import { NextRequest, NextResponse } from "next/server";
import { z } from "zod";
import { and, eq } from "@epicure/db";
import { db, recipes } from "@epicure/db";
import { requireSession } from "@/lib/api-auth";
import { checkTierLimit, incrementUsage } from "@/lib/tiers";
import { suggestVariations } from "@/lib/ai/features/suggest-variations";
import { withUserKey } from "@/lib/ai/resolve-user-key";

const Schema = z.object({
  count: z.number().int().min(1).max(5).default(3),
  directions: z.string().max(500).optional(),
  provider: z.enum(["openai", "anthropic", "openrouter", "ollama"]).optional(),
  model: z.string().optional(),
});

type Params = { params: Promise<{ id: string }> };

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

  const { id } = await params;
  const recipe = await db.query.recipes.findFirst({
    where: and(eq(recipes.id, id), eq(recipes.authorId, session!.user.id)),
    with: {
      ingredients: { orderBy: (t, { asc }) => asc(t.order) },
      steps: { orderBy: (t, { asc }) => asc(t.order) },
    },
  });

  if (!recipe) return NextResponse.json({ error: "Not found" }, { status: 404 });

  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 });
  }

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

  const aiConfig = await withUserKey(session!.user.id, { provider: parsed.data.provider, model: parsed.data.model });
  const variations = await suggestVariations(
    {
      title: recipe.title,
      description: recipe.description,
      ingredients: recipe.ingredients,
      steps: recipe.steps,
    },
    parsed.data.count,
    aiConfig,
    parsed.data.directions,
    (session!.user as { locale?: string }).locale ?? "en"
  );

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

  return NextResponse.json({ variations });
}