// ── The email channel on the engine (ENGAGEMENT.md Phase 6) ────────────────
//
// The phase's own acceptance criteria, plus the four things building it showed
// were worth pinning:
//
//   • a scoped preference is what decides a Team-scoped event, and it REPLACES
//     the stream-level one — intersecting would silence every existing subscriber
//   • the structural projection fills only what the payload did not
//   • a `members` audience resolves to the set the EVENT carried
//   • core's four seeded rules exist, are all disabled, and are seeded once
//
// Point the DB at a closed port before requiring anything: the registries reach
// utils/discordAnnounce, which builds the pool at require time.
process.env.DB_HOST = '127.0.0.1'
process.env.DB_PORT = '59999'

const { test, beforeEach, afterEach, after } = require('node:test')
const assert = require('node:assert/strict')

const registries = require('../src/modules/registries')
const channels = require('../src/engagement/channels')
const scopedPrefs = require('../src/engagement/scopedPrefs')
const projection = require('../src/engagement/projection')
const audiences = require('../src/engagement/audiences')
const engine = require('../src/engagement/engine')
const emailChannel = require('../src/engagement/emailChannel')
const coreRules = require('../src/engagement/coreRules')
const templates = require('../src/engagement/templates')
const mailer = require('../src/utils/mailer')
const unsubscribeToken = require('../src/utils/unsubscribeToken')
const engagementEmit = require('../src/utils/engagementEmit')
const rulesDb = require('../src/model/engagement/engagementRules.db')
const recipients = require('../src/model/engagement/engagementRecipients.db')
const settingsDb = require('../src/model/settings/settings.db')
const teamNotifyModel = require('../src/model/teams/teamNotify.model')
const unsubCtrl = require('../src/router/v1/public/engagement.controller')
const db = require('../src/utils/db')

// Requiring this is what registers core's channels, transports and the `team`
// scope provider — the one door (engagement/index.js's header). It does NOT
// register core's TRIGGERS: those come from `registries.registerCore()`, which
// app.js calls, and the split is deliberate — a trigger is a module-facing
// declaration and a channel is an internal sink.
require('../src/engagement')
registries.registerCore()

after(() => db.close())

const saved = new Map()
function patch(mod, name, fn) {
  if (!saved.has(mod)) saved.set(mod, new Map())
  if (!saved.get(mod).has(name)) saved.get(mod).set(name, mod[name])
  mod[name] = fn
}
function restore() {
  for (const [mod, names] of saved) for (const [name, fn] of names) mod[name] = fn
  saved.clear()
}

const TRIGGER = 'team.forum.post'

let world

beforeEach(() => {
  world = { mails: [], teamPrefs: new Map(), storedModes: new Map(), inserted: [], settings: new Map() }

  patch(mailer, 'sendNotification', async (msg) => {
    world.mails.push(msg)
    return { ok: true, transport: 'smtp' }
  })
  patch(templates, 'renderByKey', async (key, values) => ({
    subject: `[${key}] ${values.title || ''}`,
    html: '<p>x</p>',
    text: 'x',
    missing: [],
    values,
  }))
  patch(recipients, 'addressFor', async (userId) => ({ address: `u${userId}@example.test` }))
  patch(recipients, 'filterActive', async (ids) => ids)
  patch(recipients, 'storedModes', async () => world.storedModes)
  patch(teamNotifyModel, 'prefsForTeam', async (userIds, teamId) =>
    userIds
      .map((id) => world.teamPrefs.get(`${id}|${teamId}`))
      .filter(Boolean))
  patch(rulesDb, 'getById', async () => ({
    id: 1,
    trigger_id: TRIGGER,
    template_keys: { email: 'notify.team-post' },
  }))
})
afterEach(restore)

const outboxRow = (over = {}) => ({
  id: 1,
  rule_id: 1,
  trigger_id: TRIGGER,
  user_id: 11,
  channel: 'email',
  subject_key: 'The Silver Hand',
  scope_key: 'team:1',
  payload: { teamName: 'The Silver Hand', authorName: 'Ten', threadTitle: 'Raid', postUrl: '/g/1?thread=7' },
  ...over,
})

// ── deliver ────────────────────────────────────────────────────────────────

test('a delivered row renders its rule’s template and sends to the user’s address', async () => {
  const result = await emailChannel.deliver(outboxRow())
  assert.equal(result.ok, true)
  assert.equal(world.mails[0].to, 'u11@example.test')
  assert.match(world.mails[0].rendered.subject, /^\[notify\.team-post\]/)
})

test('a rule naming no template falls back to the generic one, which is what makes a new trigger mailable', async () => {
  patch(rulesDb, 'getById', async () => ({ id: 1, trigger_id: TRIGGER, template_keys: {} }))
  await emailChannel.deliver(outboxRow())
  assert.match(world.mails[0].rendered.subject, /^\[notify\.event\]/)
})

