// Copied from https://github.com/atinux/nuxt-auth-utils/issues/91#issuecomment-2476019136

import { appendResponseHeader } from 'h3'
import { parse, parseSetCookie, serialize } from 'cookie-es'
import { jwtDecode, type JwtPayload } from 'jwt-decode'

export default defineNuxtRouteMiddleware(async (to, from) => {
  const nuxtApp = useNuxtApp()
  // Don't run on client hydration when server rendered
  if (import.meta.client && nuxtApp.isHydrating && nuxtApp.payload.serverRendered) return

  console.log('🔍 Middleware: refreshToken.global.ts')
  console.log(`  from: ${from.fullPath} to: ${to.fullPath}`)

  const { session, clear: clearSession, fetch: fetchSession } = useUserSession()
  // Ignore if no tokens
  if (!session.value?.jwt) return

  const serverEvent = useRequestEvent()
  const runtimeConfig = useRuntimeConfig()
  const { accessToken, refreshToken } = session.value.jwt

  const accessPayload = jwtDecode(accessToken)
  const refreshPayload = jwtDecode(refreshToken)

  // Both tokens expired, clearing session
  if (isExpired(accessPayload) && isExpired(refreshPayload)) {
    console.info('both tokens expired, clearing session')
    await clearSession()
    return navigateTo('/login')
  } else if (isExpired(accessPayload)) {
    console.info('access token expired, refreshing')
    await useRequestFetch()('/api/jwt/refresh', {
      method: 'POST',
      onResponse({ response: { headers } }) {
        // Forward the Set-Cookie header to the main server event
        if (import.meta.server && serverEvent) {
          for (const setCookie of headers.getSetCookie()) {
            appendResponseHeader(serverEvent, 'Set-Cookie', setCookie)
            // Update session cookie for next fetch requests
            const { name, value } = parseSetCookie(setCookie)

            if (name === runtimeConfig.session.name) {
              console.log('updating headers.cookie to', value)
              const cookies = parse(serverEvent.headers.get('cookie') || '')

              // set or overwrite existing cookie
              cookies[name] = value

              // update cookie event header for future requests
              serverEvent.headers.set(
                'cookie',
                Object.entries(cookies)
                  .map(([name, value]) => serialize(name, value))
                  .join('; ')
              )

              // Also apply to serverEvent.node.req.headers
              if (serverEvent.node?.req?.headers) {
                serverEvent.node.req.headers['cookie'] = serverEvent.headers.get('cookie') || ''
              }
            }
          }
        }
      },
      onError() {
        console.error('🔍 Middleware: Token refresh failed')
        const { loggedIn } = useUserSession()
        if (!loggedIn.value) {
          console.log('🔍 Middleware: User not logged in, redirecting to /login')
          return navigateTo('/login')
        }
      }
    })

    // Refresh the session
    await fetchSession()
  }
})

function isExpired(payload: JwtPayload) {
  return payload?.exp && payload.exp < Date.now() / 1000
}