import { NextRequest, NextResponse } from "next/server";
import { prisma } from "@/lib/prisma";

export const dynamic = "force-dynamic";
export const revalidate = 0;

export async function GET(req: NextRequest) {
  const url = new URL(req.url);
  const limit = Math.min(parseInt(url.searchParams.get("limit") ?? "25"), 100);

  // Aggregate total donated per user
  const rows = await prisma.donation.groupBy({
    by: ["userId"],
    where: { userId: { not: null }, status: "succeeded" },
    _sum: { amountUsdCents: true },
    _count: { id: true },
    orderBy: { _sum: { amountUsdCents: "desc" } },
    take: limit,
  });

  // Fetch display names
  const userIds = rows.map((r) => r.userId).filter((id): id is string => id != null);
  const users = await prisma.user.findMany({
    where: { id: { in: userIds } },
    select: { id: true, name: true, email: true },
  });

  const userMap = new Map(users.map(u => [u.id, u]));

  const leaderboard = rows.map((row, idx) => {
    const uid = row.userId!;
    const user = userMap.get(uid);
    // Show name if present, else obfuscate email
    let displayName = user?.name ?? "Anonymous";
    // Ghost donors have emails ending in leaderboard.local — show name only
    // Real donors: show first name + last initial, or truncated email
    const email = user?.email ?? "";
    if (!user?.name && !email.endsWith("leaderboard.local")) {
      const [local] = email.split("@");
      displayName = local.slice(0, 3) + "***";
    }
    return {
      rank: idx + 1,
      displayName,
      totalUsdCents: row._sum.amountUsdCents ?? 0,
      donationCount: row._count.id,
    };
  });

  return NextResponse.json({ leaderboard });
}