Add preliminary canvas module (doesn't work)

src/lib/painter/canvas.old.ts

@@ -0,0 +1,125 @@
+import { ANSI_BUFFERS, ANSI_DYNAMIC, writeAnsi } from '../util/ansi';
+import { tryCatch } from '@maxmorozoff/try-catch-tuple';
+
+type CanvasAPI = {
+  clear: () => Promise<void>;
+  moveToOrigin: () => Promise<void>;
+  availableHeight: number;
+  availableWidth: number;
+};
+
+type CleanupHandler = (api: {
+  clear: () => Promise<void>;
+  endPosition: { x: number; y: number };
+}) => Promise<void>;
+
+export function createCanvas(
+  paint: (api: CanvasAPI) => Promise<void>,
+  cleanup?: CleanupHandler
+) {
+  let isActive = true;
+  let origin = { x: 0, y: 0 };
+  let currentEnd = { x: 0, y: 0 };
+
+  const canvasAPI: CanvasAPI = {
+    clear: async () => {
+      await writeAnsi([
+        ANSI_BUFFERS.SAVE_CURSOR,
+        ANSI_DYNAMIC.CURSOR_TO(origin.x, origin.y),
+      ]);
+
+      // Clear each line in the canvas area
+      for (let line = 0; line <= currentEnd.y - origin.y; line++) {
+        await writeAnsi([
+          ANSI_BUFFERS.CLEAR_LINE,
+          ...(line < currentEnd.y - origin.y
+            ? [ANSI_DYNAMIC.CURSOR_DOWN(1)]
+            : []),
+        ]);
+      }
+
+      await writeAnsi([ANSI_BUFFERS.RESTORE_CURSOR]);
+    },
+
+    moveToOrigin: async () => {
+      await writeAnsi([ANSI_DYNAMIC.CURSOR_TO(origin.x, origin.y)]);
+    },
+
+    get availableHeight() {
+      return currentEnd.y - origin.y;
+    },
+
+    get availableWidth() {
+      return currentEnd.x - origin.x;
+    },
+  };
+
+  async function trackPaintArea(fn: () => Promise<void>) {
+    // Save initial cursor position
+    const [_, saveError] = await writeAnsi([ANSI_BUFFERS.SAVE_CURSOR]);
+    if (saveError) throw saveError;
+
+    const [initialPos, initialPosError] = await tryCatch(getCursorPosition);
+    if (initialPosError) {
+      await writeAnsi([ANSI_BUFFERS.RESTORE_CURSOR]);
+      throw initialPosError;
+    }
+    if (initialPos) origin = initialPos;
+
+    // Execute painting
+    await fn();
+
+    // Record new end position
+    const [endPos, endPosError] = await tryCatch(getCursorPosition);
+    if (endPosError) {
+      await writeAnsi([ANSI_BUFFERS.RESTORE_CURSOR]);
+      throw endPosError;
+    }
+    if (endPos) currentEnd = endPos;
+
+    // Restore original cursor
+    await writeAnsi([ANSI_BUFFERS.RESTORE_CURSOR]);
+  }
+
+  return {
+    async paint() {
+      if (!isActive) return;
+      await trackPaintArea(async () => {
+        await canvasAPI.moveToOrigin();
+        await paint(canvasAPI);
+      });
+    },
+
+    async destroy() {
+      if (!isActive) return;
+      isActive = false;
+
+      if (cleanup) {
+        await cleanup({
+          clear: canvasAPI.clear,
+          endPosition: currentEnd,
+        });
+      }
+    },
+  };
+}
+
+async function getCursorPosition(): Promise<{ x: number; y: number }> {
+  const [pos, posError] = await tryCatch(async () => {
+    await Bun.write(Bun.stdout, ANSI_BUFFERS.GET_CURSOR_POSITION);
+
+    let response = '';
+    const decoder = new TextDecoder();
+    for await (const chunk of Bun.stdin.stream()) {
+      response += decoder.decode(chunk);
+      if (response.includes('R')) break;
+    }
+
+    const [_, y, x] = response.match(/\[(\d+);(\d+)R/) || [];
+    if (!x) throw TypeError("The 'x' position was unset.");
+    if (!y) throw TypeError("The 'y' position was unset.");
+    return { x: parseInt(x), y: parseInt(y) };
+  });
+
+  return pos || { x: 0, y: 0 };
+}

