// The frozen manifest's derivation, checked.
//
// `scripts/frozenManifest.js` runs in one place — a CI job with a whole core
// checked out beside it — so it is the least-exercised piece of machinery in this
// repo, and it is the piece that decides whether the URLs this module claims are
// the URLs it serves (MODULE_API.md §5.3). Its three answers are pure functions of
// two manifests and a fragment, so all three are asked here, with fixtures rather
// than a clone.
//
// What is deliberately NOT asserted here: the numbers. `routes.manifest.json`'s
// routes are proved by the job that generates them from a real core, and a copy of
// that count in this file would only ever be a second thing to update.

const test = require('node:test')
const assert = require('node:assert')
const fs = require('node:fs')
const path = require('node:path')

const { diffManifests, coverage, MANIFEST, FRAGMENT } = require('../scripts/frozenManifest')

const manifest = (public_ = [], internal = []) => ({ public: public_, internal })
const get = (p) => ({ method: 'GET', path: p })

test("the module's routes are the ones a core gains by loading it", () => {
  const before = manifest([get('/api/v1/public/settings')])
  const after = manifest([get('/api/v1/public/settings'), get('/api/v1/public/rust/servers')])

  const { added, removed } = diffManifests(before, after)
  assert.deepStrictEqual(removed, [])
  assert.deepStrictEqual(added, [{ method: 'GET', path: '/api/v1/public/rust/servers', tier: 'public' }])
})

test('a route core loses to the module is reported, not quietly absorbed', () => {
  // The failure this exists for, and the one phase 1 could only check by reading:
  // core mounts several routes at the TIER ROOT (/status, /version) that the
  // loader's collision probe cannot see, so a module whose mount displaced one
  // would not show up as an addition — the URL is unchanged — and a check that
  // only looked at what appeared would call it clean.
  const before = manifest([get('/api/v1/public/settings'), get('/api/v1/public/status')])
  const after = manifest([get('/api/v1/public/settings')])

  const { removed } = diffManifests(before, after)
  assert.deepStrictEqual(removed, ['public GET /api/v1/public/status'])
})

test('a route whose METHOD changed counts as removed and added', () => {
  const { added, removed } = diffManifests(
    manifest([{ method: 'POST', path: '/api/v1/admin/thing' }]),
    manifest([{ method: 'PUT', path: '/api/v1/admin/thing' }]),
  )
  assert.deepStrictEqual(removed, ['public POST /api/v1/admin/thing'])
  assert.strictEqual(added.length, 1)
})

test('the internal app is diffed too, and keeps its own tier', () => {
  const { added } = diffManifests(
    manifest([], [get('/internal/health')]),
    manifest([], [get('/internal/health'), get('/internal/rust/thing')]),
  )
  assert.deepStrictEqual(added, [{ method: 'GET', path: '/internal/rust/thing', tier: 'internal' }])
})

test('added routes are sorted, so the committed file does not churn on traversal order', () => {
  const { added } = diffManifests(
    manifest([]),
    manifest([get('/b'), get('/a'), { method: 'POST', path: '/a' }]),
  )
  assert.deepStrictEqual(
    added.map((r) => `${r.method} ${r.path}`),
    ['GET /a', 'GET /b', 'POST /a'],
  )
})

// ── coverage: the route ⇄ fragment agreement ────────────────────────────────

const fragment = (paths) => ({ paths })

test('a served route with no documented operation is named', () => {
  const { undocumented, unserved } = coverage([get('/api/v1/public/rust/servers')], fragment({}))
  assert.deepStrictEqual(undocumented, ['GET /api/v1/public/rust/servers'])
  assert.deepStrictEqual(unserved, [])
})

test('a documented operation nobody serves is named too', () => {
  // The direction core's own spec has no check for, which is how it accumulated
  // orphan tags and schemas describing routes that had moved out of it. A
  // documented URL nobody serves is a client following the docs into a 404.
  const { undocumented, unserved } = coverage([], fragment({ '/api/v1/public/rust/gone': { get: {} } }))
  assert.deepStrictEqual(undocumented, [])
  assert.deepStrictEqual(unserved, ['GET /api/v1/public/rust/gone'])
})

test('express :params and OpenAPI {params} are the same route', () => {
  const { undocumented, unserved } = coverage(
    [{ method: 'DELETE', path: '/api/v1/admin/rust/servers/:id' }],
    fragment({ '/api/v1/admin/rust/servers/{id}': { delete: {} } }),
  )
  assert.deepStrictEqual(undocumented, [])
  assert.deepStrictEqual(unserved, [])
})

test('methods are matched, not just paths', () => {
  const { undocumented, unserved } = coverage(
    [{ method: 'POST', path: '/api/v1/admin/rust/servers/:id/test' }],
    fragment({ '/api/v1/admin/rust/servers/{id}/test': { get: {} } }),
  )
  assert.deepStrictEqual(undocumented, ['POST /api/v1/admin/rust/servers/{id}/test'])
  assert.deepStrictEqual(unserved, ['GET /api/v1/admin/rust/servers/{id}/test'])
})

