feat: Initial clean release of CHM

packages/lib/services/ai/tools/utils/applyNoteEdits.ts

@@ -0,0 +1,142 @@
+import type { EditOp } from '../buildEditorTools';
+import findFencedBlock from '../../utils/findFencedBlock';
+
+export type ApplyEditStatus = 'applied' | 'anchor-not-found' | 'invalid';
+
+
+// Structured-document fences where the model regenerates the whole block —
+// plain code fences (```js, ```python) are deliberately excluded.
+export const supportedStructuredBlockTags = ['jsoncanvas', 'mermaid', 'abc', 'fountain'];
+
+export const structuredBlockTags = new Set<string>([...supportedStructuredBlockTags]);
+
+export interface AppliedEdit {
+	op: EditOp;
+	status: ApplyEditStatus;
+}
+
+export interface EditApplicationResult {
+	newBody: string;
+	appliedEdits: AppliedEdit[];
+}
+
+const findAnchor = (body: string, anchor: string, cursorPos: number) => {
+	if (!anchor) return -1;
+
+	const first = body.indexOf(anchor);
+	if (first === -1) return -1;
+
+	// Prefer the occurrence closest to the cursor — matches user intent.
+	const second = body.indexOf(anchor, first + 1);
+	if (second === -1) return first;
+
+	let bestIndex = first;
+	let bestDistance = Math.abs(first - cursorPos);
+	let next = second;
+	while (next !== -1) {
+		const distance = Math.abs(next - cursorPos);
+		if (distance < bestDistance) {
+			bestDistance = distance;
+			bestIndex = next;
+		}
+		next = body.indexOf(anchor, next + 1);
+	}
+	return bestIndex;
+};
+
+const isValidEdit = (edit: EditOp, bodyLength: number): boolean => {
+	if (!edit || typeof edit !== 'object') return false;
+	if (typeof edit.op !== 'string') return false;
+
+	switch (edit.op) {
+	case 'appendToNote':
+	case 'replaceSelection':
+		return typeof edit.text === 'string';
+	case 'insertBefore':
+	case 'insertAfter':
+		return typeof edit.anchor === 'string' && edit.anchor.length > 0 && typeof edit.text === 'string';
+	case 'replaceRange':
+		if (typeof edit.anchor !== 'string' || !edit.anchor.length) return false;
+		if (typeof edit.text !== 'string') return false;
+		// Anchor >50% of body is almost certainly a mis-pick — would nuke it.
+		if (edit.anchor.length > bodyLength * 0.5) return false;
+		return true;
+	case 'replaceFencedBlock':
+		if (typeof edit.tag !== 'string' || !structuredBlockTags.has(edit.tag)) return false;
+		if (typeof edit.text !== 'string') return false;
+		return true;
+	default:
+		return false;
+	}
+};
+
+// Edits apply sequentially against the running newBody — a later anchor
+// targeting text removed by an earlier edit won't be found. replaceSelection
+// is body-independent and handled by the caller via the editor command.
+export const applyAnchorEdits = (
+	body: string,
+	edits: EditOp[],
+	cursorPos: number,
+): EditApplicationResult => {
+	let newBody = body;
+	const appliedEdits: AppliedEdit[] = [];
+
+	for (const edit of edits) {
+		if (!isValidEdit(edit, newBody.length)) {
+			appliedEdits.push({ op: edit, status: 'invalid' });
+			continue;
+		}
+
+		if (edit.op === 'replaceSelection') {
+			// Caller applies this via the editor; mark as done so it isn't retried.
+			appliedEdits.push({ op: edit, status: 'applied' });
+			continue;
+		}
+
+		if (edit.op === 'appendToNote') {
+			// Markdown paragraph breaks need a blank line.
+			let sep = '';
+			if (newBody.length) {
+				if (newBody.endsWith('\n\n')) sep = '';
+				else if (newBody.endsWith('\n')) sep = '\n';
+				else sep = '\n\n';
+			}
+			newBody = `${newBody}${sep}${edit.text}`;
+			appliedEdits.push({ op: edit, status: 'applied' });
+			continue;
+		}
+
+		if (edit.op === 'replaceFencedBlock') {
+			// Replace-only — creating a missing block is appendToNote's job.
+			const match = findFencedBlock(newBody, edit.tag, cursorPos);
+			if (!match) {
+				appliedEdits.push({ op: edit, status: 'anchor-not-found' });
+				continue;
+			}
+			const start = match.index;
+			const end = start + match[0].length;
+			const inner = edit.text.endsWith('\n') ? edit.text : `${edit.text}\n`;
+			newBody = `${newBody.slice(0, start)}\`\`\`${edit.tag}\n${inner}\`\`\`${newBody.slice(end)}`;
+			appliedEdits.push({ op: edit, status: 'applied' });
+			continue;
+		}
+
+		const index = findAnchor(newBody, edit.anchor, cursorPos);
+		if (index === -1) {
+			appliedEdits.push({ op: edit, status: 'anchor-not-found' });
+			continue;
+		}
+
+		if (edit.op === 'insertBefore') {
+			newBody = `${newBody.slice(0, index)}${edit.text}${newBody.slice(index)}`;
+		} else if (edit.op === 'insertAfter') {
+			const insertAt = index + edit.anchor.length;
+			newBody = `${newBody.slice(0, insertAt)}${edit.text}${newBody.slice(insertAt)}`;
+		} else if (edit.op === 'replaceRange') {
+			newBody = `${newBody.slice(0, index)}${edit.text}${newBody.slice(index + edit.anchor.length)}`;
+		}
+		appliedEdits.push({ op: edit, status: 'applied' });
+	}
+
+	return { newBody, appliedEdits };
+};