feat(core): parse terminal control sequences

rabby-core/src/terminal_model/mod.rs

@@ -1,20 +1,49 @@
-#[derive(Debug, Clone, PartialEq, Eq)]
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub enum Color {
+    Default,
+    Ansi(u8),
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub struct CellStyle {
+    pub foreground: Color,
+    pub bold: bool,
+}
+
+impl Default for CellStyle {
+    fn default() -> Self {
+        Self {
+            foreground: Color::Default,
+            bold: false,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Cell {
     pub ch: char,
+    pub style: CellStyle,
 }
 
 impl Default for Cell {
     fn default() -> Self {
-        Self { ch: ' ' }
+        Self {
+            ch: ' ',
+            style: CellStyle::default(),
+        }
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct TerminalGrid {
     cols: u16,
     rows: u16,
     cursor_col: u16,
     cursor_row: u16,
+    style: CellStyle,
+    bracketed_paste: bool,
     cells: Vec<Cell>,
 }
 
@@ -26,19 +55,44 @@ impl TerminalGrid {
             rows,
             cursor_col: 0,
             cursor_row: 0,
+            style: CellStyle::default(),
+            bracketed_paste: false,
             cells: vec![Cell::default(); size],
         }
     }
 
+    pub fn cols(&self) -> u16 {
+        self.cols
+    }
+
+    pub fn rows(&self) -> u16 {
+        self.rows
+    }
+
+    pub fn bracketed_paste_enabled(&self) -> bool {
+        self.bracketed_paste
+    }
+
+    pub fn resize(&mut self, cols: u16, rows: u16) {
+        let mut resized = vec![Cell::default(); usize::from(cols) * usize::from(rows)];
+        let copy_rows = self.rows.min(rows);
+        let copy_cols = self.cols.min(cols);
+        for row in 0..copy_rows {
+            for col in 0..copy_cols {
+                let old_index = usize::from(row) * usize::from(self.cols) + usize::from(col);
+                let new_index = usize::from(row) * usize::from(cols) + usize::from(col);
+                resized[new_index] = self.cells[old_index].clone();
+            }
+        }
+        self.cols = cols;
+        self.rows = rows;
+        self.cursor_col = self.cursor_col.min(cols.saturating_sub(1));
+        self.cursor_row = self.cursor_row.min(rows.saturating_sub(1));
+        self.cells = resized;
+    }
+
     pub fn write_utf8(&mut self, bytes: &[u8]) {
-        let text = String::from_utf8_lossy(bytes);
-        for ch in text.chars() {
-            match ch {
-                '\r' => self.cursor_col = 0,
-                '\n' => self.newline(),
-                _ => self.put_char(ch),
-            }
-        }
+        AnsiParser::default().feed(self, bytes);
     }
 
     pub fn visible_text(&self) -> String {
@@ -54,13 +108,24 @@ impl TerminalGrid {
         self.cells[start..end].iter().map(|cell| cell.ch).collect()
     }
 
