#!/usr/bin/env node
  // Hook: pre-compact-flush.mjs
  // Event: PreCompact (Claude Code v2.1.105+)
  // Purpose: Flush progress.json drift before context compaction so /ultraexecute-local
  --resume
  //          works after long conversations. Direct fix for the documented P0 in
  //          docs/ultraexecute-v2-observations-from-config-audit-v4.md.
  //
  // Behavior:
  //   1. Locate {cwd}/.claude/projects/* / progress.json (any nested project)
  //   2. Read progress.json + sibling plan.md
  //   3. Run `git log --oneline {session_start_sha}..HEAD`
  //   4. For each commit, match against plan steps' commit_message_pattern
  //   5. If derived current_step > stored current_step → write fresh checkpoint
  //      atomically (tmp + rename), monotonic only (current_step never decreases).
  //   6. Always exit 0 — NEVER blocks compaction.

  import { readFileSync, writeFileSync, renameSync, existsSync, readdirSync, statSync } from
   'node:fs';
  import { join, dirname } from 'node:path';
  import { execSync } from 'node:child_process';
  import { fileURLToPath } from 'node:url';

  const HERE = dirname(fileURLToPath(import.meta.url));
  const PLUGIN_ROOT = join(HERE, '..', '..');

  function findProgressFiles(cwd) {
    const projectsDir = join(cwd, '.claude', 'projects');
    if (!existsSync(projectsDir) || !statSync(projectsDir).isDirectory()) return [];
    const out = [];
    for (const entry of readdirSync(projectsDir)) {
      const projDir = join(projectsDir, entry);
      if (!statSync(projDir).isDirectory()) continue;
      const progPath = join(projDir, 'progress.json');
      if (existsSync(progPath) && statSync(progPath).isFile()) {
        out.push({ projDir, progPath, planPath: join(projDir, 'plan.md') });
      }
    }
    return out;
  }

  function readJson(path) {
    try { return JSON.parse(readFileSync(path, 'utf-8')); }
    catch { return null; }
  }

  function readPlanCheckpointPatterns(planPath) {
    if (!existsSync(planPath)) return new Map();
    const text = readFileSync(planPath, 'utf-8');
    const map = new Map();
    const stepRe = /^### Step (\d+):/gm;
    const checkpointRe = /\*\*Checkpoint:\*\*\s+`git commit -m "([^"]+)"`/;
    const headings = [];
    let m;
    while ((m = stepRe.exec(text)) !== null) {
      headings.push({ n: Number.parseInt(m[1], 10), idx: m.index });
    }
    for (let i = 0; i < headings.length; i++) {
      const start = headings[i].idx;
      const end = i + 1 < headings.length ? headings[i + 1].idx : text.length;
      const body = text.slice(start, end);
      const cp = body.match(checkpointRe);
      if (cp) {
        const msg = cp[1];
        const conventionalPrefix = (msg.match(/^([a-z]+)\(([^)]+)\):/) || [])[0];
        if (conventionalPrefix) map.set(headings[i].n, conventionalPrefix);
      }
    }
    return map;
  }

  function gitLog(repoDir, baseSha) {
    if (!baseSha) return [];
    try {
      const out = execSync(`git -C "${repoDir}" log --pretty=format:'%H %s' ${baseSha}..HEAD
   2>/dev/null`, {
        encoding: 'utf-8', timeout: 5000,
      });
      return out.trim().split('\n').filter(Boolean).map(line => {
        const sp = line.indexOf(' ');
        return { sha: line.slice(0, sp), subject: line.slice(sp + 1) };
      });
    } catch { return []; }
  }

  function deriveCurrentStep(progress, plan, gitCommits) {
    if (!progress || !progress.steps || gitCommits.length === 0) return null;
    const stored = progress.current_step || 0;
    let highestMatched = stored;
    for (const [stepN, prefix] of plan.entries()) {
      const matchedCommit = gitCommits.find(c => c.subject.startsWith(prefix.replace(/\\/g,
  '')));
      if (matchedCommit && stepN > highestMatched) highestMatched = stepN;
    }
    return highestMatched;
  }

  function atomicWrite(path, obj) {
    const tmp = path + '.tmp';
    writeFileSync(tmp, JSON.stringify(obj, null, 2));
    renameSync(tmp, path);
  }

  function repoRootOf(dir) {
    try {
      return execSync(`git -C "${dir}" rev-parse --show-toplevel 2>/dev/null`, { encoding:
  'utf-8', timeout: 2000 }).trim();
    } catch { return null; }
  }

  let stdinPayload = '';
  try { stdinPayload = readFileSync(0, 'utf-8'); } catch { /* fine */ }

  const cwd = process.env.CLAUDE_PROJECT_DIR || process.cwd();
  const progressFiles = findProgressFiles(cwd);

  if (progressFiles.length === 0) {
    process.exit(0);
  }

  let mutationsMade = 0;
  for (const { projDir, progPath, planPath } of progressFiles) {
    const progress = readJson(progPath);
    if (!progress || progress.status === 'completed') continue;

    const repoRoot = repoRootOf(projDir);
    if (!repoRoot) continue;

    const plan = readPlanCheckpointPatterns(planPath);
    if (plan.size === 0) continue;

    const sessionStart = progress.session_start_sha;
    if (!sessionStart) continue;

    const commits = gitLog(repoRoot, sessionStart);
    const derivedStep = deriveCurrentStep(progress, plan, commits);

    if (derivedStep !== null && derivedStep > (progress.current_step || 0)) {
      progress.current_step = derivedStep;
      progress.updated_at = new Date().toISOString();
      if (!progress.steps[String(derivedStep)]) {
        progress.steps[String(derivedStep)] = {
          status: 'completed', attempts: 1, error: null,
          completed_at: progress.updated_at, commit: null, manifest_audit: 'n/a',
          note: 'reconstructed by pre-compact-flush from git log',
        };
      }
      atomicWrite(progPath, progress);
      process.stderr.write(`[ultraplan-local] pre-compact flush: ${progPath} →
  current_step=${derivedStep}\n`);
      mutationsMade++;
    }
  }

  process.exit(0);