From c155247f1d48981119bcb1d539644c6c3e2445f0 Mon Sep 17 00:00:00 2001
From: Drew Galbraith <dgalbraith33@gmail.com>
Date: Wed, 14 Aug 2024 07:49:06 -0700
Subject: [PATCH] [Teton] Terminal now owns the command str.

---
 rust/sys/teton/src/console.rs  | 43 +++++-------------
 rust/sys/teton/src/main.rs     |  4 +-
 rust/sys/teton/src/terminal.rs | 80 +++++++++++++++++++++++++++++++++-
 3 files changed, 89 insertions(+), 38 deletions(-)

diff --git a/rust/sys/teton/src/console.rs b/rust/sys/teton/src/console.rs
index e90e841..2e282dc 100644
--- a/rust/sys/teton/src/console.rs
+++ b/rust/sys/teton/src/console.rs
@@ -4,56 +4,33 @@ use crate::psf::Psf;
 pub struct Console {
     framebuffer: Framebuffer,
     psf: Psf,
-    row: u32,
-    col: u32,
 }
 
 impl Console {
     pub fn new(framebuffer: Framebuffer, psf: Psf) -> Self {
-        Self {
-            framebuffer,
-            psf,
-            row: 0,
-            col: 0,
-        }
+        Self { framebuffer, psf }
     }
 
-    fn incr_cursor(&mut self) {
-        self.col += 1;
-        if self.col >= self.cols() {
-            self.col = 0;
-            self.row += 1;
+    pub fn write_char(&mut self, chr: char, row: u32, col: u32) {
+        if row >= self.rows() {
+            panic!("Write at row {}, max is {}", row, self.rows())
         }
-
-        if self.row >= self.rows() {
-            panic!("Scroll unimplemented")
-        }
-    }
-
-    pub fn write_char(&mut self, chr: char) {
-        if chr == '\x08' {
-            // Backspace.
-            if self.col > 1 {
-                self.col -= 1;
-                self.write_char(' ');
-                self.col -= 1;
-            }
-            return;
+        if col >= self.cols() {
+            panic!("Write at col {}, max is {}", col, self.cols())
         }
         let glyph = self.psf.glyph(chr as u32);
         self.framebuffer.draw_glyph(
             glyph,
-            self.row * (self.psf.height() + 1),
-            self.col * (self.psf.width() + 1),
+            row * (self.psf.height() + 1),
+            col * (self.psf.width() + 1),
         );
-        self.incr_cursor()
     }
 
-    fn cols(&self) -> u32 {
+    pub fn cols(&self) -> u32 {
         self.framebuffer.width() / (self.psf.width() + 1)
     }
 
-    fn rows(&self) -> u32 {
+    pub fn rows(&self) -> u32 {
         self.framebuffer.height() / (self.psf.height() + 1)
     }
 }
diff --git a/rust/sys/teton/src/main.rs b/rust/sys/teton/src/main.rs
index 73765a5..b1866d2 100644
--- a/rust/sys/teton/src/main.rs
+++ b/rust/sys/teton/src/main.rs
@@ -38,9 +38,7 @@ extern "C" fn main() -> z_err_t {
         .expect("Failed to create framebuffer");
 
     let psf = psf::Psf::new("/default8x16.psfu").expect("Failed to open font file.");
-    let mut console = console::Console::new(framebuffer, psf);
-    console.write_char('>');
-
+    let console = console::Console::new(framebuffer, psf);
     let terminal = Rc::new(RefCell::new(terminal::Terminal::new(console)));
 
     let kb_listener = KeyboardListener::new(terminal).expect("Failed to create keyboard listener");
diff --git a/rust/sys/teton/src/terminal.rs b/rust/sys/teton/src/terminal.rs
index 436fd48..1823de7 100644
--- a/rust/sys/teton/src/terminal.rs
+++ b/rust/sys/teton/src/terminal.rs
@@ -1,18 +1,94 @@
+use core::str::Split;
+
 use crate::console::Console;
+use alloc::{
+    format,
+    string::{String, ToString},
+};
 use voyageurs::listener::KeyboardHandler;
 
 pub struct Terminal {
     console: Console,
+    curr_cmd: String,
+    cwd: String,
+    row: u32,
 }
 
 impl KeyboardHandler for Terminal {
     fn handle_char(&mut self, c: char) {
-        self.console.write_char(c)
+        let mut should_execute = false;
+        match c {
+            '\x08' => {
+                let mut chars = self.curr_cmd.chars();
+                chars.next_back(); // Pop last char.
+                self.curr_cmd = chars.collect();
+            }
+            '\n' => should_execute = true,
+            _ => self.curr_cmd.push(c),
+        }
+        self.rewrite_command();
+        if should_execute {
+            self.execute_command();
+            self.rewrite_command();
+        }
     }
 }
 
 impl Terminal {
     pub fn new(console: Console) -> Self {
-        Self { console }
+        let mut term = Self {
+            console,
+            curr_cmd: String::new(),
+            cwd: "/".to_string(),
+            row: 0,
+        };
+        term.rewrite_command();
+        term
+    }
+
+    fn rewrite_command(&mut self) {
+        self.console.write_char('>', self.row, 0);
+
+        let mut col = 1;
+        for c in self.curr_cmd.chars() {
+            self.console.write_char(c, self.row, col);
+            col += 1;
+        }
+
+        // Hacky way to properly backspace.
+        // FIXME: This won't work once we have line wrapping.
+        self.console.write_char(' ', self.row, col)
+    }
+
+    fn write_line(&mut self, line: &str) {
+        let mut col = 0;
+        for c in line.chars() {
+            self.console.write_char(c, self.row, col);
+            col += 1;
+        }
+
+        self.row += 1
+    }
+
+    fn execute_command(&mut self) {
+        self.row += 1;
+
+        let curr_cmd = self.curr_cmd.clone();
+        let mut tokens = curr_cmd.split(' ');
+
+        match tokens.next() {
+            None => {}
+            Some(command) => self.execute_command_parsed(command, tokens),
+        }
+
+        self.curr_cmd.clear()
+    }
+
+    fn execute_command_parsed(&mut self, cmd: &str, _args: Split<'_, char>) {
+        match cmd {
+            "help" => self.write_line("Available commands are 'pwd', 'ls', 'cd', and 'exec'"),
+            "pwd" => self.write_line(&self.cwd.clone()),
+            _ => self.write_line(&format!("Unrecognized command: {}", cmd)),
+        }
     }
 }