// Terminal, not retryable. Retrying does not give somebody an address, and a
// banned account will not be un-banned by a five-minute backoff.
test('a user with no deliverable address is a terminal failure, not a retry', async () => {
  patch(recipients, 'addressFor', async () => null)
  const result = await emailChannel.deliver(outboxRow())
  assert.equal(result.ok, false)
  assert.equal(result.retry, undefined)
  assert.equal(world.mails.length, 0)
})

// A throw would be read by the worker as a transient failure and retried five
// times, so an unrenderable template would become five identical rows in the send
// log instead of one honest terminal one.
test('deliver never throws — a render failure is classified, not propagated', async () => {
  patch(templates, 'renderByKey', async () => { throw new Error('blocks are broken') })
  const result = await emailChannel.deliver(outboxRow())
  assert.equal(result.ok, false)
  assert.match(result.detail, /blocks are broken/)
})

test('the send log gets a hash of the address and never the address', async () => {
  const result = await emailChannel.deliver(outboxRow())
  assert.match(result.addressHash, /^[0-9a-f]{64}$/)
  assert.equal(result.addressHash.includes('@'), false)
})

// A bounce arrives with an address, not with a spelling. Two spellings of one
// mailbox must hash to one row or the correlation Phase 9 needs cannot be made.
test('the address hash is case-folded, so a bounce can be correlated', async () => {
  const a = await emailChannel.deliver(outboxRow())
  patch(recipients, 'addressFor', async () => ({ address: '  U11@Example.Test ' }))
  const b = await emailChannel.deliver(outboxRow())
  assert.equal(a.addressHash, b.addressHash)
})

// ── The unsubscribe link ───────────────────────────────────────────────────

test('every mail carries both unsubscribe urls, and they are not the same url', async () => {
  await emailChannel.deliver(outboxRow())
  const { unsubscribeUrl, unsubscribeApiUrl } = world.mails[0]
  assert.notEqual(unsubscribeUrl, unsubscribeApiUrl)
  // The header one has to be an ENDPOINT — a one-click client POSTs to it without
  // rendering anything — and the body one has to be a page a human can read first.
  assert.match(unsubscribeApiUrl, /\/api\/v1\/public\/engagement\/unsubscribe\//)
  assert.match(unsubscribeUrl, /\/unsubscribe\//)
})

test('the link’s token names the email channel and the event’s SCOPE, not its subject', async () => {
  await emailChannel.deliver(outboxRow())
  const token = world.mails[0].unsubscribeApiUrl.split('/').pop()
  assert.deepEqual(unsubscribeToken.verify(token), {
    userId: 11, channel: 'email', scopeKey: 'team:1', version: 2,
  })
  // `subject_key` is the Team's NAME, which a rename changes. Signing over it
  // would orphan every link in a mailbox the first time staff renamed a guild.
  assert.equal(token.includes('Silver'), false)
})

test('a scope the token format cannot carry costs the link, not the mail', async () => {
  const result = await emailChannel.deliver(outboxRow({ scope_key: 'NOT A SCOPE' }))
  assert.equal(result.ok, true)
  assert.equal(world.mails[0].unsubscribeUrl, null)
})

// ── The projection (§4.6.1 property 1) ─────────────────────────────────────

test('the projection fills only what the payload left out', () => {
  const declaration = registries.eventTrigger(TRIGGER)
  assert.ok(declaration, 'core registers the four Team triggers')

  const values = projection.project(TRIGGER, { teamName: 'X', threadTitle: 'Raid', postUrl: '/g/1' })
  assert.equal(values.threadTitle, 'Raid')          // untouched
  assert.equal(values.title, declaration.label)     // supplied
  assert.equal(values.intro, declaration.description)
  assert.equal(values.actionUrl, '/g/1')            // the first declared url with a value
})

// `news.post` and `team.announcement` both declare their own `title`. A
// projection that overwrote it would replace a real headline with a category
// label — on the one variable every generic template puts in the subject line.
test('a payload that declares its own title keeps it', () => {
  const values = projection.project('team.announcement', { teamName: 'X', title: 'Siege moved' })
  assert.equal(values.title, 'Siege moved')
})

test('an unregistered trigger still renders from its snapshot rather than being refused', () => {
  const values = projection.project('gone.away', { title: 'kept' })
  assert.equal(values.title, 'kept')
  assert.deepEqual(values.items, [])
})

