import { auth } from "@/auth";
import { db } from "@/lib/db";
import { hasPermission } from "@/lib/permissions";
import { notFound, redirect } from "next/navigation";
import { ApprovalActions } from "./approval-actions";
import { PoDetail } from "@/components/po/po-detail";
import { ManagerEditPoForm } from "./manager-edit-po-form";
import { buildAccountGroups } from "@/lib/cost-centre-groups";
import { formatDeliveryLocation } from "@/lib/delivery-location";
import { getTermsCatalogue } from "@/lib/terms-data";
import { parsePoTerms, legacyPoTerms } from "@/lib/terms";
import type { CompanyOption } from "@/app/(portal)/po/new/new-po-form";
import type { Metadata } from "next";

interface Props {
  params: Promise<{ id: string }>;
}

export const metadata: Metadata = { title: "Review PO" };

export default async function ApprovalDetailPage({ params }: Props) {
  const session = await auth();
  if (!session?.user) redirect("/login");

  if (!hasPermission(session.user.role, "approve_po")) redirect("/dashboard");

  const { id } = await params;

  const currentUser = await db.user.findUnique({
    where: { id: session.user.id },
    select: { signatureKey: true },
  });
  const hasSignature = !!(currentUser?.signatureKey);

  const [po, vessels, leafAccounts, vendors, companies, deliveryLocations] = await Promise.all([
    db.purchaseOrder.findUnique({
      where: { id },
      include: {
        submitter: true,
        vessel: true,
        site: { select: { id: true, name: true } },
        account: true,
        vendor: true,
        lineItems: { orderBy: { sortOrder: "asc" } },
        documents: { orderBy: { uploadedAt: "desc" } },
        actions: { include: { actor: true }, orderBy: { createdAt: "asc" } },
        receipt: true,
      },
    }),
    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
    db.account.findMany({
      where: { isActive: true, children: { none: {} } },
      orderBy: { code: "asc" },
      select: { id: true, code: true, name: true, parent: { select: { name: true, code: true, parent: { select: { name: true, code: true } } } } },
    }),
    db.vendor.findMany({ where: { isActive: true }, orderBy: { name: "asc" } }),
    db.company.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
    db.deliveryLocation.findMany({ where: { isActive: true }, orderBy: { createdAt: "asc" }, include: { company: { select: { name: true } } } }),
  ]);

  if (!po) notFound();
  if (po.status !== "MGR_REVIEW") redirect(`/po/${id}`);

  const accounts = buildAccountGroups(leafAccounts);
  const deliveryOptions = deliveryLocations.map((l) => formatDeliveryLocation(l.company.name, l.address));
  const termsCatalogue = await getTermsCatalogue();
  const savedTerms = parsePoTerms(po.terms);
  const initialTerms = savedTerms.length > 0 ? savedTerms : legacyPoTerms(po);

  const serializedPo = {
    ...po,
    totalAmount: po.totalAmount.toNumber(),
    lineItems: po.lineItems.map((li) => ({
      ...li,
      quantity: li.quantity.toNumber(),
      unitPrice: li.unitPrice.toNumber(),
      totalPrice: li.totalPrice.toNumber(),
      gstRate: li.gstRate.toNumber(),
    })),
  };

  return (
    <div className="max-w-6xl">
      <div className="mb-4 md:mb-6 flex items-center justify-between">
        <div>
          <h1 className="text-lg md:text-2xl font-semibold text-neutral-900">Review Purchase Order</h1>
          <p className="mt-0.5 text-sm text-neutral-500">{po.poNumber} — {po.title}</p>
        </div>
      </div>

      {!po.vendorId && (
        <div className="mb-4 rounded-lg border border-danger-100 bg-danger-50 px-4 py-3">
          <p className="text-sm font-medium text-danger-700">Vendor required before approval</p>
          <p className="text-sm text-danger-600 mt-0.5">
            This PO has no vendor assigned. Use &ldquo;Request Vendor ID&rdquo; to route it for vendor selection, or assign a vendor via the Edit PO form on desktop.
          </p>
        </div>
      )}

      <PoDetail po={po} currentUserId={session.user.id} currentRole={session.user.role} readOnly />

      <div className="hidden md:block">
        <ManagerEditPoForm
          po={serializedPo}
          vessels={vessels}
          accounts={accounts}
          vendors={vendors}
          companies={companies}
          deliveryOptions={deliveryOptions}
          termsCatalogue={termsCatalogue}
          initialTerms={initialTerms}
        />
      </div>

      <div className="mt-4 md:mt-6">
        {hasSignature ? (
          <ApprovalActions
            poId={po.id}
            poStatus={po.status}
            totalAmount={Number(po.totalAmount)}
            currency={po.currency}
          />
        ) : (
          <div className="rounded-lg border border-warning-200 bg-warning-50 p-4 md:p-5 flex items-start gap-3">
            <span className="text-warning-500 text-xl leading-none mt-0.5">✎</span>
            <div>
              <p className="text-sm font-semibold text-warning-800">Signature required to approve POs</p>
              <p className="text-sm text-warning-700 mt-0.5">
                You must upload your approval signature before you can approve, reject, or request edits on purchase orders.
              </p>
              <a href="/profile" className="mt-2 inline-block text-sm font-medium text-primary-600 hover:text-primary-700 underline">
                Go to Profile to upload your signature →
              </a>
            </div>
          </div>
        )}
      </div>
    </div>
  );
}
