// components/GroupReport.tsx
// Client component for group report table — sortable, exportable.

"use client";

import { useState } from "react";
import Link from "next/link";
import type { YsterbaardGroup, YsterbaardCompany } from "@/lib/types";

interface Props {
  group: YsterbaardGroup;
  companies: YsterbaardCompany[];
}

type SortKey = "enterprise_name" | "enterprise_no" | "sars_tax_number" | "sars_vat_no" | "sars_paye_no" | "enterprise_status";

export default function GroupReport({ group, companies }: Props) {
  const [sortKey, setSortKey] = useState<SortKey>("enterprise_name");
  const [sortDir, setSortDir] = useState<"asc" | "desc">("asc");

  const sorted = [...companies].sort((a, b) => {
    const av = String((a[sortKey] ?? "") || "");
    const bv = String((b[sortKey] ?? "") || "");
    const cmp = av.localeCompare(bv);
    return sortDir === "asc" ? cmp : -cmp;
  });

  function toggleSort(k: SortKey) {
    if (k === sortKey) {
      setSortDir(d => d === "asc" ? "desc" : "asc");
    } else {
      setSortKey(k);
      setSortDir("asc");
    }
  }

  function sortIcon(k: SortKey) {
    if (k !== sortKey) return "↕";
    return sortDir === "asc" ? "↑" : "↓";
  }

  function exportCSV() {
    const headers = ["Enterprise No", "Company Name", "Income Tax", "VAT", "PAYE", "Status", "Edit", "View"];
    const rows = sorted.map(c => [
      c.enterprise_no || "",
      c.enterprise_name || "",
      c.sars_tax_number || "",
      c.sars_vat_no || "",
      c.sars_paye_no || "",
      c.enterprise_status || "",
      `/companies/${c.id}`,
      `/companies/${c.id}`,
    ]);
    const csv = [headers, ...rows]
      .map(r => r.map(cell => `"${String(cell).replace(/"/g, '""')}"`).join(","))
      .join("\n");
    const blob = new Blob([csv], { type: "text/csv" });
    const url = URL.createObjectURL(blob);
    const a = document.createElement("a");
    a.href = url;
    a.download = `${group.name}-report-${new Date().toISOString().slice(0, 10)}.csv`;
    a.click();
    URL.revokeObjectURL(url);
  }

  const stats = {
    total: companies.length,
    withTax: companies.filter(c => c.sars_tax_number).length,
    withVat: companies.filter(c => c.sars_vat_no).length,
    withPaye: companies.filter(c => c.sars_paye_no).length,
    inBusiness: companies.filter(c => (c.enterprise_status || "").toLowerCase().includes("business")).length,
  };

  return (
    <div className="space-y-6">
      {/* Stats cards */}
      <div className="grid grid-cols-2 md:grid-cols-5 gap-3">
        <StatCard label="Total Companies" value={stats.total} />
        <StatCard label="In Business" value={stats.inBusiness} highlight={stats.inBusiness > 0 ? "green" : "muted"} />
        <StatCard label="With Tax #" value={stats.withTax} highlight={stats.withTax === stats.total ? "green" : stats.withTax === 0 ? "red" : "muted"} />
        <StatCard label="With VAT #" value={stats.withVat} highlight={stats.withVat === stats.total ? "green" : stats.withVat === 0 ? "red" : "muted"} />
        <StatCard label="With PAYE #" value={stats.withPaye} highlight={stats.withPaye === stats.total ? "green" : stats.withPaye === 0 ? "red" : "muted"} />
      </div>

      {/* Toolbar */}
      <div className="flex items-center justify-between gap-3">
        <p className="text-sm text-muted">
          Showing {sorted.length} of {companies.length} compan{companies.length === 1 ? "y" : "ies"}
        </p>
        <button
          onClick={exportCSV}
          className="text-xs px-4 py-2 rounded border border-border bg-surface text-fg font-semibold hover:border-accent hover:text-accent transition-colors"
        >
          ⬇ Export CSV
        </button>
      </div>

