type your value/key string.
   - Arrow keys: Navigate within the input field
-  - `Enter` / `Esc`: Commit the value and return to Normal Mode
+  - `Enter`: Commit the value and return to Normal Mode
+  - `Esc`: Cancel edits and return to Normal Mode
+
+---
 
 ## Configuration
 
-mould can be configured using a `config.toml` file located in your user configuration directory (e.g., `~/.config/mould/config.toml` on Linux/macOS).
+`mould` can be configured using a `config.toml` file located in your user configuration directory:
+- **Linux/macOS**: `~/.config/mould/config.toml`
+- **Windows**: `%AppData%\mould\config.toml`
 
 Example configuration:
 
 ```toml
-[keybinds]
-down = "j"
-up = "k"
-edit = "i"
-save = ":w"
-quit = ":q"
-normal_mode = "Esc"
-search = "/"
-next_match = "n"
-previous_match = "N"
-jump_top = "gg"
-jump_bottom = "G"
-
 [theme]
-# Enable transparency to let your terminal background show through
 transparent = false
-
-# Custom color palette (Semantic Catppuccin Mocha defaults)
 bg_normal = "#1e1e2e"
 bg_highlight = "#89b4fa"
 bg_active = "#a6e3a1"
@@ -121,8 +128,60 @@ tree_depth_1 = "#b4befe"
 tree_depth_2 = "#cba6f7"
 tree_depth_3 = "#89b4fa"
 tree_depth_4 = "#fab387"
+
+[keybinds]
+down = "j"
+up = "k"
+edit = "i"
+edit_append = "a"
+edit_substitute = "s"
+save = ":w"
+quit = ":q"
+normal_mode = "Esc"
+search = "/"
+next_match = "n"
+previous_match = "N"
+jump_top = "gg"
+jump_bottom = "G"
+append_item = "o"
+prepend_item = "O"
+delete_item = "dd"
+undo = "u"
+redo = "U"
+rename = "r"
+append_group = "alt+o"
+prepend_group = "alt+O"
+toggle_group = "t"
 ```
 
-## License
+---
 
-This project is licensed under the MIT License. See the [LICENSE](LICENSE) file for details.
+## Development & Architecture
+
+`mould` is written in Rust and architected to decouple the file format parsing from the UI representation. This allows the TUI to render complex, nested configuration files in a unified tree-view.
+
+### Core Architecture
+
+1. **State Management & Undo Tree (`src/app.rs` & `src/undo.rs`)**
+   - The central state is maintained in the `App` struct, which tracks the currently loaded configuration variables, application modes (`Normal`, `Insert`, `InsertKey`, `Search`), and user input buffer.
+   - It integrates an **UndoTree**, providing non-linear, branching history tracking for complex edits (additions, deletions, nested renaming). 
+
+2. **Unified Data Model (`src/format/mod.rs`)**
+   - Regardless of the underlying format, all data is translated into a flattened `Vec<ConfigItem>`.
+   - A `ConfigItem` contains its structural path (`Vec<PathSegment>` handling nested Object Keys and Array Indices), values, type metadata (`ValueType`), and template comparison statuses (e.g., `MissingFromActive`).
+
+3. **Format Handlers (`src/format/*`)**
+   - **`env.rs` & `properties.rs`**: Handlers for flat key-value files.
+   - **`hierarchical.rs`**: A generalized processor leveraging `serde_json::Value` as an intermediary layer to parse and write nested `JSON`, `YAML`, `TOML`, and even `XML` (via `quick-xml` transposition).
+   - **`ini.rs`**: Handles traditional `[Section]` based INI configurations.
+
+4. **Template Resolver (`src/resolver.rs`)**
+   - Automatically determines structural pairings without explicit instruction. 
+   - Uses hardcoded exact rules (e.g., `compose.yml` -> `compose.override.yml`) and generic fallback rules to strip `.example` or `.template` suffixes to find target output files dynamically.
+
+5. **Terminal UI & Event Loop (`src/ui.rs` & `src/runner.rs`)**
+   - **UI Rendering**: Powered by `ratatui`. Renders a conditional side-by-side or vertical layout consisting of a styled hierarchical List, an active Input field, and a status bar indicating keybind availability.
+   - **Event Runner**: Powered by `crossterm`. Intercepts keystrokes, resolves sequences (like `dd` or `gg`), delegates to the `tui-input` backend during active editing, and interacts with the internal API to mutate the configuration tree.
+
+6. **Neovim Plugin (`lua/mould/init.lua`)**
+   - Implements a Lua wrapper that calculates terminal geometries and launches the CLI `mould` binary inside an ephemeral, floating terminal buffer, triggering automatic Neovim `checktime` syncs on exit.

