// Shared upload handling: keep IDs intact and never silently replace a prompt.
export function parseJsonlExamples(text) {
  const examples = [];
  const prompts = new Map();
  const ids = new Set();
  text.split(/\r?\n/).forEach((line, index) => {
    if (!line.trim()) return;
    const fail = message => { throw new Error(`Line ${index + 1}: ${message}`); };
    let obj;
    try { obj = JSON.parse(line); } catch { fail('invalid JSON'); }
    if (!obj || typeof obj !== 'object' || Array.isArray(obj)) fail('expected a JSON object');
    const llmon = obj.llmon_prompt_dirty || obj.llmon_prompt || obj.prompt;
    if (typeof llmon !== 'string' || !llmon.trim()) fail('missing "llmon_prompt_dirty" field');
    const id = obj.id ?? examples.length;
    if (!(typeof id === 'string' && id.trim()) && !(Number.isSafeInteger(id) && id >= 0)) {
      fail('id must be a non-empty string or a non-negative integer');
    }
    if (ids.has(String(id))) fail(`duplicate id "${id}"; use a unique id for each example`);
    ids.add(String(id));
    examples.push({
      id,
      instruction: String(obj.instruction || '').slice(0, 80),
      has_input: !!String(obj.input || '').trim(),
      num_distractors: Math.max(0, (llmon.match(/<\|open\|>instr<\|:\|>/g) || []).length - 1),
    });
    prompts.set(id, llmon);
  });
  if (!examples.length) throw new Error('Empty file');
  return { examples, prompts };
}

// Browser storage may be disabled in an embedded/private browsing session.
export function readPalettePreference() {
  try { return localStorage.getItem('attn_cb_mode') === '1'; } catch { return false; }
}

export function savePalettePreference(enabled) {
  try { localStorage.setItem('attn_cb_mode', enabled ? '1' : '0'); } catch { /* Use this session's state. */ }
}