// Conventional Commits lint (prek commit-msg stage): reject a commit whose
// header is not a Conventional Commit. Read-only — version bumping happens at
// release time (scripts/version-bump.mjs), not per commit, so parallel
// worktrees stop contending on package.json and the manifest.
import { readFileSync } from 'node:fs'
import { GIT_SHAPES, HEADER, TYPES } from './conventional.mjs'

const SCISSORS = '# ------------------------ >8 ------------------------'

const msgFile = process.argv[2]
if (!msgFile) {
  console.error('usage: lint-commit-msg.mjs <commit-msg-file>')
  process.exit(2)
}

// Keep the message above the scissors line (git commit -v appends the diff
// below one) and drop comment lines before looking for the header.
const raw = readFileSync(msgFile, 'utf8')
const cut = raw.indexOf(SCISSORS)
const lines = (cut === -1 ? raw : raw.slice(0, cut))
  .split('\n')
  .filter((line) => !line.startsWith('#'))
const header = lines.find((line) => line.trim() !== '') ?? ''

if (GIT_SHAPES.test(header)) process.exit(0)

if (!HEADER.test(header)) {
  console.error(`commit-lint: not a Conventional Commit header: "${header}"`)
  console.error(`commit-lint: expected "<type>(<scope>)!?: <description>" with a type in: ${TYPES.join(', ')}`)
  process.exit(1)
}