config.example.toml

@@ -31,8 +31,8 @@ tree_depth_4 = "#fab387"
 down = "j"
 up = "k"
 edit = "i"
-edit_append = "A"
-edit_substitute = "S"
+edit_append = "a"
+edit_substitute = "s"
 save = ":w"
 quit = ":q"
 normal_mode = "Esc"
@@ -45,3 +45,8 @@ append_item = "o"
 prepend_item = "O"
 delete_item = "dd"
 undo = "u"
+redo = "U"
+rename = "r"
+append_group = "alt+o"
+prepend_group = "alt+O"
+toggle_group = "t"

src/app.rs

@@ -242,8 +242,13 @@ impl App {
 
     /// Transitions the application into Insert Mode with a specific variant.
     pub fn enter_insert(&mut self, variant: InsertVariant) {
-        if let Some(var) = self.vars.get(self.selected)
-            && !var.is_group {
+        if let Some(var) = self.vars.get(self.selected) {
+            if var.is_group {
+                self.enter_insert_key();
+            } else {
+                if !matches!(variant, InsertVariant::Substitute) {
+                    self.sync_input_with_selected();
+                }
                 self.mode = Mode::Insert;
                 match variant {
                     InsertVariant::Start => {
@@ -259,6 +264,7 @@ impl App {
                     }
                 }
             }
+        }
     }
 
     /// Commits the current input and transitions the application into Normal Mode.
@@ -337,9 +343,9 @@ impl App {
     }
 
     /// Adds a new item relative to the selected item.
-    pub fn add_item(&mut self, after: bool, is_group: bool) {
+    pub fn add_item(&mut self, after: bool, is_group: bool, as_child: bool) {
         if self.vars.is_empty() {
-            let new_key = "NEW_VAR".to_string();
+            let new_key = if is_group { "NEW_GROUP".to_string() } else { "NEW_VAR".to_string() };
             self.vars.push(ConfigItem {
                 key: new_key.clone(),
                 path: vec![PathSegment::Key(new_key)],
@@ -370,8 +376,8 @@ impl App {
         let insert_pos;
         let mut is_array_item = false;
 
-        if let Some(PathSegment::Index(idx)) = selected_item.path.last() {
-            // ARRAY ITEM LOGIC
+        if !as_child && let Some(PathSegment::Index(idx)) = selected_item.path.last() {
+            // ARRAY ITEM LOGIC (Adding sibling to an existing index)
             is_array_item = true;
             let base_path = selected_item.path[..selected_item.path.len() - 1].to_vec();
             let new_idx = if after { idx + 1 } else { *idx };
@@ -392,11 +398,29 @@ impl App {
             new_path = base_path;
             new_path.push(PathSegment::Index(new_idx));
             new_depth = selected_item.depth;
-        } else if after && selected_item.is_group {
+        } else if as_child && selected_item.is_group {
             // ADD AS CHILD OF GROUP
             insert_pos = self.selected + 1;
             new_path = selected_item.path.clone();
             new_depth = selected_item.depth + 1;
+            
+            // Check if this group already contains array items
+            if self.is_array_group(&selected_item.path) {
+                is_array_item = true;
+                let new_idx = 0; // Prepend to array
+                new_path.push(PathSegment::Index(new_idx));
+                
+                // Shift existing children
+                for var in self.vars.iter_mut() {
+                    if var.path.starts_with(&selected_item.path) && var.path.len() > selected_item.path.len()
+                        && let PathSegment::Index(i) = var.path[selected_item.path.len()] {
+                            var.path[selected_item.path.len()] = PathSegment::Index(i + 1);
+                            if var.path.len() == selected_item.path.len() + 1 {
+                                var.key = format!("[{}]", i + 1);
+                            }
+                        }
+                }
+            }
         } else {
             // ADD AS SIBLING
             let parent_path = if selected_item.path.len() > 1 {
@@ -417,6 +441,17 @@ impl App {
             
