#!/usr/bin/env node
// Hook: post-approval-log.mjs
// Event: PostToolUse (Bash, ExitPlanMode)
// Purpose: write an approval a person gave through Claude Code's prompt into
//   the approval log (contract K2, lib/util/approval-log.mjs).
//   - Bash: the call ran, so the ask from pre-bash-executor.mjs was approved.
//     What is logged is the record that hook wrote of what the person was
//     asked (hooks/lib/approval-record.mjs); no record, nothing logged.
//     Merge/push to main is logged as `merge`, tag/publish as `release`, each
//     with `--expires` (APPROVAL_TTL_MS). Push of other branches and
//     destructive git are not logged (operator decision 06.10). In
//     bypassPermissions mode nothing is logged: no person was asked.
//     sha256 binds the approval to the command and the commit it left HEAD on.
//   - ExitPlanMode: the person approved a plan. A Voyage plan (it carries
//     `plan_version`) is logged as `plan`, bound to the sha256 of the approved
//     text (`tool_response.plan`, hooks reference section ExitPlanMode).
// The guard never blocks (PostToolUse cannot), and it is never silent about a
// lost approval: when K2 is missing, refuses (1) or cannot run (2), Claude is
// told "not logged".

import { readFileSync } from 'node:fs';
import { createHash } from 'node:crypto';
import { spawnSync } from 'node:child_process';
import { APPROVAL_TTL_MS } from '../lib/git-approval.mjs';
import { takeApprovalRecord } from '../lib/approval-record.mjs';
import { runContract, isVoyagePlan } from '../lib/contract-cli.mjs';

const sha256 = (s) => createHash('sha256').update(s).digest('hex');

function say(text) {
  process.stdout.write(JSON.stringify({ hookSpecificOutput: { hookEventName: 'PostToolUse', additionalContext: text } }));
}

function headOf(cwd) {
  const r = spawnSync('git', ['rev-parse', 'HEAD'], { cwd, encoding: 'utf8', timeout: 10_000 });
  return r.status === 0 ? r.stdout.trim() : '';
}

function append(kind, subject, hash, cwd, expires) {
  const args = ['append', '--kind', kind, '--subject', subject, '--sha256', hash];
  if (expires) args.push('--expires', expires);
  const r = runContract('K2', args, { cwd });
  if (!r.ran) return `${kind} approval not logged: ${r.why}`;
  if (r.code === 0) return `${kind} approval logged${expires ? ` (expires ${expires})` : ''}`;
  const why = (r.stderr || r.stdout).trim().split('\n')[0] || `exit ${r.code}`;
  return `${kind} approval not logged: the approval log ${r.code === 1 ? 'refused it' : 'could not run'} (${why})`;
}

let input;
try {
  input = JSON.parse(readFileSync(0, 'utf-8'));
} catch {
  process.exit(0);
}

const cwd = input?.cwd || process.cwd();

if (input?.tool_name === 'ExitPlanMode') {
  const plan = input?.tool_response?.plan ?? input?.tool_input?.plan;
  if (!isVoyagePlan(plan)) process.exit(0);
  const subject = input?.tool_response?.filePath || input?.tool_input?.planFilePath || '(plan without a file path)';
  say(`[voyage] ${append('plan', subject, sha256(plan), cwd)}.`);
  process.exit(0);
}

if (input?.tool_name === 'Bash') {
  // Log what the person was asked (pre-bash-executor.mjs wrote it), nothing else.
  const rec = takeApprovalRecord(input?.session_id, input?.tool_use_id);
  const matches = (rec?.matches || []).filter((m) => m.kind);
  if (matches.length === 0) process.exit(0);
  if (rec.permission_mode === 'bypassPermissions') {
    say('[voyage] approval not logged: the session runs in bypassPermissions mode, so no person was asked.');
    process.exit(0);
  }
  const expires = new Date(Date.now() + APPROVAL_TTL_MS).toISOString();
  const seen = new Set();
  const notes = [];
  for (const m of matches) {
    const key = `${m.kind}\n${m.subject}`;
    if (seen.has(key)) continue;
    seen.add(key);
    const subject = m.subject || cwd;
    const hash = sha256(`${rec.command}\n${headOf(subject)}`);
    notes.push(append(m.kind, subject, hash, cwd, expires));
  }
  say(`[voyage] ${notes.join('; ')}.`);
}

process.exit(0);