#!/usr/bin/env node
/**
 * Engagement trigger manifest — the machine-readable freeze of core's event
 * contract (ENGAGEMENT.md §4.3, property 4).
 *
 * Why this exists: a trigger declaration is what a template interpolates and what
 * a rule is written against. Renaming a variable, changing its type, or widening
 * a ceiling breaks stored templates and stored rules — and does it silently, at
 * send time, in an email someone already received. `routes.manifest.json` freezes
 * the URL surface for exactly this reason and this is its twin: a generated
 * artifact committed to the repo, whose DIFF is the review signal. Changing a
 * declaration without regenerating is a red build; changing one deliberately puts
 * the change in front of a reviewer instead of letting it pass as a comment edit.
 *
 * **Core's only.** A module ships its own `engagement-triggers.json` in its
 * bundle, for the same reason it ships a prebuilt swagger fragment: core never
 * has its sources to analyse (MODULE_API.md §6.1a). So this loads
 * `config/coreTriggers.js` through the real `registerCore()` — the declarations
 * as VALIDATED, not as authored — which means a shape error is a failure here
 * rather than a surprise at boot.
 *
 * The `resolve` half of an audience cannot be frozen (it is a function over a
 * module's own store), so audiences are deliberately absent: what a manifest can
 * usefully freeze is the payload contract, and freezing half a declaration would
 * suggest the other half was checked.
 *
 * Usage:
 *   npm run engagement:manifest            # write server/engagement-triggers.json
 *   npm run engagement:manifest -- --check # exit 1 if the committed file is stale
 */

// registries.js -> config/coreStreams + utils/discordAnnounce, which reach
// utils/db and build a mariadb pool at require time. Point it at a closed port
// (the same trick routeManifest.js and the test suite use) so generating a
// manifest never opens a connection or hangs on a missing database.
process.env.DB_HOST = process.env.DB_HOST || '127.0.0.1'
process.env.DB_PORT = process.env.DB_PORT || '59999'

const fs = require('fs')
const path = require('path')

const registries = require('../src/modules/registries')
const db = require('../src/utils/db')
const { MODULE_API_VERSION } = require('../src/modules/version')

const SERVER_ROOT = path.join(__dirname, '..')
const MANIFEST_PATH = path.join(SERVER_ROOT, 'engagement-triggers.json')

const MANIFEST_COMMENT =
  'Generated event-trigger inventory - the authoritative freeze of CORE\'s engagement ' +
  'contract (docs/website/ENGAGEMENT.md 4.3). Regenerate with `npm run engagement:manifest` ' +
  'in website/server. A renamed variable, a changed type or a widened ceiling breaks stored ' +
  'templates and rules, so the diff here is the review signal. A module ships its own copy ' +
  'in its bundle; this file never contains one.'

function build() {
  // Through registerCore(), not by reading the array: what a reviewer needs
  // frozen is what the registry ACCEPTED — defaults filled in, audience resolved
  // against the ceiling, variables normalised — because that is what the editor
  // will read and the emit path will check against.
  registries.registerCore()

  const triggers = registries
    .allTriggers()
    .filter((t) => t.owner === 'core')
    // Sorted by id rather than left in registration order, like the route
    // manifest: reordering a declaration in the source is not a contract change
    // and must not produce a diff that looks like one.
    .sort((a, b) => a.id.localeCompare(b.id))
    .map((t) => ({
      id: t.id,
      owner: t.owner,
      label: t.label,
      description: t.description,
      kind: t.kind,
      subjectKey: t.subjectKey,
      audience: t.audience,
      ceiling: t.ceiling,
      version: t.version,
      // Variables keep their DECLARED order. Here it is contract: it is the
      // order the template editor lists them in, and an author reading the
      // manifest should see what the editor will show.
      variables: t.variables.map((v) => ({
        name: v.name,
        type: v.type,
        required: v.required,
        example: v.example,
        description: v.description,
      })),
    }))

  return {
    _comment: MANIFEST_COMMENT,
    // The contract version these declarations are shaped by. A reader looking at
    // a stale manifest needs to know which API's rules produced it.
    moduleApiVersion: MODULE_API_VERSION,
    triggers,
  }
}

function main() {
  const check = process.argv.includes('--check')
  const next = `${JSON.stringify(build(), null, 2)}\n`

  if (!check) {
    fs.writeFileSync(MANIFEST_PATH, next)
    process.stdout.write(`wrote ${path.relative(SERVER_ROOT, MANIFEST_PATH)}\n`)
    return
  }

  const current = fs.existsSync(MANIFEST_PATH) ? fs.readFileSync(MANIFEST_PATH, 'utf8') : ''
  if (current === next) {
    process.stdout.write('engagement-triggers.json is current\n')
    return
  }
  process.stderr.write(
    'engagement-triggers.json is stale.\n' +
      'A trigger declaration changed without the manifest being regenerated.\n' +
      'Run `npm run engagement:manifest` in website/server and commit the result —\n' +
      'the diff is what a reviewer reads to see the contract change.\n',
  )
  process.exitCode = 1
}

if (require.main === module) {
  main()
  // The mariadb pool never connects here, but it keeps the loop alive even
  // pointed at a dead port — the same exit routeManifest.js takes.
  db.close().finally(() => process.exit(process.exitCode || 0))
}

module.exports = { build }