src/lib/painter/canvas.ts

@@ -0,0 +1,6 @@
+export const createCanvas = (
+  paint: () => Promise<number, Error>,
+  cleanup?: () => Promise<number, Error>
+) => {
+  return [1];
+};

src/lib/util/ansi.ts

@@ -34,6 +34,7 @@ export const ANSI = {
   BG_WHITE: '\x1B[47m',
 
   // Cursor Control
+  GET_CURSOR_POSITION: '\x1B[6n',
   SAVE_CURSOR: '\x1B[s',
   RESTORE_CURSOR: '\x1B[u',
   CURSOR_TO: (x: number, y: number) => `\x1B[${y};${x}H`,
@@ -47,6 +48,8 @@ export const ANSI = {
   CLEAR_LINE: '\x1B[2K',
   CLEAR_END_LINE: '\x1B[0K',
   CLEAR_START_LINE: '\x1B[1K',
+  CLEAR_TO_END: '\x1B[0J', // From cursor to end of screen
+  CLEAR_TO_START: '\x1B[1J', // From cursor to beginning of screen
   CLEAR_BELOW: '\x1B[J',
 };
 
@@ -82,17 +85,31 @@ export const ANSI_BUFFERS = {
   BG_WHITE: encoder.encode(ANSI.BG_WHITE),
 
   // Cursor Control
+  GET_CURSOR_POSITION: encoder.encode(ANSI.GET_CURSOR_POSITION),
   SAVE_CURSOR: encoder.encode(ANSI.SAVE_CURSOR),
   RESTORE_CURSOR: encoder.encode(ANSI.RESTORE_CURSOR),
+
+  // Screen Control
   CLEAR_SCREEN: encoder.encode(ANSI.CLEAR_SCREEN),
   CLEAR_LINE: encoder.encode(ANSI.CLEAR_LINE),
+  CLEAR_TO_END: encoder.encode(ANSI.CLEAR_TO_END),
+  CLEAR_TO_START: encoder.encode(ANSI.CLEAR_TO_START),
   CLEAR_BELOW: encoder.encode(ANSI.CLEAR_BELOW),
 };
 
+export const ANSI_DYNAMIC = {
+  // Cursor Control
+  CURSOR_TO: (x: number, y: number) => encoder.encode(ANSI.CURSOR_TO(x, y)),
+  CURSOR_UP: (x = 1) => encoder.encode(ANSI.CURSOR_UP(x)),
+  CURSOR_DOWN: (x = 1) => encoder.encode(ANSI.CURSOR_DOWN(x)),
+  CURSOR_FORWARD: (x = 1) => encoder.encode(ANSI.CURSOR_FORWARD(x)),
+  CURSOR_BACK: (x = 1) => encoder.encode(ANSI.CURSOR_BACK(x)),
+};
+
 type AnsiBufferKey = keyof typeof ANSI_BUFFERS;
 
 export async function writeAnsi(
-  codes: AnsiBufferKey[],
+  codes: (AnsiBufferKey | Uint8Array)[],
   text?: string,
   autoReset: boolean = true
 ): Promise<Result<number, Error>> {
@@ -100,7 +117,11 @@ export async function writeAnsi(
 
   // Add requested ANSI codes
   for (const code of codes) {
-    buffers.push(ANSI_BUFFERS[code]);
+    if (code instanceof Uint8Array) {
+      buffers.push(code);
+    } else {
+      buffers.push(ANSI_BUFFERS[code]);
+    }
   }
 
   // Add optional text