// geoGreeting — a localized greeting based on the caller's country.
//
// Demonstrates: reading the raw request via `ctx.request.headers` (the geo
// header the edge host injects), plus an optional GET query param. The whole
// point of running at the edge is being close to the user — this reacts to
// where they are.
//
//   curl 'http://localhost:8910/?name=Ada' -H 'cf-ipcountry: DE'

import { Effect, Schema } from 'effect'
import { defineServerless } from '@voltro/serverless'

const HELLO: Record<string, string> = {
  DE: 'Hallo',
  FR: 'Bonjour',
  ES: 'Hola',
  IT: 'Ciao',
  JP: 'こんにちは',
  US: 'Hi',
  GB: 'Hello',
}

export default defineServerless({
  name: 'geo-greeting',
  method: 'GET',
  input: Schema.Struct({ name: Schema.optional(Schema.String) }),
  output: Schema.Struct({
    greeting: Schema.String,
    country: Schema.String,
  }),
  handler: ({ name }, ctx) =>
    Effect.sync(() => {
      // Cloudflare sets `cf-ipcountry`; other proxies use varied headers. We
      // read whatever the host injected — the function code stays the same.
      const country = (
        ctx.request.headers.get('cf-ipcountry') ??
        ctx.request.headers.get('x-vercel-ip-country') ??
        ctx.request.headers.get('x-forwarded-country') ??
        'XX'
      ).toUpperCase()
      const hello = HELLO[country] ?? 'Hello'
      return { greeting: `${hello}, ${name ?? 'there'}!`, country }
    }),
})