/**
 * Pure cost aggregation over observer episodes.
 *
 * Two layers:
 *   - episodeUsd(episode, pricing) — compute 5-component USD breakdown per episode.
 *   - aggregateDay(episodes, dateISO, pricing) — sum across episodes whose
 *     started_at begins with dateISO ("YYYY-MM-DD").
 *
 * Spec: docs/superpowers/specs/2026-05-24-llm-first-router-overhaul-design.md §12.
 * Consumed by `cost-stop-hook.mjs` and `/brain-retro` aggregations.
 */

export function episodeUsd(episode, pricing) {
  const tc = (episode && episode.task_cost) || {};
  const classifier_usd =
    (tc.classifier_input_tokens || 0) * pricing.sonnet.input +
    (tc.classifier_output_tokens || 0) * pricing.sonnet.output;
  const self_assessment_usd =
    (tc.self_assessment_input_tokens || 0) * pricing.opus.input +
    (tc.self_assessment_output_tokens || 0) * pricing.opus.output;
  const reviewer_subagent_usd = tc.reviewer_subagent_usd || 0;
  const reviewer_direct_fallback_usd = tc.reviewer_direct_fallback_usd || 0;
  const self_retrospect_usd = tc.self_retrospect_usd || 0;
  const judge_spend_usd = tc.judge_spend_usd || 0;
  const total_usd =
    classifier_usd +
    self_assessment_usd +
    reviewer_subagent_usd +
    reviewer_direct_fallback_usd +
    self_retrospect_usd +
    judge_spend_usd;
  return {
    classifier_usd,
    self_assessment_usd,
    reviewer_subagent_usd,
    reviewer_direct_fallback_usd,
    self_retrospect_usd,
    judge_spend_usd,
    total_usd,
  };
}

export function aggregateDay(episodes, dateISO, pricing) {
  const totals = {
    classifier_usd: 0,
    self_assessment_usd: 0,
    reviewer_subagent_usd: 0,
    reviewer_direct_fallback_usd: 0,
    self_retrospect_usd: 0,
    judge_spend_usd: 0,
  };
  let episode_count = 0;
  for (const ep of Array.isArray(episodes) ? episodes : []) {
    if (!ep || !ep.timestamps || typeof ep.timestamps.started_at !== 'string') continue;
    if (!ep.timestamps.started_at.startsWith(dateISO)) continue;
    const u = episodeUsd(ep, pricing);
    totals.classifier_usd += u.classifier_usd;
    totals.self_assessment_usd += u.self_assessment_usd;
    totals.reviewer_subagent_usd += u.reviewer_subagent_usd;
    totals.reviewer_direct_fallback_usd += u.reviewer_direct_fallback_usd;
    totals.self_retrospect_usd += u.self_retrospect_usd;
    totals.judge_spend_usd += u.judge_spend_usd;
    episode_count += 1;
  }
  const total_usd =
    totals.classifier_usd +
    totals.self_assessment_usd +
    totals.reviewer_subagent_usd +
    totals.reviewer_direct_fallback_usd +
    totals.self_retrospect_usd +
    totals.judge_spend_usd;
  return { ...totals, total_usd, episode_count };
}