             new_path = parent_path;
             new_depth = selected_item.depth;
+            
+            // If the parent is an array group, this is also an array item
+            if !new_path.is_empty() && self.is_array_group(&new_path) {
+                is_array_item = true;
+                if let Some(PathSegment::Index(idx)) = selected_item.path.last() {
+                    let new_idx = if after { idx + 1 } else { *idx };
+                    new_path.push(PathSegment::Index(new_idx));
+                } else {
+                    new_path.push(PathSegment::Index(0));
+                }
+            }
         }
 
         // 2. Generate a unique key for non-array items
@@ -458,9 +493,10 @@ impl App {
 
         self.vars.insert(insert_pos, new_item);
         self.selected = insert_pos;
+        self.save_undo_state();
+        
         if is_array_item {
             self.sync_input_with_selected();
-            self.save_undo_state();
             self.enter_insert(InsertVariant::Start);
         } else {
             self.enter_insert_key();
@@ -495,6 +531,14 @@ impl App {
         self.vars.get(self.selected).map(|v| v.is_group).unwrap_or(false)
     }
 
+    pub fn is_array_group(&self, group_path: &[PathSegment]) -> bool {
+        self.vars.iter().any(|v| 
+            v.path.starts_with(group_path) 
+            && v.path.len() == group_path.len() + 1 
+            && matches!(v.path.last(), Some(PathSegment::Index(_)))
+        )
+    }
+
     pub fn selected_is_array(&self) -> bool {
         self.vars.get(self.selected)
             .map(|v| !v.is_group && matches!(v.path.last(), Some(PathSegment::Index(_))))

src/runner.rs

@@ -124,6 +124,9 @@ where
         if !key_str.is_empty() {
             self.key_sequence.push_str(&key_str);
 
+            let mut exact_match = None;
+            let mut prefix_match = false;
+
             // Collect all configured keybinds
             let binds = [
                 (&self.config.keybinds.down, "down"),
@@ -131,6 +134,7 @@ where
                 (&self.config.keybinds.edit, "edit"),
                 (&self.config.keybinds.edit_append, "edit_append"),
                 (&self.config.keybinds.edit_substitute, "edit_substitute"),
+                (&"S".to_string(), "edit_substitute"),
                 (&self.config.keybinds.search, "search"),
                 (&self.config.keybinds.next_match, "next_match"),
                 (&self.config.keybinds.previous_match, "previous_match"),
@@ -150,9 +154,6 @@ where
                 (&"q".to_string(), "quit"),
             ];
 
-            let mut exact_match = None;
-            let mut prefix_match = false;
-
             for (bind, action) in binds.iter() {
                 if bind == &&self.key_sequence {
                     exact_match = Some(*action);
@@ -162,6 +163,21 @@ where
                 }
             }
 
