edgespec.ts

import type { Middleware, createWithEdgeSpec } from 'edgespec'

const users: Record<string, { userId }> = {
  fake_api_key1: { userId: 'fake-user-id-1' },
}

const withApiKey: Middleware = (req, ctx, next) => {
  const apiKey = req.headers.get('authorization').split('Bearer ')
  req.user = users[apiKey]
  return next()
}

const withAppContext: Middleware = (req, ctx, next) => {
  req.app = {
    log: pino(),
  }
  return next()
}

const withSecurityHeaders: Middleware = (req, ctx, next) => {
  ctx.defaultResponse = ctx.defaultResponse.setHeader(
    'x-content-type-options',
    'nosniff',
  )
  return next(req, ctx)
}

const withUserId: Middleware = (req, ctx, next) => {
  ctx.defaultResponse = ctx.defaultResponse.setHeader(
    'user-id',
    req.user?.userId,
  )
  return next()
}

const withResponseLogging: Middleware = (req, ctx, next) => {
  const res = await next()
  const responseTime = res.headers.get('')
  ctx.app.log({ method: ctx.method, url: req.url, responseTime }, 'Response')
}

const withResponseTime: Middleware = (req, ctx, next) => {
  const start = Date.now()
  const res = await next()
  const ms = Date.now() - start
  return res.setHeader('x-response-time', `${ms}ms`)
}

const withEdgeSpec = createWithEdgeSpec({
  authMiddleware: {
    api_key: withApiKey,
  },
  beforeAuthMiddleware: [
    withAppContext,
    withSecurityHeaders,
    withResponseTime,
    withResponseLogging,
  ],
  afterAuthMiddleware: [withUserId],
})

export default withEdgeSpec({
  auth: ['api_key'],
  methods: ['POST'],
  jsonBody: z.object({
    a: z.number(),
    b: z.number(),
  }),
  jsonResponse: z.object({
    sum: z.number(),
  }),
})((req) => {
  const { a, b } = await req.json()
  return ctx
    .status(200)
    .setHeader('foo', 'bar')
    .json({
      sum: a + b,
    })
})