import { NextResponse } from "next/server";
import { z } from "zod";
import { auth } from "@/auth";
import { isAdminRole } from "@/lib/admin";
import { prisma } from "@/lib/prisma";

const bodySchema = z.object({
  slug: z.string().min(1),
});

export async function POST(req: Request) {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  try {
    const json = await req.json();
    const { slug } = bodySchema.parse(json);

    const sku = await prisma.prizeSku.findUnique({ where: { slug } });
    if (!sku) {
      return NextResponse.json({ error: "Not found" }, { status: 404 });
    }

    const admin = isAdminRole(session.user!.role);

    const result = await prisma.$transaction(async (tx) => {
      if (!admin) {
        const wallet = await tx.wallet.findUnique({ where: { userId: session.user!.id } });
        if (!wallet || wallet.balanceCredits < sku.costCredits) {
          throw new Error("INSUFFICIENT_CREDITS");
        }
      }

      const redemption = await tx.redemption.create({
        data: {
          userId: session.user!.id,
          prizeSkuId: sku.id,
          creditsSpent: admin ? 0 : sku.costCredits,
        },
      });

      if (!admin) {
        await tx.ledgerEntry.create({
          data: {
            userId: session.user!.id,
            delta: -sku.costCredits,
            type: "DEBIT_SPEND",
            redemptionId: redemption.id,
            memo: `Redeem: ${sku.title}`,
          },
        });

        await tx.wallet.update({
          where: { userId: session.user!.id },
          data: { balanceCredits: { decrement: sku.costCredits } },
        });
      }

      return redemption.id;
    });

    return NextResponse.json({
      ok: true,
      redemptionId: result,
      adminBypass: admin,
    });
  } catch (e) {
    if (e instanceof z.ZodError) {
      return NextResponse.json({ error: "Invalid input", issues: e.issues }, { status: 400 });
    }
    if (e instanceof Error && e.message === "INSUFFICIENT_CREDITS") {
      return NextResponse.json({ error: "Insufficient BLW (Blue Wave)" }, { status: 402 });
    }
    console.error(e);
    return NextResponse.json({ error: "Redeem failed" }, { status: 500 });
  }
}