52 lines
1.5 KiB
TypeScript
52 lines
1.5 KiB
TypeScript
// Utilities for splitting outbound text into platform-sized chunks without
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// unintentionally breaking on newlines. Using [\s\S] keeps newlines inside
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// the chunk so messages are only split when they truly exceed the limit.
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export function chunkText(text: string, limit: number): string[] {
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if (!text) return [];
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if (limit <= 0) return [text];
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if (text.length <= limit) return [text];
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const chunks: string[] = [];
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let remaining = text;
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while (remaining.length > limit) {
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const window = remaining.slice(0, limit);
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// 1) Prefer a newline break inside the window.
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let breakIdx = window.lastIndexOf("\n");
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// 2) Otherwise prefer the last whitespace (word boundary) inside the window.
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if (breakIdx <= 0) {
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for (let i = window.length - 1; i >= 0; i--) {
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if (/\s/.test(window[i])) {
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breakIdx = i;
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break;
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}
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}
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}
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// 3) Fallback: hard break exactly at the limit.
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if (breakIdx <= 0) breakIdx = limit;
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const rawChunk = remaining.slice(0, breakIdx);
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const chunk = rawChunk.trimEnd();
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if (chunk.length > 0) {
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chunks.push(chunk);
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}
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// If we broke on whitespace/newline, skip that separator; for hard breaks keep it.
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const brokeOnSeparator =
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breakIdx < remaining.length && /\s/.test(remaining[breakIdx]);
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const nextStart = Math.min(
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remaining.length,
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breakIdx + (brokeOnSeparator ? 1 : 0),
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);
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remaining = remaining.slice(nextStart).trimStart();
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}
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if (remaining.length) chunks.push(remaining);
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return chunks;
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}
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