// Test doubles for what core hands the module.
//
// The module's server half is testable WITHOUT core, and that is not a
// convenience — it is the contract holding. Everything the module may touch
// arrives on `ctx` (MODULE_API.md §2.3), so a `ctx` this file can build is a
// complete statement of the module's dependencies. If a test ever needs
// something that is not here, either the module reached past the boundary or
// §2.3 needs a member; both are worth stopping for.
//
// `fakeCtx` mirrors §2.3 member for member, including the freezing, so a module
// that assigns to `ctx.something` fails here the way it would in core.

const express = require('express')

/** Records every call, so a test can assert what a module asked for. */
function spy(returns) {
  const fn = (...args) => {
    fn.calls.push(args)
    return typeof returns === 'function' ? returns(...args) : returns
  }
  fn.calls = []
  return fn
}

function fakeLog() {
  const log = { error: spy(), warn: spy(), info: spy(), debug: spy() }
  return log
}

function fakeCtx(overrides = {}) {
  // `freeze: false` is for _setup.js, which installs one process-wide ctx a test
  // may adjust. Core always freezes; the unfrozen variant is a test seam and
  // never a claim about what a module is handed in production.
  const { freeze = true, ...rest } = overrides
  const logs = []
  const ctx = {
    moduleId: 'uo',
    paths: { moduleRoot: require('path').resolve(__dirname, '..', '..') },
    express,
    validator: require('express-validator'),
    db: { query: spy(Promise.resolve([])), pool: {} },
    log: (namespace) => {
      const log = fakeLog()
      logs.push({ namespace, log })
      return log
    },
    settings: { get: spy(Promise.resolve(null)), set: spy(Promise.resolve()), getInstanceName: spy(Promise.resolve('Test')) },
    auth: { getUserFromRequest: spy(null) },
    push: { publish: spy(Promise.resolve()) },
    // MODULE_API 1.7.0. Both are fire-and-forget and return undefined by
    // contract — a module gets no delivery answer back, deliberately — so the
    // spies return undefined rather than a promise, which is what core does.
    events: { emit: spy(undefined), reconcile: spy(undefined) },
    inbox: { push: spy(undefined) },
    secretBox: { encrypt: spy('enc'), decrypt: spy('dec') },
    middleware: {
      requireAuth: (req, res, next) => next(),
      requireRole: () => (req, res, next) => next(),
      siteMode: (req, res, next) => next(),
      validate: (req, res, next) => next(),
      noindex: (req, res, next) => next(),
      // API 1.1.0. The factory returns a pass-through rather than a real
      // limiter: a test that tripped a rate limit would be a test whose result
      // depended on how many times the suite had run.
      rateLimit: (options) => Object.assign((req, res, next) => next(), { options }),
      accountChangeLimiter: (req, res, next) => next(),
    },
    uploads: { upload: {}, UPLOAD_DIR: '/tmp', MIME_EXT: {} },
    posts: { listAll: spy(Promise.resolve([])), getById: spy(Promise.resolve(null)), linkAnnounceJob: spy(Promise.resolve()), markAnnounced: spy(Promise.resolve()) },
    // The three §2.3 members API 1.1.0 added for this extraction.
    activity: { log: spy(Promise.resolve()) },
    users: { getById: spy(Promise.resolve(null)) },
    site: { baseUrl: 'http://localhost:5173' },
    ...rest,
  }
  // Non-enumerable, and that is not tidiness. Core freezes every object value on
  // `ctx` one level deep, so an enumerable recorder hung off it would be frozen
  // by the loop below and every `log.info` call would throw on push — which is
  // how this was found. Keeping it off the enumeration also makes the fake more
  // faithful: a module iterating `ctx` sees exactly §2.3's members and nothing
  // a test put there.
  Object.defineProperty(ctx, 'logs', { value: logs, enumerable: false })
  if (!freeze) return ctx
  for (const value of Object.values(ctx)) {
    if (value && typeof value === 'object') Object.freeze(value)
  }
  return Object.freeze(ctx)
}

/**
 * The registration api, recording rather than mounting.
 *
 * Copies core's `once()` rule (§2.4: "calling twice is an error") because a
 * module that registers the same thing twice must fail in its own test suite
 * and not first on an operator's install.
 */
function fakeApi() {
  const record = {
    routes: null,
    extensions: [],
    streams: null,
    legs: [],
    teamProvider: null,
    slashCommands: [],
    triggers: null,
    audiences: null,
    eventActions: null,
    eventBudgets: null,
    eventOptionSources: null,
    hooks: {},
  }
  const called = new Set()
  const once = (name) => {
    if (called.has(name)) throw new Error(`${name}() called twice`)
    called.add(name)
  }
  const api = {
    registerRoutes(mounts) { once('registerRoutes'); record.routes = mounts },
    registerExtension(slot, router) { record.extensions.push({ slot, router }) },
    registerNotificationStreams(streams) { once('registerNotificationStreams'); record.streams = streams },
    registerAnnounceLeg(leg) { record.legs.push(leg) },
    // MODULE_API 1.6.0. `once` because core holds a single provider per
    // deployment — a second registration is a collision there, so it has to be
    // one here too, or this suite would pass a shape core rejects at load.
    registerTeamProvider(provider) { once('registerTeamProvider'); record.teamProvider = provider },
    // MODULE_API 1.6.0, live since phase 7. `once` for the same reason core
    // takes it: a second call is a module changing its mind halfway through
    // register(), which core rejects.
    registerSlashCommands(commands) { once('registerSlashCommands'); record.slashCommands = commands },
    // MODULE_API 1.7.0, live since ENGAGEMENT.md Phase 11. `once` on both, for
    // the reason above: core stages a registrant's whole batch and applies it as
    // one, so a second call is a module changing its mind mid-register().
    registerEventTriggers(triggers) { once('registerEventTriggers'); record.triggers = triggers },
    registerAudiences(audiences) { once('registerAudiences'); record.audiences = audiences },
    // MODULE_API 1.9.0 (ENGAGEMENT.md Phase 11b). `once` again, and here it is
    // load-bearing rather than tidy: a rule belongs to exactly ONE named group,
    // and merging two calls would make "which group is this rule in" — the
    // question the one-shot seed guard answers — unanswerable.
    registerEngagementSeeds(seeds) { once('registerEngagementSeeds'); record.engagementSeeds = seeds },
    // MODULE_API 1.10.0 (EVENTS.md F, EVENTS_PLAN.md Phases 7 and 9). `once` on
    // all three, matching core: it stages a registrant's whole batch and applies
    // it as one, so a second call is a module changing its mind mid-register().
    registerEventActions(actions) { once('registerEventActions'); record.eventActions = actions },
    registerEventBudgets(budgets) { once('registerEventBudgets'); record.eventBudgets = budgets },
    registerEventOptionSources(sources) { once('registerEventOptionSources'); record.eventOptionSources = sources },
    // And the fourth, from Phase 11b. `once` for the same reason, and present here
    // for a second one: a verb this module calls and this fake does not have is a
    // TypeError in `entry.test.js` rather than a surprise at somebody's boot.
    registerEventLeases(leases) { once('registerEventLeases'); record.eventLeases = leases },
    onBoot(fn) { once('onBoot'); record.hooks.onBoot = fn },
    onShutdown(fn) { once('onShutdown'); record.hooks.onShutdown = fn },
  }
  api.record = record
  return api
}

module.exports = { fakeCtx, fakeApi, spy }