1 files changed, 66 insertions, 0 deletions
diff --git a/src/repl/highlighter.rs b/src/repl/highlighter.rs
new file mode 100644
index 0000000..593c307
--- /dev/null
+++ b/src/repl/highlighter.rs
@@ -0,0 +1,66 @@
+use crate::config::SharedConfig;
+
+use nu_ansi_term::{Color, Style};
+use reedline::{Highlighter, StyledText};
+
+const MATCH_COLOR: Color = Color::Green;
+
+pub struct ReplHighlighter {
+    external_commands: Vec<String>,
+    config: SharedConfig,
+}
+
+impl ReplHighlighter {
+    /// Construct the default highlighter with a given set of extern commands/keywords to detect and highlight
+    pub fn new(config: SharedConfig, external_commands: Vec<String>) -> ReplHighlighter {
+        Self {
+            config,
+            external_commands,
+        }
+    }
+}
+
+impl Highlighter for ReplHighlighter {
+    fn highlight(&self, line: &str, _cursor: usize) -> StyledText {
+        let mut styled_text = StyledText::new();
+        let color = if self.config.read().light_theme {
+            Color::Black
+        } else {
+            Color::White
+        };
+        let match_color = match self.config.read().highlight {
+            true => MATCH_COLOR,
+            false => color,
+        };
+
+        if self
+            .external_commands
+            .clone()
+            .iter()
+            .any(|x| line.contains(x))
+        {
+            let matches: Vec<&str> = self
+                .external_commands
+                .iter()
+                .filter(|c| line.contains(*c))
+                .map(std::ops::Deref::deref)
+                .collect();
+            let longest_match = matches.iter().fold("".to_string(), |acc, &item| {
+                if item.len() > acc.len() {
+                    item.to_string()
+                } else {
+                    acc
+                }
+            });
+            let buffer_split: Vec<&str> = line.splitn(2, &longest_match).collect();
+
+            styled_text.push((Style::new().fg(color), buffer_split[0].to_string()));
+            styled_text.push((Style::new().fg(match_color), longest_match));
+            styled_text.push((Style::new().fg(color), buffer_split[1].to_string()));
+        } else {
+            styled_text.push((Style::new().fg(color), line.to_string()));
+        }
+
+        styled_text
+    }
+}