import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { requireSession } from "@/lib/api-auth";
import { applyRateLimit } from "@/lib/rate-limit";
import { checkTierLimit, incrementUsage } from "@/lib/tiers";
import { generateRecipe } from "@/lib/ai/features/generate-recipe";

const Schema = z.object({
  prompt: z.string().min(3).max(500),
  language: z.string().max(10).default("en"),
  provider: z.enum(["openai", "anthropic", "openrouter", "ollama"]).optional(),
  model: z.string().optional(),
});

export async function POST(req: NextRequest) {
  const { session, response } = await requireSession();
  if (response) return response;

  const body = await req.json() as unknown;
  const parsed = Schema.safeParse(body);
  if (!parsed.success) {
    return NextResponse.json({ error: "Validation error", issues: parsed.error.issues }, { status: 400 });
  }

  const limited = await applyRateLimit(`rl:ai:${session!.user.id}`, 10, 60);
  if (limited) return limited;

  await checkTierLimit(session!.user.id, session!.user.tier as "free" | "pro", "aiCall");

  const recipe = await generateRecipe(parsed.data.prompt, {
    provider: parsed.data.provider,
    model: parsed.data.model,
    language: parsed.data.language,
  });

  await incrementUsage(session!.user.id, "aiCall");

  return NextResponse.json(recipe);
}