// ── the committed artifacts, against each other ─────────────────────────────
//
// These two files are generated together by a job that has a real core; here
// there is no core, so what can still be asked is whether they agree with each
// other. If they do not, one of them was committed without the other.

test('every route in the committed manifest has a committed operation', () => {
  const { routes } = JSON.parse(fs.readFileSync(MANIFEST, 'utf8'))
  const spec = JSON.parse(fs.readFileSync(FRAGMENT, 'utf8'))
  const { undocumented, unserved } = coverage(routes, spec)
  assert.deepStrictEqual(undocumented, [], 'routes.manifest.json lists routes swagger-fragment.json does not document')
  assert.deepStrictEqual(unserved, [], 'swagger-fragment.json documents operations routes.manifest.json does not list')
})

test('the fragment carries only the three sections §6.1a allows', () => {
  const spec = JSON.parse(fs.readFileSync(FRAGMENT, 'utf8'))
  assert.deepStrictEqual(Object.keys(spec).sort(), ['components', 'paths', 'tags'])
  assert.deepStrictEqual(Object.keys(spec.components), ['schemas'])
})

test("the fragment defines only namespaced schemas, and redefines none of core's", () => {
  const spec = JSON.parse(fs.readFileSync(FRAGMENT, 'utf8'))
  for (const name of Object.keys(spec.components.schemas)) {
    assert.match(name, /^Rust[A-Z]/, `${name} is not namespaced — core wins the collision and drops it (§6.1a)`)
  }
  // Anything this fragment REFERENCES and does not define has to be one of
  // core's shared schemas, which resolve in the merged document — that is the
  // whole point of a fragment. A typo'd $ref is otherwise invisible until a
  // reader opens /api/docs.json and finds a dangling pointer.
  const refs = JSON.stringify(spec.paths).match(/#[/]components[/]schemas[/]([A-Za-z0-9_]+)/g) || []
  const shared = ['Error', 'ValidationError']
  for (const name of new Set(refs.map((r) => r.split('/').pop()))) {
    const resolvable = Object.hasOwn(spec.components.schemas, name) || shared.includes(name)
    assert.ok(resolvable, `$ref to ${name} resolves to nothing — not defined here, not one of core's shared schemas`)
  }
})

test('every path in the fragment is fully qualified', () => {
  const spec = JSON.parse(fs.readFileSync(FRAGMENT, 'utf8'))
  for (const p of Object.keys(spec.paths)) {
    // §6.1a: core merges the fragment verbatim and never re-derives a prefix, so
    // a router-relative path here is a path nothing serves.
    assert.match(p, /^\/api\/v1\/(public|admin|player)\//, `${p} is not a fully-qualified URL`)
    assert.doesNotMatch(p, /\/$/, `${p} has a trailing slash — no client calls that URL`)
  }
})

test("the manifest and the module's declared mounts agree", () => {
  const { routes } = JSON.parse(fs.readFileSync(MANIFEST, 'utf8'))
  const { mounts } = JSON.parse(fs.readFileSync(path.join(__dirname, '..', '..', 'module.json'), 'utf8'))

  const declared = []
  for (const [tier, prefixes] of Object.entries(mounts)) {
    for (const prefix of prefixes) declared.push(`/api/v1/${tier}${prefix}/`)
  }

  // Every route this module serves is under a prefix it declared. There is no
  // exception here yet, and that is the point of asserting it now: phase 6 adds
  // the `admin.users.detail` extension slot, whose routes live under core's
  // `/api/v1/admin/users/` rather than under any mount of ours (§2.4). When that
  // arrives this test must grow the exception deliberately, rather than a route
  // outside every declared mount arriving unnoticed.
  for (const route of routes) {
    const under = declared.some((d) => route.path.startsWith(d))
    assert.ok(under, `${route.method} ${route.path} is served from outside every mount module.json declares`)
  }
})