#!/usr/bin/env node
//
// The engagement freeze: every trigger, stream and audience this module
// declares, and every rule it seeds, as one committed file whose DIFF is the
// review signal (MODULE_API.md §2.4: "a module ships a prebuilt
// `engagement-triggers.json` in its bundle").
//
// **Why it exists when core never reads it.** A trigger declaration is what an
// operator's templates interpolate and their rules are written against.
// Renaming a variable, changing its type or widening a ceiling breaks stored
// templates and rules — silently, at send time, in a mail somebody already
// got. Committing the declarations as data turns that edit into a visible diff
// in the PR that makes it, the same job `routes.manifest.json` does for URLs.
//
// **It is generated from the registrations, not from the source files**, by
// running `register()` against a recording api — so what is frozen is what core
// would be handed, including anything `index.js` does on the way.
//
// **It records `coreApi`, not core's `MODULE_API_VERSION`.** Core's own manifest
// embeds the API version, and every API bump then makes it stale with no change
// to a single declaration — which is how it once sat stale for a whole phase.
// The range this module declares moves only when this module decides it should.
//
// Usage (from server/):
//   node scripts/engagementManifest.js          write ../engagement-triggers.json
//   node scripts/engagementManifest.js --check  exit 1 if the committed file is stale

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

const { fakeCtx, fakeApi } = require('../test/_fakes')

const MODULE_ROOT = path.resolve(__dirname, '..', '..')
const MANIFEST = path.join(MODULE_ROOT, 'engagement-triggers.json')

const COMMENT =
  'Generated freeze of module-rust\'s engagement contract (docs/modules/rust/PLAN.md §25). ' +
  'Regenerate with `npm run engagement:manifest` in server/. A renamed variable, a changed type ' +
  'or a widened ceiling breaks stored templates and rules, so the diff here is the review signal.'

function build() {
  require('../core')._reset()
  const api = fakeApi()
  require('../index')(fakeCtx(), api)
  const { triggers, streams, audiences, engagementSeeds } = api.record
  const manifest = require('../../module.json')

  const byId = (a, b) => a.id.localeCompare(b.id)

  return {
    _comment: COMMENT,
    coreApi: manifest.coreApi,
    // Sorted by id: reordering a declaration in the source is not a contract
    // change and must not produce a diff that looks like one. Variables keep
    // their DECLARED order, which is the order the template editor shows.
    triggers: [...triggers].sort(byId).map((t) => ({
      id: t.id,
      label: t.label,
      description: t.description,
      kind: t.kind,
      subjectKey: t.subjectKey,
      audience: t.audience,
      ceiling: t.ceiling,
      version: t.version,
      variables: t.variables.map((v) => ({
        name: v.name,
        type: v.type,
        required: v.required,
        example: v.example,
        description: v.description,
      })),
    })),
    streams: [...streams].sort(byId).map((s) => ({
      id: s.id,
      label: s.label,
      personal: s.personal,
      requiresLinkedAccount: s.requiresLinkedAccount,
    })),
    // `resolve` is a function over this module's store and cannot be frozen.
    // What is frozen is the part an operator's saved rule depends on.
    audiences: [...audiences].sort(byId).map((a) => ({
      id: a.id,
      label: a.label,
      params: a.params,
      ceiling: a.ceiling,
    })),
    ruleGroups: engagementSeeds.ruleGroups.map((g) => ({
      key: g.key,
      rules: g.rules.map((r) => ({
        trigger_id: r.trigger_id,
        audience: r.audience,
        channels: r.channels,
        template_keys: r.template_keys,
        conditions: r.conditions === undefined ? null : r.conditions,
        cooldown_seconds: r.cooldown_seconds,
        delay_seconds: r.delay_seconds || 0,
        cancel_on: r.cancel_on || [],
      })),
    })),
    templates: engagementSeeds.templates.map((t) => ({
      key: t.key,
      channel: t.channel,
      triggerId: t.triggerId,
      seedVersion: t.seedVersion,
    })),
  }
}

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

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

  // Line endings normalised, as `swaggerFragment.js` does: a Windows checkout
  // under `core.autocrlf=true` turns the committed LF blob into CRLF, and a byte
  // comparison would then call an unchanged file stale on every such machine —
  // a check that cries wolf is a check nobody reads.
  const lf = (s) => s.replace(/\r\n/g, '\n')
  let committed
  try {
    committed = fs.readFileSync(MANIFEST, 'utf8')
  } catch {
    process.stderr.write('engagement-triggers.json is missing — run `npm run engagement:manifest`\n')
    process.exit(1)
  }

  if (lf(committed) !== lf(next)) {
    process.stderr.write(
      'engagement-triggers.json is stale: a trigger, stream, audience or seeded rule changed.\n' +
      'Run `npm run engagement:manifest` in server/ and commit the result — and read the diff,\n' +
      'because a changed variable or ceiling is a change to every rule an operator has saved.\n',
    )
    process.exit(1)
  }

  process.stdout.write('engagement-triggers.json is current\n')
}

if (require.main === module) main()

module.exports = { build }