export default async function highlightStackAttributions()

in src/extension.ts [239:324]
59 lines of code
9 McCabe index (conditional complexity)

export default async function highlightStackAttributions(): Promise<void> {
	const document = vscode.window.activeTextEditor?.document
	if (!document) return;

	const config = vscode.workspace.getConfiguration("llm");
	const attributionWindowSize = config.get("attributionWindowSize") as number;
	const attributionEndpoint = config.get("attributionEndpoint") as string;

	// get cursor postion and offset
	const cursorPosition = vscode.window.activeTextEditor?.selection.active;
	if (!cursorPosition) return;
	const cursorOffset = document.offsetAt(cursorPosition);

	const start = Math.max(0, cursorOffset - attributionWindowSize);
	const end = Math.min(document.getText().length, cursorOffset + attributionWindowSize);

	// Select the start to end span
	if (!vscode.window.activeTextEditor) return;
	vscode.window.activeTextEditor.selection = new vscode.Selection(document.positionAt(start), document.positionAt(end));
	// new Range(document.positionAt(start), document.positionAt(end));


	const text = document.getText();
	const textAroundCursor = text.slice(start, end);

	const body = { document: textAroundCursor };

	// notify user request has started
	void vscode.window.showInformationMessage("Searching for nearby code in the stack...");

	const resp = await fetch(attributionEndpoint, {
		method: "POST",
		body: JSON.stringify(body),
		headers: { "Content-Type": "application/json" },
	});

	if (!resp.ok) {
		return;
	}

	const json = await resp.json() as any as { spans: [number, number][] }
	const { spans } = json

	if (spans.length === 0) {
		void vscode.window.showInformationMessage("No code found in the stack");
		return;
	}

	void vscode.window.showInformationMessage("Highlighted code was found in the stack.",
		"Go to stack search"
	).then(clicked => {
		if (clicked) {
			// open stack search url in browser
			void vscode.env.openExternal(vscode.Uri.parse("https://huggingface.co/spaces/bigcode/search"));
		}
	});

	// combine overlapping spans
	const combinedSpans: [number, number][] = spans.reduce((acc, span) => {
		const [s, e] = span;
		if (acc.length === 0) return [[s, e]];
		const [lastStart, lastEnd] = acc[acc.length - 1];
		if (s <= lastEnd) {
			acc[acc.length - 1] = [lastStart, Math.max(lastEnd, e)];
		} else {
			acc.push([s, e]);
		}
		return acc;
	}, [] as [number, number][]);

	const decorations = combinedSpans.map(([startChar, endChar]) => ({ range: new vscode.Range(document.positionAt(startChar + start), document.positionAt(endChar + start)), hoverMessage: "This code might be in the stack!" }))

	// console.log("Highlighting", decorations.map(d => [d.range.start, d.range.end]));

	const decorationType = vscode.window.createTextEditorDecorationType({
		color: 'red',
		textDecoration: 'underline',

	});

	vscode.window.activeTextEditor?.setDecorations(decorationType, decorations);

	setTimeout(() => {
		vscode.window.activeTextEditor?.setDecorations(decorationType, []);
	}, 5000);
}