#!/usr/bin/env node
/**
 * Default pretest gate: when `docs/audit/holepunch-drift-repos.json` lists repos, ensure
 * local clones under `BARE_OS_HOLEPUNCH_CLONES_ROOT` are not behind `origin/main`.
 * Disable with `BARE_OS_HOLEPUNCH_DRIFT_CHECK=0` (offline / no clones).
 *
 * Optional maintainer gate: `BARE_OS_HOLEPUNCH_DRIFT_TIER1=1` checks **`tier1Repos[]`**
 * from the same JSON (ignores **`repos[]`**), for a small Holepunch spine set.
 *
 * Prereq: `git fetch origin main` in each clone so origin/main is meaningful.
 * Config: docs/audit/holepunch-drift-repos.json → { repos: ["name", ...] }
 * Clones root: BARE_OS_HOLEPUNCH_CLONES_ROOT (same default as sync-holepunch-clones.mjs)
 */
import fs from 'node:fs'
import path from 'node:path'
import process from 'node:process'
import { fileURLToPath } from 'node:url'
import { execSync } from 'node:child_process'

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..')
const configPath = path.join(root, 'docs/audit/holepunch-drift-repos.json')

const defaultClones = path.join(
  process.env.HOME || '',
  'dev/pearcli/holepunch-repos/holepunchto_repos'
)
const clonesRoot = String(
  process.env.BARE_OS_HOLEPUNCH_CLONES_ROOT || defaultClones
).trim()

function gitOk(cmd, cwd) {
  try {
    execSync(cmd, {
      cwd,
      encoding: 'utf8',
      stdio: ['ignore', 'pipe', 'ignore']
    })
    return true
  } catch {
    return false
  }
}

/** @param {string} dir */
function gitCommitsBehindOriginMain(dir) {
  try {
    const o = execSync('git rev-list --count HEAD..origin/main', {
      cwd: dir,
      encoding: 'utf8',
      stdio: ['ignore', 'pipe', 'ignore']
    }).trim()
    const n = Number.parseInt(o, 10)
    return Number.isFinite(n) ? n : -1
  } catch {
    return -1
  }
}

function main() {
  const off =
    process.env.BARE_OS_HOLEPUNCH_DRIFT_CHECK === '0' ||
    process.env.BARE_OS_HOLEPUNCH_DRIFT_CHECK === 'false'
  if (off) {
    console.log(
      'verify-holepunch-clone-drift: skip (BARE_OS_HOLEPUNCH_DRIFT_CHECK=0)'
    )
    return
  }
  if (!fs.existsSync(configPath)) {
    console.error('verify-holepunch-clone-drift: missing', configPath)
    process.exit(1)
  }
  let cfg
  try {
    cfg = JSON.parse(fs.readFileSync(configPath, 'utf8'))
  } catch (e) {
    console.error('verify-holepunch-clone-drift: parse config failed', e)
    process.exit(1)
  }
  const tier1 =
    process.env.BARE_OS_HOLEPUNCH_DRIFT_TIER1 === '1' ||
    process.env.BARE_OS_HOLEPUNCH_DRIFT_TIER1 === 'true'
  let repos = Array.isArray(cfg.repos)
    ? cfg.repos.map((r) => String(r).trim()).filter(Boolean)
    : []
  if (tier1) {
    repos = Array.isArray(cfg.tier1Repos)
      ? cfg.tier1Repos.map((r) => String(r).trim()).filter(Boolean)
      : []
    if (!repos.length) {
      console.log(
        'verify-holepunch-clone-drift: tier1 mode but tier1Repos[] empty — nothing to check'
      )
      return
    }
    console.log(
      'verify-holepunch-clone-drift: tier1 mode — checking',
      repos.length,
      'repo(s)'
    )
  } else if (!repos.length) {
    console.log('verify-holepunch-clone-drift: repos[] empty — nothing to check')
    return
  }
  let failed = false
  /** @type {{ name: string, commitsBehind: number }[]} */
  const behindReport = []
  for (const name of repos) {
    const dir = path.join(clonesRoot, name)
    if (!fs.existsSync(dir)) {
      console.warn(
        'verify-holepunch-clone-drift: skip missing clone',
        path.relative(root, dir)
      )
      continue
    }
    if (!gitOk('git rev-parse --git-dir', dir)) {
      console.warn('verify-holepunch-clone-drift: skip non-git', name)
      continue
    }
    const hasOriginMain = gitOk('git rev-parse --verify origin/main', dir)
    if (!hasOriginMain) {
      console.warn(
        'verify-holepunch-clone-drift: no origin/main in',
        name,
        '(run git fetch origin main)'
      )
      continue
    }
    const upToDate = gitOk(
      'git merge-base --is-ancestor origin/main HEAD',
      dir
    )
    if (!upToDate) {
      const commitsBehind = gitCommitsBehindOriginMain(dir)
      behindReport.push({ name, commitsBehind })
      console.error(
        'verify-holepunch-clone-drift: clone is behind origin/main:',
        name,
        commitsBehind >= 0 ? `(~${commitsBehind} commits behind)` : ''
      )
      failed = true
    }
  }
  if (failed) {
    behindReport.sort((a, b) => b.commitsBehind - a.commitsBehind)
    const top = behindReport.slice(0, 12)
    console.error(
      'verify-holepunch-clone-drift: repos most behind origin/main (actionable PR order):'
    )
    for (const r of top) {
      console.error(
        `  - ${r.name}: ~${r.commitsBehind >= 0 ? r.commitsBehind : '?'} commits`
      )
    }
    console.error(
      'verify-holepunch-clone-drift: cross-check lockfile vs clones: node scripts/report-holepunch-lockfile-drift.mjs'
    )
    console.error(
      'verify-holepunch-clone-drift: FAIL — pull or fetch listed clones, or trim docs/audit/holepunch-drift-repos.json (see handbook ch.7 / scripts/release-checklist.mjs)'
    )
    process.exit(1)
  }
  const writeReport =
    process.env.BARE_OS_HOLEPUNCH_DRIFT_WRITE_REPORT === '1' ||
    process.env.BARE_OS_HOLEPUNCH_DRIFT_WRITE_REPORT === 'true'
  if (writeReport) {
    const outMd = path.join(root, 'docs/audit/holepunch-drift-last-run.md')
    const lines = [
      '# Holepunch clone drift (last verify)',
      '',
      `Generated: ${new Date().toISOString()}`,
      '',
      'All listed clones were at or ahead of `origin/main` when this file was written.',
      '',
      `Mode: ${tier1 ? 'tier1Repos[]' : 'repos[]'}`,
      '',
      'Repos checked:',
      ...repos.map((n) => `- ${n}`),
      '',
      'Re-run: `BARE_OS_HOLEPUNCH_DRIFT_WRITE_REPORT=1 npm run pretest` (or run this script directly after `git fetch`).',
      ''
    ]
    try {
      fs.mkdirSync(path.dirname(outMd), { recursive: true })
      fs.writeFileSync(outMd, lines.join('\n'), 'utf8')
    } catch (e) {
      console.warn('verify-holepunch-clone-drift: could not write report', e)
    }
  }
  console.log('verify-holepunch-clone-drift: OK')
}

main()