// hooks/lib/post-edit.mjs
// Shared by the post-edit guard (P7, hooks/scripts/post-edit-check.mjs) and
// the step check (K9, lib/verification/step-check.mjs): when the guard is on,
// and where its log lives.
//
// On (operator decision 06.10): while Voyage executes a plan in the repo -- a
// `.claude/projects/*/progress.json` (or legacy `.trekexecute-progress-*.json`)
// with status "in_progress" -- or when the repo has switched it on with
// `.claude/voyage-guards.json` = { "post_edit_check": true }. Off everywhere
// else, because the guard is wired for every session in every repo.

import { existsSync, readFileSync, readdirSync, mkdirSync, appendFileSync } from 'node:fs';
import { join } from 'node:path';

export const OPT_IN_FILE = join('.claude', 'voyage-guards.json');

function readJson(p) {
  try { return JSON.parse(readFileSync(p, 'utf8')); } catch { return null; }
}

function inProgress(p) {
  return readJson(p)?.status === 'in_progress';
}

export function executingPlan(root) {
  const projects = join(root, '.claude', 'projects');
  try {
    for (const d of readdirSync(projects, { withFileTypes: true })) {
      if (d.isDirectory() && inProgress(join(projects, d.name, 'progress.json'))) return true;
    }
  } catch { /* no projects dir */ }
  try {
    for (const f of readdirSync(root)) {
      if (/^\.trekexecute-progress-.+\.json$/.test(f) && inProgress(join(root, f))) return true;
    }
  } catch { /* unreadable root */ }
  return false;
}

export function optedIn(root) {
  const p = join(root, OPT_IN_FILE);
  return existsSync(p) && readJson(p)?.post_edit_check === true;
}

/** @returns {'plan'|'opt-in'|null} why the guard is on, or null when it is off */
export function postEditActive(root) {
  if (optedIn(root)) return 'opt-in';
  if (executingPlan(root)) return 'plan';
  return null;
}

export function postEditLogPath(gitDir) {
  return join(gitDir, 'voyage', 'post-edit.jsonl');
}

export function appendPostEditLog(gitDir, record) {
  const p = postEditLogPath(gitDir);
  mkdirSync(join(gitDir, 'voyage'), { recursive: true });
  appendFileSync(p, JSON.stringify(record) + '\n');
  return p;
}

// The latest record per file (repo-relative path).
export function latestPostEditRecords(gitDir) {
  const p = postEditLogPath(gitDir);
  const out = new Map();
  if (!existsSync(p)) return out;
  for (const line of readFileSync(p, 'utf8').split('\n')) {
    if (!line.trim()) continue;
    try {
      const r = JSON.parse(line);
      if (r && typeof r.file === 'string') out.set(r.file, r);
    } catch { /* a torn line is skipped, never read as clean */ }
  }
  return out;
}