since3-portal/app/api/ai/generate/route.ts

import { betaZodOutputFormat } from "@anthropic-ai/sdk/helpers/beta/zod"
import type * as z from "zod"
import { contentSystem, emailSystem, quoteSystem } from "@/modules/templates/ai/prompts"
import { ContentSchema, GenerateRequestSchema, QuoteSchema, type AiEvent } from "@/modules/templates/ai/schemas"
import { AI_MODEL, FALLBACK, aiErrorMessage, getAnthropic, ndjsonResponse, resolveAiAccess } from "@/modules/templates/ai/server"

export const maxDuration = 90

async function structured<T extends z.ZodType>(schema: T, system: string, prompt: string) {
    const response = await getAnthropic().beta.messages.parse({
        ...FALLBACK,
        model: AI_MODEL,
        max_tokens: 16000,
        output_config: { effort: "medium", format: betaZodOutputFormat(schema) },
        system,
        messages: [{ role: "user", content: prompt }],
    })
    return response.stop_reason === "refusal" ? null : response.parsed_output
}

// Angebots- und E-Mail-Assistent sowie Content-Generator
export async function POST(request: Request) {
    const parsed = GenerateRequestSchema.safeParse(await request.json().catch(() => null))
    if (!parsed.success) return Response.json({ error: "Bitte die Eingabe prüfen (mindestens ein paar Worte)." }, { status: 400 })

    const input = parsed.data
    const ctx = await resolveAiAccess(input.access, input.task === "content" ? "content" : "assistant")
    if ("error" in ctx) return Response.json({ error: ctx.error }, { status: ctx.status })

    if (input.task === "email") {
        const encoder = new TextEncoder()
        const body = new ReadableStream<Uint8Array>({
            async start(controller) {
                const send = (event: AiEvent) => controller.enqueue(encoder.encode(`${JSON.stringify(event)}\n`))
                try {
                    const stream = getAnthropic().beta.messages.stream({
                        ...FALLBACK,
                        model: AI_MODEL,
                        max_tokens: 8000,
                        output_config: { effort: "medium" },
                        system: emailSystem(ctx),
                        messages: [{ role: "user", content: `<anfrage>\n${input.inquiry}\n</anfrage>` }],
                    })
                    stream.on("text", (text) => send({ type: "text", text }))
                    const message = await stream.finalMessage()
                    send(message.stop_reason === "refusal" ? { type: "error", message: "Dazu kann ich keine Antwort schreiben." } : { type: "done" })
                } catch (error) {
                    console.error("AI email failed", error)
                    send({ type: "error", message: aiErrorMessage(error) })
                }
                controller.close()
            },
        })
        return ndjsonResponse(body)
    }

    try {
        const result =
            input.task === "quote"
                ? await structured(QuoteSchema, quoteSystem(ctx), `<anfrage>\n${input.inquiry}\n</anfrage>`)
                : await structured(ContentSchema, contentSystem(ctx, input.channel, input.tone), `Thema: ${input.topic}`)
        if (!result) return Response.json({ error: "Dazu konnte die KI nichts erstellen. Bitte die Eingabe umformulieren." }, { status: 422 })
        return Response.json({ result })
    } catch (error) {
        console.error("AI generate failed", error)
        return Response.json({ error: aiErrorMessage(error) }, { status: 502 })
    }
}