import { useQuery } from "@tanstack/react-query";
import { Link } from "react-router-dom";
import {
  Receipt,
  FileSearch,
  ClipboardList,
  CreditCard,
  FileClock,
  ChevronRight,
} from "lucide-react";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { dashboardService, invoiceService } from "@/services";
import { Badge } from "@/components/ui/badge";
import { format } from "date-fns";
import { cn } from "@/lib/utils";

const COLORS = ["#10b981", "#f59e0b", "#ef4444", "#3b82f6", "#8b5cf6"];

const COMMERCE_QUICK_LINKS = [
  {
    label: "Invoices",
    description: "Browse, search, and manage issued invoices.",
    path: "/admin/invoices",
    icon: Receipt,
    color: "text-slate-700",
  },
  {
    label: "Proforma",
    description: "View and manage proforma invoices and drafts.",
    path: "/admin/proforma",
    icon: FileSearch,
    color: "text-blue-600",
  },
  {
    label: "Proforma requests",
    description: "Review and process incoming proforma requests.",
    path: "/admin/proforma-requests",
    icon: ClipboardList,
    color: "text-violet-600",
  },
  {
    label: "Payments",
    description: "Recorded payments and transaction history.",
    path: "/admin/payments",
    icon: CreditCard,
    color: "text-emerald-600",
  },
  {
    label: "Payment requests",
    description: "Pending and processed payment requests.",
    path: "/admin/payment-requests",
    icon: FileClock,
    color: "text-amber-600",
  },
] as const;

export default function DashboardPage() {
  const { data: metrics, isLoading: metricsLoading } = useQuery({
    queryKey: ["admin", "dashboard", "metrics"],
    queryFn: () => dashboardService.getMetrics(),
  });

  const { data: scannedInvoices, isLoading: scannedLoading } = useQuery({
    queryKey: ["admin", "dashboard", "scanned"],
    queryFn: () => dashboardService.getScannedInvoices(),
  });

  const { data: statusBreakdown, isLoading: statusLoading } = useQuery({
    queryKey: ["admin", "dashboard", "status-breakdown"],
    queryFn: () => dashboardService.getInvoiceStatusBreakdown(),
  });

  const { data: proformaRequests, isLoading: requestsLoading } = useQuery({
    queryKey: ["admin", "dashboard", "proforma-requests"],
    queryFn: () => invoiceService.getProformaRequests({ limit: 5 }),
  });

  const formatCurrency = (amount: number) => {
    return new Intl.NumberFormat("en-US", {
      style: "currency",
      currency: "USD",
      maximumFractionDigits: 0,
    }).format(amount);
  };

  const dataLoading =
    metricsLoading || scannedLoading || statusLoading || requestsLoading;

  return (
    <div className="p-8 space-y-12 max-w-7xl mx-auto bg-white min-h-screen">
      <header>
        <h1 className="text-3xl font-bold text-gray-900 tracking-tight">
          Dashboard Overview
        </h1>
        <p className="text-gray-500 mt-1">
          Operational status and pending verification items.
        </p>
      </header>

      {/* Quick access — invoices, proforma, payments */}
      <section className="space-y-4">
        <h2 className="text-sm font-bold text-gray-400 uppercase tracking-widest">
          Quick access
        </h2>
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-5 gap-4">
          {COMMERCE_QUICK_LINKS.map((item) => (
            <Link
              key={item.path}
              to={item.path}
              className="group block rounded-none outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2"
            >
              <Card className="h-full cursor-pointer border-slate-200/60 shadow-sm hover:shadow-md transition-all rounded-none bg-white overflow-hidden">
                <CardHeader className="pb-2 space-y-0 border-b border-slate-50 bg-slate-50/30">
                  <div className="flex items-center justify-between">
                    <span className="text-[10px] font-bold uppercase tracking-widest text-slate-400">
                      {item.label}
                    </span>
                    <item.icon
                      className={cn(
                        "w-4 h-4 shrink-0 transition-colors",
                        item.color,
                      )}
                    />
                  </div>
                </CardHeader>
                <CardContent className="pt-3 pb-4 flex items-end justify-between gap-2">
                  <p className="text-xs text-muted-foreground leading-relaxed line-clamp-3">
                    {item.description}
                  </p>
                  <ChevronRight className="w-4 h-4 shrink-0 text-slate-300 group-hover:translate-x-0.5 transition-transform" />
                </CardContent>
              </Card>
            </Link>
          ))}
        </div>
      </section>

      {dataLoading ? (
        <div className="py-16 text-center text-gray-500 font-medium border border-dashed border-gray-200 rounded-none">
          Loading dashboard data…
        </div>
      ) : (
        <>
      {/* Top Metrics Cards */}
      <section className="grid grid-cols-1 md:grid-cols-3 gap-6">
        <Card className="border-none bg-gray-50 shadow-none rounded-none">
          <CardHeader className="pb-1">
            <CardTitle className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
              Gross Revenue
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-3xl font-black text-gray-900">
              {formatCurrency(metrics?.totalRevenue || 0)}
            </div>
          </CardContent>
        </Card>

        <Card className="border-none bg-gray-50 shadow-none rounded-none">
          <CardHeader className="pb-1">
            <CardTitle className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
              Total Payments
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-3xl font-black text-gray-900">
              {(metrics?.totalPayments || 0).toLocaleString()}
            </div>
          </CardContent>
        </Card>

