/**
 * Session goal tracker + verifier prompt. No Bare imports.
 *
 * Done is update_goal({ completed: true }) passing a single-call verifier,
 * not the model merely stopping tool use.
 */

const STATUSES = ['idle', 'planning', 'executing', 'verifying', 'complete', 'blocked'];
const MAX_VERIFIER_RUNS = 5;

function create(objective, opts) {
  opts = opts || {};
  const text = String(objective || '').trim();
  return {
    objective: text,
    criteria: Array.isArray(opts.criteria) ? opts.criteria.map(String) : [],
    status: text ? 'executing' : 'idle',
    gaps: [],
    notes: '',
    verifierRuns: 0,
    verify: opts.verify !== false,
    blockedReason: '',
  };
}

function isActive(g) {
  return !!(g && (g.status === 'planning' || g.status === 'executing' || g.status === 'verifying'));
}

function plannerAddendum(g) {
  if (!g || !g.objective) return '';
  const criteria = (g.criteria || []).length
    ? '\nAcceptance criteria:\n' + g.criteria.map((c, i) => (i + 1) + '. ' + c).join('\n')
    : '';
  return (
    'Active goal: ' +
    g.objective +
    criteria +
    '\nComplete all todos, then call update_goal({ completed: true }).' +
    '\nDo not stop with open todos. If blocked, call update_goal({ blocked_reason: "..." }).'
  );
}

function continuation(g) {
  const gaps = g && g.gaps && g.gaps.length ? '\nGaps: ' + g.gaps.join('; ') : '';
  return (
    'Goal NOT complete — continue. Objective: ' +
    ((g && g.objective) || '') +
    gaps +
    '\nDo not stop until you call update_goal({ completed: true }) or update_goal({ blocked_reason: "..." }).'
  );
}

function verifierPrompt(g, evidence) {
  const prior = (g && g.gaps && g.gaps.length ? g.gaps.join('\n- ') : '(none)');
  return (
    'You are an adversarial verifier. You are NOT the agent that produced the work. ' +
    'Your job is to refute that the objective has been met. Default to achieved: false if uncertain.\n\n' +
    'OBJECTIVE:\n' +
    ((g && g.objective) || '') +
    '\n\nEVIDENCE:\n' +
    String(evidence || '(none)') +
    '\n\nPRIOR_GAPS:\n- ' +
    prior +
    '\n\nReply with JSON only: {"achieved": true|false, "gaps": ["..."]}'
  );
}

function parseVerifier(text) {
  const raw = String(text || '');
  const m = raw.match(/\{[\s\S]*\}/);
  if (!m) {
    const yes = /not refuted|achieved["']?\s*:\s*true/i.test(raw);
    const no = /refuted|not achieved|achieved["']?\s*:\s*false/i.test(raw);
    return { achieved: yes && !no, gaps: no ? ['verifier response was not JSON'] : [] };
  }
  try {
    const j = JSON.parse(m[0]);
    const gaps = Array.isArray(j.gaps) ? j.gaps.map(String) : [];
    return { achieved: !!j.achieved, gaps };
  } catch (_) {
    return { achieved: false, gaps: ['verifier response was not JSON'] };
  }
}

function snapshot(g) {
  if (!g) return null;
  return {
    objective: g.objective,
    criteria: g.criteria || [],
    status: g.status,
    gaps: g.gaps || [],
    notes: g.notes || '',
    verifierRuns: g.verifierRuns || 0,
    verify: g.verify !== false,
    blockedReason: g.blockedReason || '',
  };
}

module.exports = {
  STATUSES,
  MAX_VERIFIER_RUNS,
  create,
  isActive,
  plannerAddendum,
  continuation,
  verifierPrompt,
  parseVerifier,
  snapshot,
};