From 0900a27dfc6c7b04ef370cab2a5bd9f1892867e8 Mon Sep 17 00:00:00 2001
From: Krzysztof Juszczyk <kjuszczyk@antmicro.com>
Date: Fri, 23 Feb 2024 16:20:16 +0100
Subject: [PATCH] [#55213] Include `vte` crate, implement `Perform` trait for
 `Shell` struct

---
 Cargo.lock        |  28 +++++++++++
 Cargo.toml        |   1 +
 src/shell_base.rs | 126 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 155 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index cdc32fd..277965f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -74,6 +74,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "arrayvec"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "96d30a06541fbafbc7f82ed10c06164cfbd2c401138f6addd8404629c4b16711"
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -670,6 +676,27 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 
+[[package]]
+name = "vte"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40eb22ae96f050e0c0d6f7ce43feeae26c348fc4dea56928ca81537cfaa6188b"
+dependencies = [
+ "arrayvec",
+ "utf8parse",
+ "vte_generate_state_changes",
+]
+
+[[package]]
+name = "vte_generate_state_changes"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d257817081c7dffcdbab24b9e62d2def62e2ff7d00b1c20062551e6cccc145ff"
+dependencies = [
+ "proc-macro2",
+ "quote",
+]
+
 [[package]]
 name = "wash"
 version = "0.1.0"
@@ -683,6 +710,7 @@ dependencies = [
  "nix 0.26.4",
  "os_pipe",
  "regex",
+ "vte",
  "wasi",
  "wasi_ext_lib",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index c4ff7a2..0a9de79 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,7 @@ color-eyre = "0.5"
 lazy_static = "1"
 regex = "1"
 glob = "0.3"
+vte = "0.13.0"
 
 [target.'cfg(target_os = "wasi")'.dependencies]
 wasi_ext_lib = { git = "https://github.com/antmicro/wasi_ext_lib.git", branch = "main", features = ["hterm"] }
diff --git a/src/shell_base.rs b/src/shell_base.rs
index 26b84d4..ac84466 100644
--- a/src/shell_base.rs
+++ b/src/shell_base.rs
@@ -26,6 +26,8 @@ use std::path::{Path, PathBuf};
 #[cfg(target_os = "wasi")]
 use wasi;
 
+use vte::{Params, Parser, Perform};
+
 #[cfg(target_os = "wasi")]
 use wasi_ext_lib::termios;
 
@@ -504,6 +506,7 @@ pub struct Shell {
     pub history: Vec<String>,
 
     history_path: PathBuf,
+    input: String,
     should_echo: bool,
     cursor_position: usize,
     insert_mode: bool,
@@ -512,6 +515,128 @@ pub struct Shell {
     reader: InternalReader,
 }
 
+impl Perform for Shell {
+    fn print(&mut self, c: char) {
+        // regular characters
+        if self.cursor_position == self.input.len() {
+            self.input.push(c);
+            self.echo(&c.to_string());
+        } else if self.insert_mode {
+            // in insert mode, when cursor is in the middle, new character expand CLI
+            // instead of replacing charcter under cursor
+            self.input.insert(self.cursor_position, c);
+
+            // for wasi target, we assume that hterm has enabled insert mode
+            #[cfg(target_os = "wasi")]
+            self.echo(&c.to_string());
+
+            #[cfg(not(target_os = "wasi"))]
+            self.echo(&format!("\x1b[@{}", c));
+        } else {
+            self.input.replace_range(
+                self.cursor_position..self.cursor_position + 1,
+                &c.to_string(),
+            );
+
+            self.echo(&c.to_string());
+        }
+
+        self.cursor_position += 1;
+    }
+
+    fn execute(&mut self, byte: u8) {
+        // C0 and C1 control functions
+        match byte {
+            // enter
+            0x10 | 0x13 => {
+                self.echo("\n");
+                self.cursor_position = 0;
+                self.input = self.input.trim().to_string();
+            }
+            // backspace
+            127 => {
+                if !self.input.is_empty() && self.cursor_position > 0 {
+                    self.echo("\x1b[D\x1b[P");
+                    self.input.remove(self.cursor_position - 1);
+                    self.cursor_position -= 1;
+                }
+            }
+            _ => {/* ignore for now */}
+        }
+    }
+
+    fn hook(&mut self, _params: &Params, _intermediates: &[u8], _ignore: bool, _c: char) {
+        /* ignore for now */
+    }
+
+    fn put(&mut self, _byte: u8) {
+        /* ignore for now */
+    }
+
+    fn unhook(&mut self) {
+        /* ignore for now */
+    }
+
+    fn osc_dispatch(&mut self, _params: &[&[u8]], _bell_terminated: bool) {
+        /* ignore for now */
+    }
+
+    fn csi_dispatch(&mut self, params: &Params, _intermediates: &[u8], _ignore: bool, c: char) {
+        if params.len() == 1 {
+            let param = params.iter().next().unwrap();
+            match (param[0], c) {
+                // UpArrow
+                (_, 'A') => {
+
+                }
+                // DownArrow
+                (_, 'B') => {
+
+                }
+                // RightArrow
+                (_, 'C') => {
+
+                }
+                // LeftArrow
+                (_, 'D') => {
+
+                }
+                // End
+                (_, 'F') => {
+
+                }
+                // Home
+                (_, 'H') => {
+
+                }
+                // PageUp
+                (5, '~') => {
+
+                }
+                // PageDown
+                (6, '~') => {
+
+                }
+                // Insert
+                (7, '~') => {
+
+                }
+                // Del
+                (8, '~') => {
+
+                }
+                (_, _) => {
+
+                }
+            }
+        }
+    }
+
+    fn esc_dispatch(&mut self, _intermediates: &[u8], _ignore: bool, _byte: u8) {
+        /* ignore for now */
+    }
+}
+
 impl Shell {
     pub fn new(should_echo: bool, pwd: &str, args: VecDeque<String>) -> Self {
         Shell {
@@ -532,6 +657,7 @@ impl Shell {
                     env!("CARGO_PKG_NAME")
                 )
             }),
+            input: String::new(),
             vars: HashMap::new(),
             last_exit_status: EXIT_SUCCESS,
             last_job_pid: None,