import { NextResponse } from "next/server";
import { z } from "zod";
import { auth } from "@/auth";
import { isAdminRole } from "@/lib/admin";
import { creditDisplayName } from "@/lib/credits-brand";
import { prisma } from "@/lib/prisma";
import { debitWalletCredits, INSUFFICIENT_CREDITS } from "@/lib/wallet-safety";

const ISSUE_CATALOG = [
  { slug: "voting-rights", title: "Voting Rights & Access" },
  { slug: "healthcare", title: "Affordable Healthcare" },
  { slug: "climate", title: "Climate & Clean Energy Jobs" },
  { slug: "education", title: "Public Education Funding" },
  { slug: "gun-safety", title: "Common-Sense Gun Safety" },
  { slug: "workers-rights", title: "Workers Rights & Wages" },
  { slug: "housing", title: "Affordable Housing" },
  { slug: "democracy-reform", title: "Campaign Finance Reform" },
] as const;

function currentWeekOf(): string {
  const d = new Date();
  const day = d.getUTCDay();
  const diff = d.getUTCDate() - day + (day === 0 ? -6 : 1);
  const mon = new Date(Date.UTC(d.getUTCFullYear(), d.getUTCMonth(), diff));
  return mon.toISOString().split("T")[0];
}

const postSchema = z.object({
  issueSlug: z.string().min(2).max(80),
  creditsSpent: z.number().int().min(5).max(10000),
});

export async function GET() {
  const weekOf = currentWeekOf();
  const bids = await prisma.spotlightBid.groupBy({
    by: ["issueSlug", "issueTitle"],
    where: { weekOf },
    _sum: { creditsSpent: true },
    _count: true,
    orderBy: { _sum: { creditsSpent: "desc" } },
  });

  const totals = bids.map((b) => ({
    issueSlug: b.issueSlug,
    issueTitle: b.issueTitle,
    total: b._sum.creditsSpent ?? 0,
    backers: b._count,
  }));

  const leader = totals[0] ?? null;

  return NextResponse.json({ weekOf, totals, leader, catalog: ISSUE_CATALOG });
}

export async function POST(req: Request) {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json({ error: "Sign in to bid on a Spotlight." }, { status: 401 });
  }

  const admin = isAdminRole(session.user.role);
  const creditName = creditDisplayName();

  try {
    const json = await req.json();
    const { issueSlug, creditsSpent } = postSchema.parse(json);

    const issue = ISSUE_CATALOG.find((i) => i.slug === issueSlug);
    if (!issue) return NextResponse.json({ error: "Unknown issue." }, { status: 400 });

    const weekOf = currentWeekOf();
    const spent = admin ? 0 : creditsSpent;

    await prisma.$transaction(async (tx) => {
      const bid = await tx.spotlightBid.create({
        data: {
          userId: session.user.id,
          issueSlug: issue.slug,
          issueTitle: issue.title,
          creditsSpent: spent,
          weekOf,
        },
      });

      if (!admin) {
        await debitWalletCredits(tx, session.user.id, creditsSpent);

        await tx.ledgerEntry.create({
          data: {
            userId: session.user.id,
            delta: -creditsSpent,
            type: "DEBIT_SPOTLIGHT",
            spotlightBidId: bid.id,
            memo: `Spotlight bid: ${issue.title}`,
          },
        });
      }
    });

    return NextResponse.json({ ok: true, issue, weekOf, spent });
  } 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: `Not enough ${creditName}.` }, { status: 402 });
    }
    console.error(e);
    return NextResponse.json({ error: "Could not place bid." }, { status: 500 });
  }
}