+    pub fn cell(&self, col: u16, row: u16) -> Option<&Cell> {
+        if col >= self.cols || row >= self.rows {
+            return None;
+        }
+        self.cells
+            .get(usize::from(row) * usize::from(self.cols) + usize::from(col))
+    }
+
     fn put_char(&mut self, ch: char) {
         if self.cursor_row >= self.rows || self.cursor_col >= self.cols {
             return;
         }
         let index =
             usize::from(self.cursor_row) * usize::from(self.cols) + usize::from(self.cursor_col);
-        self.cells[index].ch = ch;
+        self.cells[index] = Cell {
+            ch,
+            style: self.style,
+        };
         self.cursor_col += 1;
         if self.cursor_col >= self.cols {
             self.newline();
@@ -73,6 +138,82 @@ impl TerminalGrid {
             self.cursor_row += 1;
         }
     }
+
+    fn carriage_return(&mut self) {
+        self.cursor_col = 0;
+    }
+
+    fn clear(&mut self) {
+        self.cells.fill(Cell::default());
+        self.cursor_col = 0;
+        self.cursor_row = 0;
+    }
+
+    fn move_cursor_one_based(&mut self, row: u16, col: u16) {
+        self.cursor_row = row.saturating_sub(1).min(self.rows.saturating_sub(1));
+        self.cursor_col = col.saturating_sub(1).min(self.cols.saturating_sub(1));
+    }
+}
+
+#[derive(Debug, Default, Clone, Copy)]
+pub struct AnsiParser;
+
+impl AnsiParser {
+    pub fn feed(&mut self, grid: &mut TerminalGrid, bytes: &[u8]) {
+        let text = String::from_utf8_lossy(bytes);
+        let mut chars = text.chars().peekable();
+        while let Some(ch) = chars.next() {
+            match ch {
+                '\u{1b}' if chars.peek() == Some(&'[') => {
+                    chars.next();
+                    let mut seq = String::new();
+                    while let Some(next) = chars.next() {
+                        seq.push(next);
+                        if matches!(next, 'A'..='Z' | 'a'..='z' | '~') {
+                            break;
+                        }
+                    }
+                    Self::apply_csi(grid, &seq);
+                }
+                '\r' => grid.carriage_return(),
+                '\n' => grid.newline(),
+                _ => grid.put_char(ch),
+            }
+        }
+    }
+
+    fn apply_csi(grid: &mut TerminalGrid, seq: &str) {
+        if seq == "2J" {
+            grid.clear();
+        } else if seq == "?2004h" {
+            grid.bracketed_paste = true;
+        } else if seq == "?2004l" {
+            grid.bracketed_paste = false;
+        } else if let Some(args) = seq.strip_suffix('m') {
+            Self::apply_sgr(grid, args);
+        } else if let Some(args) = seq.strip_suffix('H') {
+            let mut parts = args.split(';');
+            let row = parts.next().and_then(|p| p.parse().ok()).unwrap_or(1);
+            let col = parts.next().and_then(|p| p.parse().ok()).unwrap_or(1);
+            grid.move_cursor_one_based(row, col);
+        }
+    }
+
+    fn apply_sgr(grid: &mut TerminalGrid, args: &str) {
+        if args.is_empty() || args == "0" {
+            grid.style = CellStyle::default();
+            return;
+        }
+        for code in args.split(';').filter_map(|part| part.parse::<u8>().ok()) {
+            match code {
+                0 => grid.style = CellStyle::default(),
+                1 => grid.style.bold = true,
+                30..=37 => grid.style.foreground = Color::Ansi(code - 30),
+                39 => grid.style.foreground = Color::Default,
+                _ => {}
+            }
+        }
+    }
 }
 
 #[cfg(test)]
@@ -106,4 +247,46 @@ mod tests {
 
         assert!(grid.line_text(0).starts_with("한A"));
     }
+
+    #[test]
+    fn parses_ansi_color_and_reset() {
+        let mut grid = TerminalGrid::new(8, 1);
+
+        grid.write_utf8(b"\x1b[31mR\x1b[0mN");
+
+        assert_eq!(grid.cell(0, 0).unwrap().style.foreground, Color::Ansi(1));
+        assert_eq!(grid.cell(1, 0).unwrap().style.foreground, Color::Default);
+    }
+
+    #[test]
+    fn parses_cursor_movement_and_clear_screen() {
+        let mut grid = TerminalGrid::new(6, 2);
+
+        grid.write_utf8(b"hello\x1b[2;3HZ\x1b[2Jx");
+
+        assert_eq!(grid.line_text(0), "x     ");
+        assert_eq!(grid.line_text(1), "      ");
+    }
+
+    #[test]
+    fn tracks_bracketed_paste_mode() {
+        let mut grid = TerminalGrid::new(4, 1);
+
+        grid.write_utf8(b"\x1b[?2004h");
+        assert!(grid.bracketed_paste_enabled());
+        grid.write_utf8(b"\x1b[?2004l");
+        assert!(!grid.bracketed_paste_enabled());
+    }
+
+    #[test]
+    fn resize_preserves_visible_cells() {
+        let mut grid = TerminalGrid::new(4, 1);
+        grid.write_utf8(b"ab");
+
+        grid.resize(6, 2);
+
+        assert_eq!(grid.cols(), 6);
+        assert_eq!(grid.rows(), 2);
+        assert_eq!(grid.line_text(0), "ab    ");
+    }
 }