feat: support light theme (#65)

There are two ways to enable the light theme:
- add `light_theme: true` to config.yaml
- use `AICHAT_LIGHT_THEME=true` env var

1 files changed, 26 insertions, 7 deletions

diff --git a/src/repl/init.rs b/src/repl/init.rs
index 7d0c2bb..ff75eff 100644
--- a/src/repl/init.rs
+++ b/src/repl/init.rs
@@ -3,12 +3,17 @@ use super::REPL_COMMANDS;
 use crate::config::{Config, SharedConfig};
 
 use anyhow::{Context, Result};
+use nu_ansi_term::Color;
 use reedline::{
     default_emacs_keybindings, ColumnarMenu, DefaultCompleter, DefaultValidator, Emacs,
-    FileBackedHistory, KeyCode, KeyModifiers, Keybindings, Reedline, ReedlineEvent, ReedlineMenu,
+    ExampleHighlighter, FileBackedHistory, KeyCode, KeyModifiers, Keybindings, Reedline,
+    ReedlineEvent, ReedlineMenu,
 };
 
 const MENU_NAME: &str = "completion_menu";
+const MATCH_COLOR: Color = Color::Green;
+const NEUTRAL_COLOR: Color = Color::White;
+const NEUTRAL_COLOR_LIGHT: Color = Color::Black;
 
 pub struct Repl {
     pub editor: Reedline,
@@ -16,13 +21,20 @@ pub struct Repl {
 
 impl Repl {
     pub fn init(config: SharedConfig) -> Result<Self> {
-        let completer = Self::create_completer(config);
+        let commands: Vec<String> = REPL_COMMANDS
+            .into_iter()
+            .map(|(v, _)| v.to_string())
+            .collect();
+
+        let completer = Self::create_completer(config.clone(), &commands);
+        let highlighter = Self::create_highlighter(config, &commands);
         let keybindings = Self::create_keybindings();
         let history = Self::create_history()?;
         let menu = Self::create_menu();
         let edit_mode = Box::new(Emacs::new(keybindings));
         let editor = Reedline::create()
             .with_completer(Box::new(completer))
+            .with_highlighter(Box::new(highlighter))
             .with_history(history)
             .with_menu(menu)
             .with_edit_mode(edit_mode)
@@ -33,17 +45,24 @@ impl Repl {
         Ok(Self { editor })
     }
 
-    fn create_completer(config: SharedConfig) -> DefaultCompleter {
-        let mut completion: Vec<String> = REPL_COMMANDS
-            .into_iter()
-            .map(|(v, _)| v.to_string())
-            .collect();
+    fn create_completer(config: SharedConfig, commands: &[String]) -> DefaultCompleter {
+        let mut completion = commands.to_vec();
         completion.extend(config.lock().repl_completions());
         let mut completer = DefaultCompleter::with_inclusions(&['.', '-', '_']).set_min_word_len(2);
         completer.insert(completion.clone());
         completer
     }
 
+    fn create_highlighter(config: SharedConfig, commands: &[String]) -> ExampleHighlighter {
+        let mut highlighter = ExampleHighlighter::new(commands.to_vec());
+        if config.lock().light_theme {
+            highlighter.change_colors(MATCH_COLOR, NEUTRAL_COLOR_LIGHT, NEUTRAL_COLOR_LIGHT);
+        } else {
+            highlighter.change_colors(MATCH_COLOR, NEUTRAL_COLOR, NEUTRAL_COLOR);
+        }
+        highlighter
+    }
+
     fn create_keybindings() -> Keybindings {
         let mut keybindings = default_emacs_keybindings();
         keybindings.add_binding(