"use client";

import { useState } from "react";
import { useRouter } from "next/navigation";
import { cancelBookingWithRefundAction } from "@/features/booking/actions";
import { formatRupiah } from "@/lib/utils";

interface CancelBookingButtonProps {
  tripId: string;
  /** Hasil preview server-side (dihitung di trip detail page). */
  preview: {
    days: number;
    refundAmount: number;
    bookingAmount: number;
    tierLabel: string;
  };
}

type ServerResult =
  | { kind: "REFUND_PENDING"; refundAmount: number; days: number }
  | { kind: "CANCELLED_NO_REFUND"; days: number };

export function CancelBookingButton({ tripId, preview }: CancelBookingButtonProps) {
  const router = useRouter();
  const [open, setOpen] = useState(false);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState("");
  const [result, setResult] = useState<ServerResult | null>(null);

  async function handleConfirm() {
    setLoading(true);
    setError("");
    const res = await cancelBookingWithRefundAction(tripId);
    setLoading(false);
    if ("error" in res) {
      setError(res.error ?? "Terjadi kesalahan");
      return;
    }
    setResult({
      kind: res.kind,
      refundAmount: res.refundAmount,
      days: res.days,
    } as ServerResult);
    router.refresh();
  }

  if (result?.kind === "REFUND_PENDING") {
    return (
      <div className="rounded-2xl border border-amber-200 bg-amber-50 p-4 text-sm text-amber-900">
        <p className="font-semibold">Request refund dibuat.</p>
        <p className="mt-1 text-xs">
          Refund <span className="font-bold">{formatRupiah(result.refundAmount)}</span>{" "}
          menunggu review admin. Setelah disetujui dan ditransfer manual, slot
          kamu di trip akan otomatis dibebaskan.
        </p>
      </div>
    );
  }

  if (result?.kind === "CANCELLED_NO_REFUND") {
    return (
      <div className="rounded-2xl border border-neutral-200 bg-neutral-50 p-4 text-sm text-neutral-700">
        <p className="font-semibold">Booking dibatalkan.</p>
        <p className="mt-1 text-xs">
          Pembatalan di H-{result.days} berada di luar window refund — tidak
          ada nominal yang dikembalikan.
        </p>
      </div>
    );
  }

  if (!open) {
    return (
      <button
        type="button"
        onClick={() => setOpen(true)}
        className="w-full rounded-xl border-2 border-red-200 py-3 text-sm font-bold text-red-600 transition-colors hover:bg-red-50"
      >
        Cancel & Request Refund
      </button>
    );
  }

  const percentage = preview.bookingAmount
    ? Math.floor((preview.refundAmount * 100) / preview.bookingAmount)
    : 0;
  const noRefund = preview.refundAmount === 0;

  return (
    <div className="space-y-3 rounded-2xl border-2 border-red-200 bg-red-50 p-4 text-sm">
      <div>
        <p className="font-bold text-red-900">Cancel booking?</p>
        <p className="mt-1 text-xs text-red-800/80">
          Kamu cancel di <span className="font-semibold">H-{preview.days}</span>{" "}
          dari tanggal berangkat.
        </p>
      </div>

      <div className="rounded-xl border border-red-200 bg-white p-3">
        <p className="text-xs font-semibold uppercase tracking-wide text-neutral-500">
          Estimasi refund (sesuai policy)
        </p>
        <p className="mt-1 text-lg font-bold text-neutral-900">
          {formatRupiah(preview.refundAmount)}
          {!noRefund && (
            <span className="ml-2 text-xs font-medium text-neutral-500">
              ({percentage}% dari {formatRupiah(preview.bookingAmount)})
            </span>
          )}
        </p>
        <p className="mt-1 text-[11px] text-neutral-500">
          Tier: {preview.tierLabel}
        </p>
        {noRefund ? (
          <p className="mt-2 text-xs text-red-700">
            ⚠️ Di luar window refund — uang tidak dikembalikan. Booking akan
            di-cancel langsung.
          </p>
        ) : (
          <p className="mt-2 text-xs text-neutral-600">
            Refund akan masuk antrian review admin. Setelah disetujui & uang
            ditransfer, booking otomatis ditandai{" "}
            {percentage === 100 ? "REFUNDED" : "PARTIALLY_REFUNDED"}.
          </p>
        )}
      </div>

      {error && (
        <div className="rounded-lg bg-white px-3 py-2 text-xs font-medium text-red-700">
          {error}
        </div>
      )}

      <div className="flex flex-wrap gap-2">
        <button
          type="button"
          onClick={handleConfirm}
          disabled={loading}
          className="rounded-xl bg-red-600 px-4 py-2 text-sm font-bold text-white hover:bg-red-700 disabled:opacity-50"
        >
          {loading
            ? "Memproses…"
            : noRefund
              ? "Konfirmasi Cancel"
              : "Konfirmasi & Request Refund"}
        </button>
        <button
          type="button"
          onClick={() => {
            setOpen(false);
            setError("");
          }}
          disabled={loading}
          className="rounded-xl border border-red-200 bg-white px-4 py-2 text-sm font-medium text-red-700 hover:bg-red-100 disabled:opacity-50"
        >
          Batal
        </button>
      </div>
    </div>
  );
}
