import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/auth'
import { getTagsProvider } from '@/lib/ai/factory'
import { getSystemConfig } from '@/lib/config'
import { hasUserAiConsent } from '@/lib/consent/server-consent'
import { reserveUsageOrThrow, QuotaExceededError } from '@/lib/entitlements'

export async function POST(request: NextRequest) {
  try {
    const session = await auth()
    if (!session?.user?.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
    }

    if (!(await hasUserAiConsent())) {
      return NextResponse.json({ error: 'ai_consent_required' }, { status: 403 })
    }

    const { text, targetLanguage } = await request.json()

    if (!text || !targetLanguage) {
      return NextResponse.json({ error: 'text and targetLanguage are required' }, { status: 400 })
    }

    const config = await getSystemConfig()
    const provider = getTagsProvider(config)

    await reserveUsageOrThrow(session.user.id, 'reformulate')

    const prompt = `Translate the following text to ${targetLanguage}. Return ONLY the translated text, no explanation, no preamble, no quotes:\n\n${text}`

    const translatedText = await provider.generateText(prompt)

    return NextResponse.json({ translatedText: translatedText.trim() })
  } catch (error: unknown) {
    if (error instanceof QuotaExceededError) {
      return NextResponse.json(error.toJSON(), { status: 429 })
    }
    const message = error instanceof Error ? error.message : 'Translation failed'
    return NextResponse.json({ error: message }, { status: 500 })
  }
}