// Reports every page answered 404 to the SEO plugin's 404 log
// (POST /notfound with the bearer token). A page that throws a 404 (an
// unknown route, a missing record) goes through Nitro's error path, which
// skips afterResponse, so both the `error` hook and `afterResponse` report,
// once per request. Only page views count: GET requests that accept
// text/html, never Nuxt's own paths (/_nuxt, /__nuxt_error, …) or the API
// routes, and nothing without the token configured. A failed report is
// logged once and never touches the response.

import type { H3Event } from 'h3'
import { seoResolvableUrl } from '../../app/utils/seo.ts'

let warned = false

function report(event: H3Event) {
  if (event.context.seoNotFoundReported) return
  if (event.method !== 'GET') return
  if (!(getRequestHeader(event, 'accept') ?? '').includes('text/html')) return
  const config = useRuntimeConfig(event)
  if ((config.public.seo as { enabled?: boolean } | undefined)?.enabled === false) return
  const seo = config.seo as { apiBase: string; notfoundToken?: string; timeoutMs?: number }
  const token = seo.notfoundToken?.trim()
  if (!token) return
  const url = seoResolvableUrl(event.path)
  if (!url) return
  event.context.seoNotFoundReported = true

  const referer = getRequestHeader(event, 'referer') ?? ''
  const forwarded = event.context.seoForwardedFor as string | undefined
  const sent = $fetch('/notfound', {
    baseURL: seo.apiBase,
    method: 'POST',
    body: { url: url.slice(0, 2048), referer: referer.slice(0, 1024) },
    headers: { authorization: `Bearer ${token}`, ...(forwarded ? { 'x-forwarded-for': forwarded } : {}) },
    timeout: Number(seo.timeoutMs) || 1500,
  }).catch((err: unknown) => {
    if (!warned) {
      warned = true
      console.warn('[vue-seo-layer] 404 report failed:', (err as Error)?.message ?? err)
    }
  })
  event.waitUntil?.(sent)
}

export default defineNitroPlugin((nitroApp) => {
  nitroApp.hooks.hook('error', (error, { event }) => {
    const status = (error as { statusCode?: number } | null)?.statusCode
    if (event && status === 404) report(event)
  })
  nitroApp.hooks.hook('afterResponse', (event) => {
    if (event.node.res.statusCode === 404) report(event)
  })
})