'use client';

import { useEffect, useState } from 'react';
import { useRouter } from 'next/navigation';
import { FlaskConical, Plus, FileDown, Pencil, Trash2, X } from 'lucide-react';
import Navbar from '@/components/Navbar';
import { api } from '@/lib/api';
import { DistributionPlanListItem } from '@/types';

const CURRENT_YEAR = new Date().getFullYear();
const YEAR_KEY = 'distributionYear';

export default function DistributionListPage() {
  const router = useRouter();
  const [year, setYear] = useState<number>(() => {
    if (typeof window !== 'undefined') {
      return parseInt(localStorage.getItem(YEAR_KEY) || String(CURRENT_YEAR), 10);
    }
    return CURRENT_YEAR;
  });
  const [plans, setPlans] = useState<DistributionPlanListItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [deleteError, setDeleteError] = useState<string | null>(null);

  const years = Array.from({ length: 5 }, (_, i) => CURRENT_YEAR + 1 - i);

  useEffect(() => {
    localStorage.setItem(YEAR_KEY, String(year));
    fetchPlans();
  }, [year]);

  const fetchPlans = async () => {
    setLoading(true);
    try {
      const res = await api.get(`/fertilizer/distribution/?year=${year}`);
      setPlans(res.data);
    } catch (e) {
      console.error(e);
    } finally {
      setLoading(false);
    }
  };

  const handleDelete = async (id: number) => {
    setDeleteError(null);
    try {
      await api.delete(`/fertilizer/distribution/${id}/`);
      setPlans(prev => prev.filter(p => p.id !== id));
    } catch (e) {
      console.error(e);
      setDeleteError('削除できませんでした。');
    }
  };

  const handlePdf = async (id: number, planName: string) => {
    try {
      const res = await api.get(`/fertilizer/distribution/${id}/pdf/`, { responseType: 'blob' });
      const url = URL.createObjectURL(res.data);
      const a = document.createElement('a');
      a.href = url;
      a.download = `distribution_${planName}.pdf`;
      a.click();
      URL.revokeObjectURL(url);
    } catch (e) {
      console.error(e);
    }
  };

  return (
    <div className="min-h-screen bg-gray-50">
      <Navbar />
      <main className="max-w-6xl mx-auto px-4 py-8">
        <div className="flex items-center justify-between mb-6">
          <div className="flex items-center gap-3">
            <FlaskConical className="h-7 w-7 text-green-700" />
            <h1 className="text-2xl font-bold text-gray-900">分配計画</h1>
          </div>
          <button
            onClick={() => router.push('/distribution/new')}
            className="flex items-center gap-2 px-4 py-2 bg-green-600 text-white rounded-md hover:bg-green-700 transition-colors text-sm font-medium"
          >
            <Plus className="h-4 w-4" />
            新規作成
          </button>
        </div>

        {/* 年度セレクタ */}
        <div className="flex items-center gap-3 mb-6">
          <label className="text-sm font-medium text-gray-700">年度:</label>
          <select
            value={year}
            onChange={e => setYear(Number(e.target.value))}
            className="border border-gray-300 rounded-md px-3 py-1.5 text-sm focus:outline-none focus:ring-2 focus:ring-green-500"
          >
            {years.map(y => (
              <option key={y} value={y}>{y}年</option>
            ))}
          </select>
        </div>

        {deleteError && (
          <div className="flex items-start gap-2 bg-red-50 border border-red-300 text-red-700 rounded-md px-4 py-3 mb-4 text-sm">
            <span className="flex-1">{deleteError}</span>
            <button onClick={() => setDeleteError(null)}><X className="h-4 w-4" /></button>
          </div>
        )}

        {loading ? (
          <p className="text-gray-500 text-sm">読み込み中...</p>
        ) : plans.length === 0 ? (
          <div className="text-center py-16 text-gray-400">
            <FlaskConical className="h-12 w-12 mx-auto mb-3 opacity-30" />
            <p className="text-lg font-medium mb-1">{year}年の分配計画はありません</p>
            <p className="text-sm mb-6">施肥計画を元に分配計画を作成できます</p>
            <button
              onClick={() => router.push('/distribution/new')}
              className="px-4 py-2 bg-green-600 text-white rounded-md hover:bg-green-700 text-sm"
            >
              + 新規作成
            </button>
          </div>
        ) : (
          <div className="bg-white rounded-lg shadow-sm border border-gray-200 overflow-hidden">
            <table className="min-w-full divide-y divide-gray-200">
              <thead className="bg-gray-50">
                <tr>
                  <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 uppercase">計画名</th>
                  <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 uppercase">施肥計画</th>
                  <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 uppercase">作物/品種</th>
                  <th className="px-4 py-3 text-right text-xs font-medium text-gray-500 uppercase">グループ数</th>
                  <th className="px-4 py-3 text-right text-xs font-medium text-gray-500 uppercase">圃場数</th>
                  <th className="px-4 py-3"></th>
                </tr>
              </thead>
              <tbody className="divide-y divide-gray-100">
                {plans.map(plan => (
                  <tr key={plan.id} className="hover:bg-gray-50">
                    <td className="px-4 py-3 text-sm font-medium text-gray-900">{plan.name}</td>
                    <td className="px-4 py-3 text-sm text-gray-600">{plan.fertilization_plan_name}</td>
                    <td className="px-4 py-3 text-sm text-gray-600">{plan.crop_name} / {plan.variety_name}</td>
                    <td className="px-4 py-3 text-sm text-gray-700 text-right">{plan.group_count}</td>
                    <td className="px-4 py-3 text-sm text-gray-700 text-right">{plan.field_count}</td>
                    <td className="px-4 py-3">
                      <div className="flex items-center justify-end gap-2">
                        <button
                          onClick={() => handlePdf(plan.id, plan.name)}
                          className="flex items-center gap-1 px-2.5 py-1.5 text-xs border border-gray-300 rounded hover:bg-gray-100 text-gray-700"
                          title="PDF出力"
                        >
                          <FileDown className="h-3.5 w-3.5" />
                          PDF
                        </button>
                        <button
                          onClick={() => router.push(`/distribution/${plan.id}/edit`)}
                          className="flex items-center gap-1 px-2.5 py-1.5 text-xs border border-blue-300 rounded hover:bg-blue-50 text-blue-700"
                          title="編集"
                        >
                          <Pencil className="h-3.5 w-3.5" />
                          編集
                        </button>
                        <button
                          onClick={() => handleDelete(plan.id)}
                          className="flex items-center gap-1 px-2.5 py-1.5 text-xs border border-red-300 rounded hover:bg-red-50 text-red-600"
                          title="削除"
                        >
                          <Trash2 className="h-3.5 w-3.5" />
                          削除
                        </button>
                      </div>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          </div>
        )}
      </main>
    </div>
  );
}