+            if exact_match.is_none() && !prefix_match {
+                // Not a match and not a prefix, restart with current key
+                self.key_sequence.clear();
+                self.key_sequence.push_str(&key_str);
+                
+                for (bind, action) in binds.iter() {
+                    if bind == &&self.key_sequence {
+                        exact_match = Some(*action);
+                        break;
+                    } else if bind.starts_with(&self.key_sequence) {
+                        prefix_match = true;
+                    }
+                }
+            }
+
             if let Some(action) = exact_match {
                 self.key_sequence.clear();
                 match action {
@@ -179,14 +195,14 @@ where
                     "previous_match" => self.app.jump_previous_match(),
                     "jump_top" => self.app.jump_top(),
                     "jump_bottom" => self.app.jump_bottom(),
-                    "append_item" => self.app.add_item(true, false),
-                    "prepend_item" => self.app.add_item(false, false),
+                    "append_item" => self.app.add_item(true, false, false),
+                    "prepend_item" => self.app.add_item(false, false, false),
                     "delete_item" => self.app.delete_selected(),
                     "undo" => self.app.undo(),
                     "redo" => self.app.redo(),
                     "rename" => self.app.enter_insert_key(),
-                    "append_group" => self.app.add_item(true, true),
-                    "prepend_group" => self.app.add_item(false, true),
+                    "append_group" => self.app.add_item(true, true, true),
+                    "prepend_group" => self.app.add_item(false, true, true),
                     "toggle_group" => {
                         self.app.toggle_group_selected();
                         self.app.save_undo_state();
@@ -203,7 +219,6 @@ where
                 }
             } else if !prefix_match {
                 self.key_sequence.clear();
-                self.key_sequence.push_str(&key_str);
             }
         } else {
             // Non-character keys reset the sequence buffer

src/ui.rs

@@ -103,24 +103,30 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
                 Span::styled(&var.key, key_style),
             ];
 
-            // Add status indicator if not present (only for leaf variables)
-            if !var.is_group {
-                match var.status {
-                    crate::format::ItemStatus::MissingFromActive => {
-                        let missing_style = if is_selected {
-                            Style::default().fg(theme.fg_highlight()).add_modifier(Modifier::BOLD)
-                        } else {
-                            Style::default().fg(theme.fg_warning()).add_modifier(Modifier::BOLD)
-                        };
-                        key_spans.push(Span::styled(" (missing)", missing_style));
-                    }
-                    crate::format::ItemStatus::Modified => {
-                        if !is_selected {
-                            key_spans.push(Span::styled(" (*)", Style::default().fg(theme.fg_modified())));
-                        }
-                    }
-                    _ => {}
+            // Add status indicator if not present
+            match var.status {
+                crate::format::ItemStatus::MissingFromActive if !var.is_group => {
+                    let missing_style = if is_selected {
+                        Style::default().fg(theme.fg_highlight()).add_modifier(Modifier::BOLD)
+                    } else {
+                        Style::default().fg(theme.fg_warning()).add_modifier(Modifier::BOLD)
+                    };
+                    key_spans.push(Span::styled(" (missing)", missing_style));
                 }
+                crate::format::ItemStatus::MissingFromActive if var.is_group => {
+                    let missing_style = if is_selected {
+                        Style::default().fg(theme.fg_highlight()).add_modifier(Modifier::BOLD)
+                    } else {
+                        Style::default().fg(theme.fg_warning()).add_modifier(Modifier::BOLD)
+                    };
+                    key_spans.push(Span::styled(" (missing group)", missing_style));
+                }
+                crate::format::ItemStatus::Modified => {
+                    if !is_selected {
+                        key_spans.push(Span::styled(" (*)", Style::default().fg(theme.fg_modified())));
+                    }
+                }
+                _ => {}
             }
 
             let item_style = if is_selected {
@@ -210,7 +216,9 @@ pub fn draw(f: &mut Frame, app: &mut App, config: &Config) {
 
     // Show template value in normal mode if it differs
     let display_text = if let Some(var) = current_var {
-        if var.is_group {
+        if matches!(app.mode, Mode::InsertKey) {
+            input_text.to_string()
+        } else if var.is_group {
             "<group>".to_string()
         } else if matches!(app.mode, Mode::Normal) {
             format!("{}{}", input_text, extra_info)