import { createFileRoute, Link } from "@tanstack/react-router";
import { useEffect, useMemo, useState } from "react";
import { ProtectedLayout } from "@/components/protected-layout";
import { PageContainer, PageHeader } from "@/components/app-shell";
import { Card, CardContent } from "@/components/ui/card";
import { Input } from "@/components/ui/input";
import { Badge } from "@/components/ui/badge";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
import { supabase } from "@/integrations/supabase/client";
import { Receipt, Search } from "lucide-react";
import { formatCurrency, formatDate, statusBadgeClass } from "@/lib/format";

export const Route = createFileRoute("/invoices/")({
  component: () => (
    <ProtectedLayout>
      <InvoicesIndex />
    </ProtectedLayout>
  ),
});

function InvoicesIndex() {
  const [invoices, setInvoices] = useState<any[]>([]);
  const [loading, setLoading] = useState(true);
  const [q, setQ] = useState("");
  const [status, setStatus] = useState<string>("all");

  useEffect(() => {
    (async () => {
      const { data } = await supabase
        .from("invoices")
        .select("*, client:clients(id, name), case:cases(id, case_number, title)")
        .order("created_at", { ascending: false });
      setInvoices(data ?? []);
      setLoading(false);
    })();
  }, []);

  const filtered = useMemo(() => {
    return invoices.filter((i) => {
      if (status !== "all" && i.status !== status) return false;
      if (!q) return true;
      const s = q.toLowerCase();
      return (
        i.invoice_number?.toLowerCase().includes(s) ||
        i.client?.name?.toLowerCase().includes(s) ||
        i.case?.case_number?.toLowerCase().includes(s)
      );
    });
  }, [invoices, q, status]);

  const totals = useMemo(() => {
    const outstanding = filtered.reduce((s, i) => s + (Number(i.total) - Number(i.amount_paid)), 0);
    const paid = filtered.reduce((s, i) => s + Number(i.amount_paid), 0);
    return { outstanding, paid, count: filtered.length };
  }, [filtered]);

  return (
    <PageContainer>
      <PageHeader title="Invoices" description="All client invoices across the firm" />

      <div className="grid sm:grid-cols-3 gap-3 mb-5">
        <Stat label="Invoices" value={totals.count.toString()} />
        <Stat label="Outstanding A/R" value={formatCurrency(totals.outstanding)} />
        <Stat label="Collected" value={formatCurrency(totals.paid)} />
      </div>

      <div className="flex flex-col sm:flex-row gap-2 mb-4">
        <div className="relative flex-1">
          <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
          <Input className="pl-9" placeholder="Search by invoice #, client, case…" value={q} onChange={(e) => setQ(e.target.value)} />
        </div>
        <Select value={status} onValueChange={setStatus}>
          <SelectTrigger className="w-[180px]"><SelectValue /></SelectTrigger>
          <SelectContent>
            <SelectItem value="all">All statuses</SelectItem>
            <SelectItem value="draft">Draft</SelectItem>
            <SelectItem value="sent">Sent</SelectItem>
            <SelectItem value="paid">Paid</SelectItem>
            <SelectItem value="overdue">Overdue</SelectItem>
            <SelectItem value="void">Void</SelectItem>
          </SelectContent>
        </Select>
      </div>

      <Card className="border-border/60 overflow-hidden">
        <CardContent className="p-0">
          <table className="w-full text-sm">
            <thead className="bg-muted/50 text-xs uppercase tracking-wider text-muted-foreground">
              <tr>
                <th className="text-left px-4 py-3 font-medium">Invoice #</th>
                <th className="text-left px-4 py-3 font-medium">Client</th>
                <th className="text-left px-4 py-3 font-medium">Issued</th>
                <th className="text-left px-4 py-3 font-medium">Due</th>
                <th className="text-left px-4 py-3 font-medium">Status</th>
                <th className="text-right px-4 py-3 font-medium">Total</th>
                <th className="text-right px-4 py-3 font-medium">Balance</th>
              </tr>
            </thead>
            <tbody>
              {loading && <tr><td colSpan={7} className="text-center py-12 text-muted-foreground">Loading…</td></tr>}
              {!loading && filtered.length === 0 && (
                <tr><td colSpan={7} className="text-center py-12 text-muted-foreground">
                  <Receipt className="h-8 w-8 mx-auto mb-2 opacity-40" />
                  No invoices yet. Generate one from a Client or Case page.
                </td></tr>
              )}
              {filtered.map((i) => {
                const balance = Number(i.total) - Number(i.amount_paid);
                return (
                  <tr key={i.id} className="border-t hover:bg-muted/30">
                    <td className="px-4 py-3">
                      <Link to="/invoices/$invoiceId" params={{ invoiceId: i.id }} className="font-medium hover:text-primary">
                        {i.invoice_number}
                      </Link>
                    </td>
                    <td className="px-4 py-3">
                      {i.client ? (
                        <Link to="/clients/$clientId" params={{ clientId: i.client.id }} className="hover:text-primary">
                          {i.client.name}
                        </Link>
                      ) : "—"}
                    </td>
                    <td className="px-4 py-3 text-muted-foreground">{formatDate(i.issue_date)}</td>
                    <td className="px-4 py-3 text-muted-foreground">{formatDate(i.due_date)}</td>
                    <td className="px-4 py-3"><Badge variant="outline" className={statusBadgeClass(i.status)}>{i.status}</Badge></td>
                    <td className="px-4 py-3 text-right tabular-nums">{formatCurrency(i.total)}</td>
                    <td className="px-4 py-3 text-right tabular-nums font-medium">{formatCurrency(balance)}</td>
                  </tr>
                );
              })}
            </tbody>
          </table>
        </CardContent>
      </Card>
    </PageContainer>
  );
}

function Stat({ label, value }: { label: string; value: string }) {
  return (
    <Card className="border-border/60">
      <CardContent className="p-4">
        <div className="text-[10px] uppercase tracking-wider text-muted-foreground">{label}</div>
        <div className="font-serif text-2xl mt-1">{value}</div>
      </CardContent>
    </Card>
  );
}