// ── The event-carried audience (decision 2) ────────────────────────────────

test('a members audience resolves to the recipient set the event carried', async () => {
  const resolved = await audiences.resolveForRule(
    { audience: 'members', audience_segment_id: null },
    { triggerId: TRIGGER, recipientUserIds: [11, 12] },
  )
  assert.deepEqual(resolved.userIds, [11, 12])
  assert.equal(resolved.ceiling, 'members')
  assert.equal(resolved.dormant, false)
})

test('a members audience with no carried set and no segment still reaches nobody', async () => {
  const resolved = await audiences.resolveForRule(
    { audience: 'members', audience_segment_id: null },
    { triggerId: TRIGGER },
  )
  assert.deepEqual(resolved.userIds, [])
  assert.match(resolved.reason, /needs a segment/)
})

// The carried set is a NARROWING input. It names who the event is about; it does
// not raise what a rule is allowed to reach.
test('a carried audience is still filtered for account status', async () => {
  patch(recipients, 'filterActive', async (ids) => ids.filter((id) => id !== 12))
  const resolved = await audiences.resolveForRule(
    { audience: 'members', audience_segment_id: null },
    { triggerId: TRIGGER, recipientUserIds: [11, 12] },
  )
  assert.deepEqual(resolved.userIds, [11])
})

test('and it is still under the trigger’s G24 ceiling', () => {
  // `members` is what the four Team triggers ceiling at, so a carried set can
  // never be given `authenticated` by a rule that names one.
  assert.equal(audiences.permitted(TRIGGER, 'members'), true)
  assert.equal(audiences.permitted(TRIGGER, 'authenticated'), false)
})

test('the emit contract refuses an audience that is not a list of user ids', () => {
  const bad = (recipientUserIds) =>
    assert.throws(() => engagementEmit.emit('core', TRIGGER, {
      data: { teamName: 'X', authorName: 'A', threadTitle: 'T' },
      recipientUserIds,
    }))
  bad('11')
  bad([0])
  bad([1.5])
  bad(new Array(6000).fill(1).map((_, i) => i + 1))
})

// ── Scoped preferences (decision 4) ────────────────────────────────────────

const teamPref = (userId, teamId, over) => world.teamPrefs.set(`${userId}|${teamId}`, {
  user_id: userId, muted: 0, email_mode: 'off', ...over,
})

test('a Team-scoped email event is decided by team_notification_prefs', async () => {
  teamPref(11, 1, { email_mode: 'immediate' })
  teamPref(12, 1, { email_mode: 'off' })
  const eligible = await engine.subscribedTo([11, 12], TRIGGER, 'email', 'team:1')
  assert.deepEqual(eligible, [11])
})

// **The heart of decision 4.** `notification_channel_prefs` holds a row only
// where a user expressed something, absence means the channel default, and
// email's is `off`. Nobody has ever expressed a stream-level opinion about a Team
// trigger — the screen that would let them is Phase 3's and the preference
// predates it. So intersecting the two would resolve every existing Team-email
// subscriber to `off` and silence the live pipeline on the migrating deploy.
test('the scoped preference REPLACES the stream one — it does not intersect with it', async () => {
  teamPref(11, 1, { email_mode: 'immediate' })
  world.storedModes = new Map() // no stream-level row: the state of every real user
  assert.equal(channels.defaultMode('email'), 'off')
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'email', 'team:1'), [11])
})

test('a per-Team mute silences every channel, not only the one that carries content', async () => {
  teamPref(11, 1, { muted: 1, email_mode: 'immediate' })
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'email', 'team:1'), [])
  world.storedModes = new Map([[11, 'instant']])
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'push', 'team:1'), [])
})

test('a scope says nothing about push, so the stream preference decides it', async () => {
  teamPref(11, 1, { email_mode: 'off' })
  world.storedModes = new Map([[11, 'instant']])
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'push', 'team:1'), [11])
})

test('an unscoped event is decided by the stream preference alone', async () => {
  teamPref(11, 1, { email_mode: 'immediate' })
  world.storedModes = new Map()
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'email', null), [])
})

// Fails OPEN, and the practical effect is that nothing is sent rather than that
// everybody is: the stream-level default is `off`. Failing closed would instead
// drop an unrelated IDOC warning because a Team preference query timed out.
test('a scope provider that throws leaves the stream preference in charge', async () => {
  patch(teamNotifyModel, 'prefsForTeam', async () => { throw new Error('db is on fire') })
  world.storedModes = new Map([[11, 'instant']])
  assert.deepEqual(await engine.subscribedTo([11], TRIGGER, 'email', 'team:1'), [11])
})

test('an unparseable or unclaimed scope is "no scope", never some other scope', async () => {
  assert.equal(scopedPrefs.parse('team:1').prefix, 'team')
  assert.equal(scopedPrefs.parse('team:'), null)
  assert.equal(scopedPrefs.parse(':1'), null)
  assert.equal(scopedPrefs.parse(''), null)
  assert.equal((await scopedPrefs.resolve([11], 'email', 'nosuch:1')).size, 0)
})

