1 files changed, 121 insertions, 0 deletions
diff --git a/src/repl/init.rs b/src/repl/init.rs
new file mode 100644
index 0000000..f640deb
--- /dev/null
+++ b/src/repl/init.rs
@@ -0,0 +1,121 @@
+use super::Repl;
+
+use crate::config::{Config, SharedConfig};
+
+use anyhow::{Context, Result};
+use reedline::{
+    default_emacs_keybindings, ColumnarMenu, DefaultCompleter, DefaultPrompt, DefaultPromptSegment,
+    Emacs, FileBackedHistory, KeyCode, KeyModifiers, Keybindings, Reedline, ReedlineEvent,
+    ReedlineMenu, ValidationResult, Validator,
+};
+
+use super::REPL_COMMANDS;
+
+const MENU_NAME: &str = "completion_menu";
+
+impl Repl {
+    pub fn init(config: SharedConfig) -> Result<Self> {
+        let multiline_commands: Vec<&'static str> = REPL_COMMANDS
+            .iter()
+            .filter(|(_, _, v)| *v)
+            .map(|(v, _, _)| *v)
+            .collect();
+        let completer = Self::create_completer(config);
+        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_history(history)
+            .with_menu(menu)
+            .with_edit_mode(edit_mode)
+            .with_quick_completions(true)
+            .with_partial_completions(true)
+            .with_validator(Box::new(ReplValidator { multiline_commands }))
+            .with_ansi_colors(true);
+        let prompt = Self::create_prompt();
+        Ok(Self { editor, prompt })
+    }
+
+    fn create_prompt() -> DefaultPrompt {
+        DefaultPrompt::new(DefaultPromptSegment::Empty, DefaultPromptSegment::Empty)
+    }
+
+    fn create_completer(config: SharedConfig) -> DefaultCompleter {
+        let mut completion: Vec<String> = REPL_COMMANDS
+            .into_iter()
+            .map(|(v, _, _)| v.to_string())
+            .collect();
+        completion.extend(config.borrow().repl_completions());
+        let mut completer = DefaultCompleter::with_inclusions(&['.', '-', '_']).set_min_word_len(2);
+        completer.insert(completion.clone());
+        completer
+    }
+
+    fn create_keybindings() -> Keybindings {
+        let mut keybindings = default_emacs_keybindings();
+        keybindings.add_binding(
+            KeyModifiers::NONE,
+            KeyCode::Tab,
+            ReedlineEvent::UntilFound(vec![
+                ReedlineEvent::Menu(MENU_NAME.to_string()),
+                ReedlineEvent::MenuNext,
+            ]),
+        );
+        keybindings.add_binding(
+            KeyModifiers::CONTROL,
+            KeyCode::Char('l'),
+            ReedlineEvent::ExecuteHostCommand(".clear screen".into()),
+        );
+        keybindings
+    }
+
+    fn create_menu() -> ReedlineMenu {
+        let completion_menu = ColumnarMenu::default().with_name(MENU_NAME);
+        ReedlineMenu::EngineCompleter(Box::new(completion_menu))
+    }
+
+    fn create_history() -> Result<Box<FileBackedHistory>> {
+        Ok(Box::new(
+            FileBackedHistory::with_file(1000, Config::history_file()?)
+                .with_context(|| "Failed to setup history file")?,
+        ))
+    }
+}
+
+struct ReplValidator {
+    multiline_commands: Vec<&'static str>,
+}
+
+impl Validator for ReplValidator {
+    fn validate(&self, line: &str) -> ValidationResult {
+        if line.split('"').count() % 2 == 0 || incomplete_brackets(line, &self.multiline_commands) {
+            ValidationResult::Incomplete
+        } else {
+            ValidationResult::Complete
+        }
+    }
+}
+
+fn incomplete_brackets(line: &str, multiline_commands: &[&str]) -> bool {
+    let mut balance: Vec<char> = Vec::new();
+    let line = line.trim_start();
+    if !multiline_commands.iter().any(|v| line.starts_with(v)) {
+        return false;
+    }
+
+    for c in line.chars() {
+        if c == '{' {
+            balance.push('}');
+        } else if c == '}' {
+            if let Some(last) = balance.last() {
+                if last == &c {
+                    balance.pop();
+                }
+            }
+        }
+    }
+
+    !balance.is_empty()
+}