        <Card className="border-none bg-gray-50 shadow-none rounded-none">
          <CardHeader className="pb-1">
            <CardTitle className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
              Total Invoices
            </CardTitle>
          </CardHeader>
          <CardContent>
            <div className="text-3xl font-black text-gray-900">
              {(metrics?.totalInvoices || 0).toLocaleString()}
            </div>
          </CardContent>
        </Card>
      </section>

      {/* Invoice Status Breakdown (Full Width) */}
      <section className="space-y-4">
        <h2 className="text-xl font-bold text-gray-900">
          Invoice Status Breakdown
        </h2>
        <div className="border bg-white divide-y overflow-hidden rounded-none">
          {statusBreakdown && statusBreakdown.length > 0 ? (
            statusBreakdown.map((item, idx) => (
              <div
                key={idx}
                className="p-4 flex items-center justify-between hover:bg-gray-50"
              >
                <div className="flex items-center gap-3">
                  <div
                    className="w-2.5 h-2.5"
                    style={{ backgroundColor: COLORS[idx % COLORS.length] }}
                  />
                  <span className="text-sm font-bold uppercase tracking-wide text-gray-700">
                    {item.status}
                  </span>
                </div>
                <span className="text-lg font-black text-gray-900">
                  {item.count.toLocaleString()}
                </span>
              </div>
            ))
          ) : (
            <div className="p-12 text-center text-gray-400 italic">
              No status data available.
            </div>
          )}
          {/* Detailed Stats Row */}
          <div className="p-6 grid grid-cols-3 gap-8 bg-gray-50/30">
            <div className="text-left">
              <p className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
                Paid Invoices
              </p>
              <p className="text-2xl font-black text-green-600">
                {metrics?.paidInvoices || 0}
              </p>
            </div>
            <div className="text-left border-l pl-8">
              <p className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
                Pending Invoices
              </p>
              <p className="text-2xl font-black text-orange-500">
                {metrics?.pendingInvoices || 0}
              </p>
            </div>
            <div className="text-left border-l pl-8">
              <p className="text-[10px] font-bold text-gray-400 uppercase tracking-widest">
                Overdue Invoices
              </p>
              <p className="text-2xl font-black text-red-500">
                {metrics?.overdueInvoices || 0}
              </p>
            </div>
          </div>
        </div>
      </section>

      {/* Recent Proforma Requests (Full Width) */}
      <section className="space-y-4">
        <h2 className="text-xl font-bold text-gray-900">
          Recent Proforma Requests
        </h2>
        <div className="border overflow-hidden rounded-none">
          <table className="w-full text-left">
            <thead className="bg-gray-50 border-b">
              <tr>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Title
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Category
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Status
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Deadline
                </th>
              </tr>
            </thead>
            <tbody className="bg-white divide-y">
              {proformaRequests?.data && proformaRequests.data.length > 0 ? (
                proformaRequests.data.map((request) => (
                  <tr
                    key={request.id}
                    className="hover:bg-gray-50 transition-colors"
                  >
                    <td className="px-6 py-5">
                      <div className="text-sm font-bold text-gray-900 uppercase tracking-tight">
                        {request.title}
                      </div>
                    </td>
                    <td className="px-6 py-5 text-sm font-medium text-gray-600">
                      {request.category}
                    </td>
                    <td className="px-6 py-5">
                      <Badge
                        variant="outline"
                        className="rounded-none border-gray-200 font-bold text-[10px] uppercase tracking-widest"
                      >
                        {request.status}
                      </Badge>
                    </td>
                    <td className="px-6 py-5 text-sm text-gray-500 font-medium">
                      {format(
                        new Date(request.submissionDeadline),
                        "MMM dd, yyyy",
                      )}
                    </td>
                  </tr>
                ))
              ) : (
                <tr>
                  <td
                    colSpan={4}
                    className="px-6 py-20 text-center text-gray-400 italic font-medium uppercase tracking-widest text-[10px]"
                  >
                    No proforma requests recorded.
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </div>
      </section>

      {/* Pending Verification (Full Width) */}
      <section className="space-y-4">
        <h2 className="text-xl font-bold text-gray-900">
          Pending Verification
        </h2>
        <div className="border overflow-hidden rounded-none">
          <table className="w-full text-left">
            <thead className="bg-gray-50 border-b">
              <tr>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Invoice Number
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Customer
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Amount
                </th>
                <th className="px-6 py-4 text-[10px] font-bold text-gray-500 uppercase tracking-widest">
                  Issue Date
                </th>
              </tr>
            </thead>
            <tbody className="bg-white divide-y">
              {scannedInvoices && scannedInvoices.length > 0 ? (
                scannedInvoices.map((invoice) => (
                  <tr
                    key={invoice.id}
                    className="hover:bg-gray-50 transition-colors"
                  >
                    <td className="px-6 py-5 text-sm font-bold text-gray-900">
                      {invoice.invoiceNumber}
                    </td>
                    <td className="px-6 py-5 text-sm text-gray-600">
                      {invoice.customerName}
                    </td>
                    <td className="px-6 py-5 text-sm font-bold text-gray-900">
                      {formatCurrency(invoice.amount)}
                    </td>
                    <td className="px-6 py-5 text-sm text-gray-500">
                      {new Date(invoice.issueDate).toLocaleDateString()}
                    </td>
                  </tr>
                ))
              ) : (
                <tr>
                  <td
                    colSpan={4}
                    className="px-6 py-20 text-center text-gray-400 italic"
                  >
                    No invoices are currently pending verification.
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </div>
      </section>
        </>
      )}
    </div>
  );
}