/**
 * Normalize QVAC completion stream events for cap-chunk (keep under NMH ~1 MB).
 */

const MAX_DELTA = 64 * 1024;

function clip(s) {
  const t = s == null ? '' : String(s);
  if (t.length <= MAX_DELTA) return t;
  return t.slice(0, MAX_DELTA);
}

function normalizeCompletionEvent(ev) {
  if (!ev || !ev.type) return null;
  if (ev.type === 'contentDelta') {
    return { type: 'contentDelta', delta: clip(ev.delta || ev.text || ev.content || '') };
  }
  if (ev.type === 'thinkingDelta') {
    return { type: 'thinkingDelta', delta: clip(ev.delta || ev.text || ev.content || '') };
  }
  if (ev.type === 'toolCall') {
    const call = ev.call || ev.toolCall || ev;
    return {
      type: 'toolCall',
      call: {
        id: call.id,
        name: call.name,
        arguments: call.arguments != null ? call.arguments : call.args,
      },
    };
  }
  if (ev.type === 'rawDelta') {
    return { type: 'rawDelta', delta: clip(ev.delta) };
  }
  return { type: ev.type, delta: ev.delta != null ? clip(ev.delta) : undefined, call: ev.call };
}

module.exports = { normalizeCompletionEvent, MAX_DELTA };