From 8119f1ec3d690489869ab31c086c1f239b204d03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Tue, 16 Jun 2020 18:00:34 +0900
Subject: [PATCH] Refactor editor module to use state + keymap.

---
 helix-term/src/editor.rs | 85 +++++++++++++++++++++++++---------------
 helix-term/src/keymap.rs |  2 +-
 helix-term/src/main.rs   |  3 +-
 3 files changed, 57 insertions(+), 33 deletions(-)

diff --git a/helix-term/src/editor.rs b/helix-term/src/editor.rs
index 24e2448a..1007dc36 100644
--- a/helix-term/src/editor.rs
+++ b/helix-term/src/editor.rs
@@ -4,60 +4,81 @@ use crossterm::{
     event::{self, read, Event, EventStream, KeyCode, KeyEvent},
     execute, queue, style,
     terminal::{self, disable_raw_mode, enable_raw_mode},
-    Result,
 };
 use futures::{future::FutureExt, select, StreamExt};
 use std::io::{self, stdout, Write};
 use std::path::PathBuf;
 use std::time::Duration;
 
-const HELP: &str = r#"
- - Use q to quit
- - Move cursor with h, j, k, l
-"#;
+use anyhow::Error;
+
+use crate::{keymap, Args};
+use helix_core::{Buffer, State};
 
 pub struct Editor {
-    file: PathBuf,
+    state: Option<State>,
 }
 
 impl Editor {
-    pub async fn print_events() {
+    pub fn new(mut args: Args) -> Result<Self, Error> {
+        let mut editor = Editor { state: None };
+
+        if let Some(file) = args.files.pop() {
+            editor.open(file)?;
+        }
+
+        Ok(editor)
+    }
+
+    pub fn open(&mut self, path: PathBuf) -> Result<(), Error> {
+        let buffer = Buffer::load(path)?;
+        let state = State::new(buffer);
+        self.state = Some(state);
+        Ok(())
+    }
+
+    fn render(&self) {
+        // TODO:
+    }
+
+    pub async fn print_events(&mut self) {
         let mut reader = EventStream::new();
+        let keymap = keymap::default();
+
+        self.render();
+
         loop {
             // Handle key events
             let mut event = reader.next().await;
             match event {
-                Some(Ok(x)) => {
-                    if let Event::Key(KeyEvent {
-                        code: KeyCode::Char(c),
-                        ..
-                    }) = x
-                    {
-                        match c {
-                            'h' => execute!(io::stdout(), cursor::MoveLeft(1)).unwrap(),
-                            'j' => execute!(io::stdout(), cursor::MoveDown(1)).unwrap(),
-                            'k' => execute!(io::stdout(), cursor::MoveUp(1)).unwrap(),
-                            'l' => execute!(io::stdout(), cursor::MoveRight(1)).unwrap(),
-                            'q' => {
-                                execute!(
-                                    io::stdout(),
-                                    style::ResetColor,
-                                    cursor::Show,
-                                    terminal::LeaveAlternateScreen
-                                );
-                                break;
-                            }
-                            _ => println!("{:?}", x),
+                // TODO: handle resize events
+                Some(Ok(Event::Key(KeyEvent {
+                    code: KeyCode::Char('q'),
+                    ..
+                }))) => {
+                    break;
+                }
+                Some(Ok(Event::Key(event))) => {
+                    // TODO: handle modes and sequences (`gg`)
+                    if let Some(command) = keymap.get(&event) {
+                        if let Some(state) = &mut self.state {
+                            // TODO: handle count other than 1
+                            command(state, 1);
+                            self.render();
                         }
                     }
                 }
+                Some(Ok(_)) => {
+                    // unhandled event
+                    ()
+                }
                 Some(Err(x)) => panic!(x),
                 None => break,
             }
         }
     }
 
-    pub fn run() -> Result<()> {
+    pub fn run(&mut self) -> Result<(), Error> {
         enable_raw_mode()?;
 
         let mut stdout = stdout();
@@ -81,7 +102,7 @@ impl Editor {
         }
 
         // No need to `run()`, now we can just block on the main future.
-        smol::block_on(Editor::print_events());
+        smol::block_on(self.print_events());
 
         // Send a shutdown signal.
         drop(s);
@@ -93,6 +114,8 @@ impl Editor {
             t.join().unwrap();
         }
 
-        disable_raw_mode()
+        disable_raw_mode()?;
+
+        Ok(())
     }
 }
diff --git a/helix-term/src/keymap.rs b/helix-term/src/keymap.rs
index 849f7281..25bffd2e 100644
--- a/helix-term/src/keymap.rs
+++ b/helix-term/src/keymap.rs
@@ -94,7 +94,7 @@ macro_rules! hashmap {
 
 type Keymap = HashMap<Key, Command>;
 
-fn default() -> Keymap {
+pub fn default() -> Keymap {
     hashmap!(
         Key {
             code: KeyCode::Char('h'),
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index 1e90d4a2..6e5ec5ff 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -22,7 +22,8 @@ fn main() -> Result<(), Error> {
     let args: Args = argh::from_env();
     println!("{:?}", args.files);
 
-    editor::Editor::run()?;
+    let mut editor = editor::Editor::new(args)?;
+    editor.run();
 
     Ok(())
 }