// ── The one-click unsubscribe (decision 7) ─────────────────────────────────

test('a v2 email token turns off that Team’s email and leaves its push alone', async () => {
  const writes = []
  patch(teamNotifyModel, 'setEmailMode', async (...a) => writes.push(['email', ...a]))
  patch(teamNotifyModel, 'mute', async (...a) => writes.push(['mute', ...a]))
  await unsubCtrl.applyClaim({ userId: 11, channel: 'email', scopeKey: 'team:1' })
  assert.deepEqual(writes, [['email', 11, 1, 'off']])
})

// The acceptance criterion: a link from a mail sent BEFORE the migration still
// works. It arrives at the old path, verifies as a v1 token, and turns off the
// email it was labelled as turning off.
test('a pre-migration link still unsubscribes, through the same handler', async () => {
  const writes = []
  patch(teamNotifyModel, 'setEmailMode', async (...a) => writes.push(a))
  const legacy = unsubscribeToken.signLegacy(11, 1)
  const res = { json: (body) => { res.body = body } }
  await unsubCtrl.unsubscribe({ params: { token: legacy } }, res)
  assert.deepEqual(res.body, { ok: true })
  assert.deepEqual(writes, [[11, 1, 'off']])
})

// An oracle for which (user, scope) pairs exist would be a real disclosure on an
// endpoint with no session behind it.
test('a forged token is answered exactly like a real one', async () => {
  const writes = []
  patch(teamNotifyModel, 'setEmailMode', async (...a) => writes.push(a))
  const res = { json: (body) => { res.body = body } }
  await unsubCtrl.unsubscribe({ params: { token: '2.11.email.team:1.AAAAAAAAAAAAAAAAAAAAAA' } }, res)
  assert.deepEqual(res.body, { ok: true })
  assert.deepEqual(writes, [])
})

test('a GET on the unsubscribe endpoint mutates nothing and lands on the page', () => {
  const writes = []
  patch(teamNotifyModel, 'setEmailMode', async (...a) => writes.push(a))
  let redirected = null
  unsubCtrl.unsubscribeLanding(
    { params: { token: unsubscribeToken.sign(11, 'email', 'team:1') } },
    { redirect: (code, url) => { redirected = { code, url } } },
  )
  assert.equal(redirected.code, 302)
  assert.match(redirected.url, /\/unsubscribe\//)
  assert.deepEqual(writes, [], 'a link scanner must not be able to unsubscribe anybody')
})

// ── The seeded rules (decision 3) ──────────────────────────────────────────

test('core seeds a rule for each Team trigger, and every one of them is OFF', async () => {
  patch(settingsDb, 'get', async () => null)
  patch(settingsDb, 'set', async (k, v) => world.settings.set(k, v))
  patch(rulesDb, 'insert', async (rule) => { world.inserted.push(rule); return world.inserted.length })

  const summary = await coreRules.seedTeamRules()
  assert.equal(summary.inserted, 4)
  assert.deepEqual(
    world.inserted.map((r) => r.trigger_id).sort(),
    ['team.announcement', 'team.forum.post', 'team.leadership.changed', 'team.member.joined'],
  )
  // The invariant the org lead chose to honour rather than carve an exception
  // into: nothing is seeded on. Team email resumes when an operator switches one
  // on, and the release note says so.
  assert.equal(world.inserted.every((r) => r.enabled === 0), true)
  // `members`, which is what resolves to the carried recipient set. Anything
  // wider would be refused by the trigger's own ceiling anyway.
  assert.equal(world.inserted.every((r) => r.audience === 'members'), true)
  assert.equal(world.inserted.every((r) => r.channels.includes('email')), true)
})

test('every seeded rule names a template that actually exists', () => {
  const seeded = new Set(coreRules.RULES.flatMap((r) => Object.values(r.template_keys)))
  const shipped = new Set(require('../src/engagement/templateSeeds').SEEDS.map((s) => s.key))
  for (const key of seeded) assert.equal(shipped.has(key), true, `${key} is not a shipped template`)
})

// Seeded once, not ensured: an operator who deletes a rule must not find it back
// after a restart, and one they enabled must not be reset to off.
test('a second boot seeds nothing', async () => {
  patch(settingsDb, 'get', async () => '2026-08-29T00:00:00.000Z')
  patch(rulesDb, 'insert', async () => { throw new Error('must not insert') })
  const summary = await coreRules.seedTeamRules()
  assert.equal(summary.inserted, 0)
  assert.equal(summary.skipped, 4)
})