import * as XLSX from 'xlsx';
import type { MonitoringVehicle } from './types';

interface ExportContext {
  date: string;
  sortBy: 'today' | 'total';
}

const HEADERS = [
  '状态', '车牌号', '客户', '业务部门', '项目', '租赁状态',
  '运营区域', '今日里程(km)', '累计里程(km)',
] as const;

function statusLabel(v: MonitoringVehicle): string {
  if (!v.isDataSynced) return '未对接';
  return v.isOnline ? '在线' : '离线';
}

function mileageCell(v: MonitoringVehicle, kind: 'today' | 'total'): string | number {
  if (!v.isDataSynced) return '未对接';
  if (kind === 'today') return Math.max(0, Math.round(v.dailyKm || 0));
  return v.totalKm != null ? Math.round(v.totalKm) : '未对接';
}

export function exportMileageXlsx(vehicles: MonitoringVehicle[], ctx: ExportContext): void {
  const data: (string | number)[][] = [
    [...HEADERS],
    ...vehicles.map(v => [
      statusLabel(v),
      v.plate,
      v.customer || '',
      v.department || '',
      v.project || '',
      v.rentStatus || '',
      v.region || '',
      mileageCell(v, 'today'),
      mileageCell(v, 'total'),
    ]),
  ];

  const ws = XLSX.utils.aoa_to_sheet(data);

  ws['!cols'] = [
    { wch: 8 },   // 状态
    { wch: 12 },  // 车牌号
    { wch: 28 },  // 客户
    { wch: 14 },  // 业务部门
    { wch: 16 },  // 项目
    { wch: 10 },  // 租赁状态
    { wch: 12 },  // 运营区域
    { wch: 14 },  // 今日里程
    { wch: 14 },  // 累计里程
  ];

  ws['!freeze'] = { xSplit: 0, ySplit: 1 } as never;

  // 表头样式（在客户端 SheetJS 社区版仅基本样式生效）
  for (let c = 0; c < HEADERS.length; c++) {
    const ref = XLSX.utils.encode_cell({ r: 0, c });
    if (ws[ref]) {
      (ws[ref] as { s?: unknown }).s = {
        font: { bold: true, color: { rgb: 'FFFFFF' } },
        fill: { fgColor: { rgb: '2563EB' } },
        alignment: { horizontal: 'center', vertical: 'center' },
      };
    }
  }

  const wb = XLSX.utils.book_new();
  XLSX.utils.book_append_sheet(wb, ws, '里程明细');

  const now = new Date();
  const y = now.getFullYear();
  const m = String(now.getMonth() + 1).padStart(2, '0');
  const d = String(now.getDate()).padStart(2, '0');
  const hh = String(now.getHours()).padStart(2, '0');
  const mm = String(now.getMinutes()).padStart(2, '0');
  const dateTag = ctx.date ? ctx.date.replace(/-/g, '') : `${y}${m}${d}`;
  const filename = `里程看板_${dateTag}_${hh}${mm}_${ctx.sortBy === 'today' ? '今日' : '累计'}.xlsx`;
  XLSX.writeFile(wb, filename);
}