"use client";

import type { WorkloadReport } from "@/lib/types";
import {
  BarChart,
  Bar,
  XAxis,
  YAxis,
  CartesianGrid,
  Tooltip,
  ResponsiveContainer,
  Legend,
} from "recharts";
import { Users, AlertTriangle, CheckCircle } from "lucide-react";

export function WorkloadTab({ data }: { data: WorkloadReport }) {
  const chartData = data.users.map((u, i) => ({
    name: `Nutzer ${i + 1}`,
    user_id: u.user_id,
    active_cases: u.active_cases,
    deadlines: u.deadlines,
    overdue: u.overdue,
    completed: u.completed,
  }));

  const totalCases = data.users.reduce((sum, u) => sum + u.active_cases, 0);
  const totalOverdue = data.users.reduce((sum, u) => sum + u.overdue, 0);
  const totalCompleted = data.users.reduce((sum, u) => sum + u.completed, 0);

  return (
    <div className="space-y-6">
      {/* Summary cards */}
      <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
        <div className="rounded-xl border border-neutral-200 bg-white p-5">
          <div className="flex items-center gap-2 text-sm text-neutral-500">
            <Users className="h-4 w-4" />
            Mitarbeiter
          </div>
          <p className="mt-2 text-2xl font-semibold text-neutral-900">
            {data.users.length}
          </p>
          <p className="mt-1 text-xs text-neutral-500">
            {totalCases} aktive Akten gesamt
          </p>
        </div>
        <div className="rounded-xl border border-neutral-200 bg-white p-5">
          <div className="flex items-center gap-2 text-sm text-neutral-500">
            <AlertTriangle className="h-4 w-4" />
            Überfällige Fristen
          </div>
          <p className="mt-2 text-2xl font-semibold text-red-600">
            {totalOverdue}
          </p>
        </div>
        <div className="rounded-xl border border-neutral-200 bg-white p-5">
          <div className="flex items-center gap-2 text-sm text-neutral-500">
            <CheckCircle className="h-4 w-4" />
            Erledigte Fristen
          </div>
          <p className="mt-2 text-2xl font-semibold text-emerald-600">
            {totalCompleted}
          </p>
        </div>
      </div>

      {/* Stacked bar chart */}
      <div className="rounded-xl border border-neutral-200 bg-white p-5">
        <h3 className="mb-4 text-sm font-medium text-neutral-900">
          Auslastung pro Mitarbeiter
        </h3>
        {chartData.length === 0 ? (
          <p className="py-8 text-center text-sm text-neutral-400">
            Keine Daten im gewählten Zeitraum
          </p>
        ) : (
          <ResponsiveContainer width="100%" height={300}>
            <BarChart data={chartData}>
              <CartesianGrid strokeDasharray="3 3" stroke="#e5e5e5" />
              <XAxis dataKey="name" tick={{ fontSize: 12 }} stroke="#a3a3a3" />
              <YAxis
                allowDecimals={false}
                tick={{ fontSize: 12 }}
                stroke="#a3a3a3"
              />
              <Tooltip
                contentStyle={{
                  border: "1px solid #e5e5e5",
                  borderRadius: 8,
                  fontSize: 13,
                }}
              />
              <Legend wrapperStyle={{ fontSize: 13 }} />
              <Bar
                dataKey="active_cases"
                name="Aktive Akten"
                stackId="work"
                fill="#171717"
                radius={[0, 0, 0, 0]}
              />
              <Bar
                dataKey="completed"
                name="Erledigt"
                stackId="deadlines"
                fill="#a3a3a3"
                radius={[0, 0, 0, 0]}
              />
              <Bar
                dataKey="overdue"
                name="Überfällig"
                stackId="deadlines"
                fill="#dc2626"
                radius={[4, 4, 0, 0]}
              />
            </BarChart>
          </ResponsiveContainer>
        )}
      </div>

      {/* Table */}
      <div className="rounded-xl border border-neutral-200 bg-white">
        <div className="border-b border-neutral-100 px-5 py-4">
          <h3 className="text-sm font-medium text-neutral-900">
            Übersicht pro Mitarbeiter
          </h3>
        </div>
        {data.users.length === 0 ? (
          <p className="px-5 py-8 text-center text-sm text-neutral-400">
            Keine Mitarbeiter mit zugewiesenen Akten
          </p>
        ) : (
          <div className="overflow-x-auto">
            <table className="w-full text-sm">
              <thead>
                <tr className="border-b border-neutral-100 text-left text-neutral-500">
                  <th className="px-5 py-3 font-medium">Mitarbeiter</th>
                  <th className="px-5 py-3 font-medium text-right">
                    Aktive Akten
                  </th>
                  <th className="px-5 py-3 font-medium text-right">Fristen</th>
                  <th className="px-5 py-3 font-medium text-right">
                    Überfällig
                  </th>
                  <th className="px-5 py-3 font-medium text-right">
                    Erledigt
                  </th>
                </tr>
              </thead>
              <tbody>
                {data.users.map((u, i) => (
                  <tr
                    key={u.user_id}
                    className="border-b border-neutral-50 last:border-b-0"
                  >
                    <td className="px-5 py-3 text-neutral-900">
                      Nutzer {i + 1}
                      <span className="ml-2 text-xs text-neutral-400">
                        {u.user_id.slice(0, 8)}...
                      </span>
                    </td>
                    <td className="px-5 py-3 text-right font-medium text-neutral-900">
                      {u.active_cases}
                    </td>
                    <td className="px-5 py-3 text-right text-neutral-600">
                      {u.deadlines}
                    </td>
                    <td className="px-5 py-3 text-right">
                      {u.overdue > 0 ? (
                        <span className="inline-flex items-center rounded-full bg-red-50 px-2 py-0.5 text-xs font-medium text-red-700">
                          {u.overdue}
                        </span>
                      ) : (
                        <span className="text-neutral-400">0</span>
                      )}
                    </td>
                    <td className="px-5 py-3 text-right text-emerald-600">
                      {u.completed}
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </div>
    </div>
  );
}