/**
 * Client-triggered claim: user polls their invoice status and calls this
 * when it shows "Settled". Server re-verifies with BTCPay before crediting.
 *
 * POST /api/credits/claim  { invoiceId, handle }
 */

import { NextResponse } from "next/server";
import { getBtcPayInvoiceStatus } from "@/lib/btcpay";
import {
  creditInvoice,
  getInvoiceHandle,
  isInvoiceClaimed,
  satsToVoid,
} from "@/lib/serverLedger";

export async function POST(req: Request) {
  let body: unknown;
  try { body = await req.json(); } catch {
    return NextResponse.json({ ok: false, error: "Invalid JSON" }, { status: 400 });
  }

  const { invoiceId, handle } = (body as Record<string, unknown>) ?? {};

  if (typeof invoiceId !== "string" || !invoiceId.trim()) {
    return NextResponse.json({ ok: false, error: "invoiceId is required" }, { status: 400 });
  }
  if (typeof handle !== "string" || !handle.trim()) {
    return NextResponse.json({ ok: false, error: "handle is required" }, { status: 400 });
  }

  const cleanInvoice = invoiceId.trim();
  const cleanHandle = handle.trim();

  if (isInvoiceClaimed(cleanInvoice)) {
    const { getVoidBalance } = await import("@/lib/serverLedger");
    return NextResponse.json({
      ok: true,
      alreadyClaimed: true,
      voidBalance: getVoidBalance(cleanHandle),
    });
  }

  // Verify invoice handle matches (only the rightful account can claim)
  const registeredHandle = getInvoiceHandle(cleanInvoice);
  if (registeredHandle && registeredHandle !== cleanHandle.toLowerCase()) {
    return NextResponse.json({ ok: false, error: "Invoice does not belong to this handle" }, { status: 403 });
  }

  // Re-verify settled status with BTCPay
  const status = await getBtcPayInvoiceStatus(cleanInvoice);
  if (!status.ok) {
    return NextResponse.json({ ok: false, error: status.error }, { status: 502 });
  }
  if (status.status !== "Settled") {
    return NextResponse.json({
      ok: false,
      error: `Invoice not settled yet (status: ${status.status})`,
      status: status.status,
    });
  }

  // Convert USD → VOID credits
  let voidToCredit = 0;
  try {
    const priceRes = await fetch(
      "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd",
      { next: { revalidate: 60 } },
    );
    const priceJson = (await priceRes.json()) as { bitcoin?: { usd?: number } };
    const btcUsd = priceJson.bitcoin?.usd ?? 0;
    if (btcUsd > 0) {
      const sats = Math.floor((status.usdAmount / btcUsd) * 1e8);
      voidToCredit = satsToVoid(sats);
    }
  } catch { /* ignore */ }

  if (voidToCredit <= 0) voidToCredit = Math.max(1, Math.floor(status.usdAmount));

  const credited = creditInvoice(cleanInvoice, cleanHandle, voidToCredit);

  const { getVoidBalance } = await import("@/lib/serverLedger");
  return NextResponse.json({
    ok: true,
    credited,
    voidCredited: voidToCredit,
    voidBalance: getVoidBalance(cleanHandle),
    usdAmount: status.usdAmount,
  });
}