portal/tools/enforce-override-limit.mjs

// PreToolUse hook: hard-block 6th+ usage of same override-phrase in one day.
// Phase 2 of router-hooks fixes (per brain-retro #9 candidate 6 + self-retrospect 28.05).
//
// Reads:
//   - hook input JSON (passed via stdin)
//   - ~/.claude/runtime/override-usage.jsonl (today's usage log)
//   - tools/enforce-override-vocab.json (7 phrases)
//
// Writes (stdout):
//   - empty if no block
//   - JSON {decision: "block", reason: "..."} if 6th phrase usage detected
//
// Bypass: BYPASS_PHRASE in current prompt -> no block (counter unchanged).

import { readFileSync, existsSync } from 'fs';
import { join, dirname } from 'path';
import { homedir } from 'os';
import { fileURLToPath } from 'url';

const __dirname = dirname(fileURLToPath(import.meta.url));

export const THRESHOLD = 5;
export const RATE_WINDOW_MIN = 10;
export const RATE_THRESHOLD = 5;
export const BYPASS_PHRASE = 'лимит снят';

function loadVocab() {
  const vocabPath = join(__dirname, 'enforce-override-vocab.json');
  if (!existsSync(vocabPath)) return [];
  try {
    const j = JSON.parse(readFileSync(vocabPath, 'utf-8'));
    return Array.isArray(j.phrases) ? j.phrases.map(p => p.phrase) : [];
  } catch {
    return [];
  }
}

export const VOCAB = loadVocab();

export function findPhrasesInPrompt(prompt) {
  if (typeof prompt !== 'string' || !prompt) return [];
  const lower = prompt.toLowerCase();
  return VOCAB.filter(p => lower.includes(p.toLowerCase()));
}

export function countTodayUsage(rawLog, phrase, now = new Date()) {
  if (typeof rawLog !== 'string' || !rawLog) return 0;
  const today = now.toISOString().slice(0, 10);
  let count = 0;
  for (const line of rawLog.split('\n')) {
    if (!line) continue;
    try {
      const e = JSON.parse(line);
      if (e.phrase === phrase && typeof e.ts === 'string' && e.ts.slice(0, 10) === today) {
        count++;
      }
    } catch {
      // ignore malformed lines
    }
  }
  return count;
}


export function countWindowUsage(rawLog, phrase, now = new Date(), windowMinutes = 10) {
  if (typeof rawLog !== 'string' || !rawLog) return 0;
  const cutoffMs = now.getTime() - windowMinutes * 60_000;
  let count = 0;
  for (const line of rawLog.split('\n')) {
    if (!line) continue;
    try {
      const e = JSON.parse(line);
      if (e.phrase !== phrase) continue;
      if (typeof e.ts !== 'string') continue;
      const tsMs = Date.parse(e.ts);
      if (Number.isFinite(tsMs) && tsMs >= cutoffMs && tsMs <= now.getTime()) {
        count++;
      }
    } catch {
      // ignore malformed
    }
  }
  return count;
}

export function shouldBlock(prompt, rawLog, now = new Date()) {
  if (typeof prompt === 'string' && prompt.toLowerCase().includes(BYPASS_PHRASE.toLowerCase())) {
    return { block: false, bypass: true };
  }
  const phrases = findPhrasesInPrompt(prompt);
  for (const phrase of phrases) {
    const todayCount = countTodayUsage(rawLog, phrase, now);
    if (todayCount >= THRESHOLD) {
      return {
        block: true,
        phrase,
        todayCount,
        triggered: 'daily',
        reason: `daily count ${todayCount} >= ${THRESHOLD}`,
      };
    }
    const windowCount = countWindowUsage(rawLog, phrase, now, RATE_WINDOW_MIN);
    if (windowCount >= RATE_THRESHOLD) {
      return {
        block: true,
        phrase,
        windowCount,
        triggered: 'rate',
        reason: `rate-window count ${windowCount} >= ${RATE_THRESHOLD} in ${RATE_WINDOW_MIN} min`,
      };
    }
  }
  return { block: false };
}

export function buildBlockOutput({ phrase, todayCount, windowCount, triggered }) {
  if (triggered === 'rate') {
    return {
      decision: 'block',
      reason:
        `[enforce-override-limit] Override-фраза «${phrase}» использована ${windowCount} раз за последние ${RATE_WINDOW_MIN} минут (порог ${RATE_THRESHOLD}). ` +
        `Rate-spike обнаружен — это шаблонная привычка обхода, не реальная нужда. ` +
        `Сделай ПАУЗУ 10 минут перед следующим override, или вызови AskUserQuestion и попроси заказчика подтвердить новый bypass через «${BYPASS_PHRASE}» (счётчик НЕ сбрасывается).`,
    };
  }
  return {
    decision: 'block',
    reason:
      `[enforce-override-limit] Override-фраза «${phrase}» уже использована ${todayCount} раз сегодня (порог ${THRESHOLD}/день per phrase). ` +
      `Это 6-е или последующее использование — hard-block per Phase 2 plan. ` +
      `Чтобы продолжить, вызови AskUserQuestion и спроси заказчика явно. ` +
      `Если он подтверждает — следующий промпт должен содержать фразу «${BYPASS_PHRASE}» (one-shot bypass, счётчик НЕ сбрасывается).`,
  };
}

// CLI: read hook input from stdin, write block-JSON to stdout if needed.
async function main() {
  try {
    let raw = '';
    for await (const chunk of process.stdin) raw += chunk;
    let input;
    try { input = JSON.parse(raw || '{}'); } catch { input = {}; }

    // Find current user prompt - different hook payloads use different fields.
    const prompt =
      input?.prompt ||
      input?.hook_event?.prompt ||
      input?.user_prompt ||
      input?.transcript?.[input?.transcript?.length - 1]?.content ||
      '';

    const logPath = join(homedir(), '.claude', 'runtime', 'override-usage.jsonl');
    const rawLog = existsSync(logPath) ? readFileSync(logPath, 'utf-8') : '';

    const decision = shouldBlock(prompt, rawLog);
    if (decision.block) {
      process.stdout.write(JSON.stringify(buildBlockOutput(decision)));
      process.exit(0);
    }
    // No block - silent pass.
    process.exit(0);
  } catch {
    // Fail-open: any internal error must NOT block the user.
    process.exit(0);
  }
}

// Run as CLI if this file is the entrypoint (not when imported by tests).
const isCli = process.argv[1] && process.argv[1].replace(/\\/g, '/').endsWith('/enforce-override-limit.mjs');
if (isCli) main();