      {/* Report table */}
      {sorted.length === 0 ? (
        <div className="bg-surface border border-border rounded-lg p-12 text-center text-muted">
          No companies are currently in the {group.name} group.
        </div>
      ) : (
        <div className="bg-surface border border-border rounded-lg overflow-hidden">
          <div className="overflow-x-auto">
            <table className="w-full text-sm">
              <thead className="bg-surface-warm text-muted text-xs uppercase tracking-wide">
                <tr>
                  <SortHeader label="Enterprise No" sortKey="enterprise_no" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <SortHeader label="Company Name" sortKey="enterprise_name" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <SortHeader label="Income Tax #" sortKey="sars_tax_number" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <SortHeader label="VAT #" sortKey="sars_vat_no" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <SortHeader label="PAYE #" sortKey="sars_paye_no" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <SortHeader label="Status" sortKey="enterprise_status" current={sortKey} dir={sortDir} onSort={toggleSort} icon={sortIcon} />
                  <th className="px-3 py-3 font-semibold text-right w-24">Edit</th>
                  <th className="px-3 py-3 font-semibold text-right w-24">View</th>
                </tr>
              </thead>
              <tbody className="divide-y divide-border bg-surface">
                {sorted.map(c => (
                  <tr key={c.id} className="hover:bg-surface-warm/50 transition-colors">
                    <td className="px-3 py-3 font-mono text-xs whitespace-nowrap">
                      {c.enterprise_no || <span className="text-muted italic">—</span>}
                    </td>
                    <td className="px-3 py-3">
                      <Link href={`/companies/${c.id}`} className="text-fg font-semibold hover:text-accent no-underline">
                        {c.enterprise_name || <span className="text-muted italic">—</span>}
                      </Link>
                    </td>
                    <td className="px-3 py-3 font-mono text-xs whitespace-nowrap">
                      {c.sars_tax_number || <span className="text-muted italic">—</span>}
                    </td>
                    <td className="px-3 py-3 font-mono text-xs whitespace-nowrap">
                      {c.sars_vat_no || <span className="text-muted italic">—</span>}
                    </td>
                    <td className="px-3 py-3 font-mono text-xs whitespace-nowrap">
                      {c.sars_paye_no || <span className="text-muted italic">—</span>}
                    </td>
                    <td className="px-3 py-3">
                      <span className={`text-xs px-2 py-0.5 rounded font-semibold ${
                        (c.enterprise_status || "").toLowerCase().includes("business")
                          ? "bg-green-100 text-green-700"
                          : (c.enterprise_status || "").toLowerCase().includes("deregistered")
                            ? "bg-red-100 text-red-600"
                            : "bg-yellow-100 text-yellow-700"
                      }`}>
                        {c.enterprise_status || "—"}
                      </span>
                    </td>
                    <td className="px-3 py-3 text-right">
                      <Link
                        href={`/companies/${c.id}`}
                        className="text-xs px-2.5 py-1 rounded border border-border bg-surface-warm text-fg no-underline hover:border-accent hover:text-accent transition-colors"
                      >
                        Edit
                      </Link>
                    </td>
                    <td className="px-3 py-3 text-right">
                      <Link
                        href={`/companies/${c.id}`}
                        className="text-xs font-semibold no-underline text-fg hover:text-accent"
                      >
                        View →
                      </Link>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        </div>
      )}
    </div>
  );
}

function StatCard({ label, value, highlight = "muted" }: { label: string; value: number; highlight?: "green" | "red" | "muted" }) {
  const colors = {
    green: "text-green-700",
    red: "text-red-600",
    muted: "text-fg",
  };
  return (
    <div className="bg-surface border border-border rounded-lg p-4">
      <p className="text-xs uppercase tracking-wide text-muted font-semibold">{label}</p>
      <p className={`text-2xl font-bold mt-1 ${colors[highlight]}`}>{value}</p>
    </div>
  );
}

function SortHeader({ label, sortKey, current, dir, onSort, icon }: {
  label: string;
  sortKey: SortKey;
  current: SortKey;
  dir: "asc" | "desc";
  onSort: (k: SortKey) => void;
  icon: (k: SortKey) => string;
}) {
  const isActive = current === sortKey;
  return (
    <th className="px-3 py-3 font-semibold">
      <button
        onClick={() => onSort(sortKey)}
        className={`flex items-center gap-1.5 text-xs uppercase tracking-wide hover:text-fg transition-colors ${
          isActive ? "text-fg" : "text-muted"
        }`}
      >
        {label}
        <span className="text-[10px] opacity-70">{icon(sortKey)}</span>
      </button>
    </th>
  );
}