import { useCallback, useEffect, useRef, useState } from 'react';
import { ArrowLeft, Upload, Zap } from 'lucide-react';
import { fetchJson } from '../../auth/api-client';
import { useAuth } from '../../auth/useAuth';
import FeedbackFab from '../../components/FeedbackFab';
import RotatingFooterHint from '../../components/RotatingFooterHint';
import { PageFrame } from '../../components/ui/surface';
import { BatchTable } from './import-page/BatchTable';
import { RecordFilters } from './import-page/RecordFilters';
import { RecordTable } from './import-page/RecordTable';
import { SummaryKpis } from './import-page/SummaryKpis';
import { UploadDropzone } from './import-page/UploadDropzone';
import { UploadFeedback } from './import-page/UploadFeedback';
import type {
  BatchRow,
  ListItem,
  OverallRow,
  UploadResult,
  VehicleKindFilter,
} from './import-page/types';

function getJwt(): string | null {
  return sessionStorage.getItem('bi_jwt');
}

async function uploadFile(file: File): Promise<UploadResult> {
  const fd = new FormData();
  fd.append('file', file);
  const token = getJwt();
  const res = await fetch('/api/ele/import', {
    method: 'POST',
    headers: token ? { Authorization: `Bearer ${token}` } : {},
    body: fd,
  });
  const json = await res.json();
  if (!res.ok || !json.ok) throw new Error(json.message || `上传失败 (${res.status})`);
  return json as UploadResult;
}

export default function EleImportPage() {
  const { user } = useAuth();
  const [file, setFile] = useState<File | null>(null);
  const [uploading, setUploading] = useState(false);
  const [result, setResult] = useState<UploadResult | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [items, setItems] = useState<ListItem[]>([]);
  const [total, setTotal] = useState(0);
  const [overall, setOverall] = useState<OverallRow[]>([]);
  const [batches, setBatches] = useState<BatchRow[]>([]);
  const [filter, setFilter] = useState<VehicleKindFilter>('');
  const [batchFilter, setBatchFilter] = useState('');
  const [search, setSearch] = useState('');
  const [searchInput, setSearchInput] = useState('');
  const [dragOver, setDragOver] = useState(false);
  const inputRef = useRef<HTMLInputElement>(null);

  const reload = useCallback(async () => {
    const params = new URLSearchParams({ page: '1', limit: '50' });
    if (filter) params.set('kind', filter);
    if (batchFilter) params.set('batchId', batchFilter);
    if (search) params.set('search', search);
    const [list, agg, b] = await Promise.all([
      fetchJson<{ items: ListItem[]; total: number }>(`/api/ele/list?${params.toString()}`),
      fetchJson<{ overall: OverallRow[] }>(`/api/ele/aggregate`),
      fetchJson<{ items: BatchRow[] }>(`/api/ele/batches`),
    ]);
    setItems(list.items);
    setTotal(list.total);
    setOverall(agg.overall);
    setBatches(b.items);
  }, [filter, batchFilter, search]);

  useEffect(() => {
    reload().catch(e => console.error(e));
  }, [reload]);

  const handleUpload = async (selectedFile: File) => {
    setUploading(true);
    setError(null);
    setResult(null);
    try {
      const nextResult = await uploadFile(selectedFile);
      setResult(nextResult);
      await reload();
    } catch (e) {
      setError(e instanceof Error ? e.message : String(e));
    } finally {
      setUploading(false);
    }
  };

  const onPick = (selectedFile: File | null) => {
    setFile(selectedFile);
    if (selectedFile) handleUpload(selectedFile);
  };

  return (
    <PageFrame
      title="充电记录导入"
      subtitle="每日上传 xlsx，按订单编号去重，并自动匹配内部/外部车辆归属。"
      icon={Zap}
      eyebrow="ELECTRIC IMPORT"
      meta={user?.userName || '导入工作台'}
      actions={(
        <div className="flex items-center gap-2">
          <button
            onClick={() => {
              if (window.history.length > 1) window.history.back();
              else { window.location.hash = '#mileage'; }
            }}
            className="flex h-9 w-9 items-center justify-center rounded-xl border border-slate-100 bg-white text-slate-500 transition-colors hover:border-blue-200 hover:bg-blue-50 hover:text-blue-600"
            title="返回"
          >
            <ArrowLeft size={16} />
          </button>
          <button
            onClick={() => inputRef.current?.click()}
            className="inline-flex h-9 items-center gap-1.5 rounded-xl bg-slate-900 px-3 text-xs font-black text-white shadow-sm transition-colors hover:bg-slate-800"
          >
            <Upload size={14} />
            上传文件
          </button>
        </div>
      )}
    >
      <UploadDropzone
        inputRef={inputRef}
        file={file}
        uploading={uploading}
        dragOver={dragOver}
        onDragOver={(e) => { e.preventDefault(); setDragOver(true); }}
        onDragLeave={() => setDragOver(false)}
        onDrop={(e) => {
          e.preventDefault();
          setDragOver(false);
          const droppedFile = e.dataTransfer.files?.[0];
          if (droppedFile) onPick(droppedFile);
        }}
        onClick={() => inputRef.current?.click()}
        onInputChange={(e) => onPick(e.target.files?.[0] || null)}
      />

      <UploadFeedback
        result={result}
        error={error}
        onCloseResult={() => setResult(null)}
        onCloseError={() => setError(null)}
      />

      <SummaryKpis overall={overall} />

      <BatchTable
        batches={batches}
        batchFilter={batchFilter}
        onClearFilter={() => setBatchFilter('')}
        onSelectBatch={(batchId) => setBatchFilter(batchFilter === batchId ? '' : batchId)}
      />

      <section className="bg-white rounded-2xl border border-slate-100 shadow-sm overflow-hidden">
        <RecordFilters
          total={total}
          searchInput={searchInput}
          filter={filter}
          onSearchInputChange={(e) => setSearchInput(e.target.value)}
          onSearchKeyDown={(e) => { if (e.key === 'Enter') setSearch(searchInput); }}
          onFilterChange={setFilter}
        />
        <RecordTable items={items} />
      </section>

      <RotatingFooterHint className="pb-4" />
      <FeedbackFab module="ele" />
    </PageFrame>
  );
}