Added (as yet unused) chunkText function to split long text messages across multiple payloads.

src/lib/device.ts

@@ -14,6 +14,49 @@ export function getRandomId(): number {
 	return Math.floor(Math.random() * 4294967295);
 }
 
+function chunkText(str: string): string[] {
+	const arr = str.trim().split(/(\s+)/);
+	const ret: string[] = [];
+	let s: string = '';
+	// @ts-expect-error shut up
+	const t = new TextEncoder();
+	for (let n = 0; n < arr.length; n++) {
+		const ss = s + arr[n];
+		const u8a = t.encode(ss);
+		if (u8a.byteLength < MAX_PAYLOAD) { // We are not yet at capacity
+			s = ss; // Grow the current string, do not append to ret since we still have space left
+		} else if (u8a.byteLength === MAX_PAYLOAD) { // We've reached capacity,
+			ret.push(ss.trim()); // Append current string to ret
+			s = ''; // Reset current string
+		} else { // Appending this word to the current string would exceed capacity
+			const st = s.trim();
+			if (st !== '') ret.push(st); // Append the current string to ret as long as it isn't empty
+			s = ''; // Reset current string
+			const u8a = t.encode(arr[n]);
+			if (u8a.byteLength > MAX_PAYLOAD) { // This word alone exceeds payload length, break it up
+				for (let l = 0; l < arr[n].length; l++) { // Walk it character-by-character
+					const ss = s + arr[n].substring(l, l + 1); // Temp value for current string + this char
+					const u8a = t.encode(ss);
+					if (u8a.byteLength > MAX_PAYLOAD) { // If adding this char to the current string would exceed capacity
+						const st = s.trim();
+						if (st !== '') ret.push(st); // Push the current string to ret if non empty
+						s = arr[n].substring(l, l + 1); // Set current string to this char
+					} else { // We can add this char to the current string
+						s = ss;
+					}
+				}
+			} else { // Add this word to the current string
+				s += arr[n];
+			}
+		}
+		if (n === arr.length - 1) {
+			const st = s.trim(); // Ditto
+			if (st !== '') ret.push(s);
+		}
+	}
+	return ret;
+}
+
 export default abstract class Device extends js.global.EventEmitter {
 
 	/** @param debug Enable debug logging (all sent and received frames, etc. - noisy) */