import { ORDER_STATUS_LABELS } from '@dukang/shared-types';
import ExcelJS from 'exceljs';
import * as fs from 'fs';
import * as path from 'path';
import PDFDocument from 'pdfkit';

const EXPORT_HEADERS = [
  '订单号',
  '下单时间',
  '状态',
  '商品',
  '规格',
  '数量',
  '实付',
  '好客权益',
  '收货人',
  '手机',
  '收货地址',
] as const;

export type OrderExportRow = {
  orderNo: string;
  createdAt: string;
  status: string;
  productName: string;
  productSpec: string;
  quantity: number;
  payAmount: number;
  benefitBrief: string;
  receiverName: string;
  receiverPhone: string;
  address: string;
};

function formatBenefitBrief(order: {
  benefitAmount?: { toString(): string } | number | null;
  benefitCoupon?: {
    totalAmount?: { toString(): string } | number;
    usedAmount?: { toString(): string } | number;
    balance?: { toString(): string } | number;
  } | null;
}): string {
  const coupon = order.benefitCoupon;
  if (coupon) {
    return `总额¥${Number(coupon.totalAmount).toFixed(2)} / 已用¥${Number(coupon.usedAmount).toFixed(2)} / 余¥${Number(coupon.balance).toFixed(2)}`;
  }
  if (order.benefitAmount != null) return `¥${Number(order.benefitAmount).toFixed(2)}`;
  return '';
}

/** 导出给运营看的时间：按上海时区，避免 toISOString() 落成 UTC（少 8 小时） */
function formatShanghaiDateTime(value: Date): string {
  return value.toLocaleString('sv-SE', { timeZone: 'Asia/Shanghai' });
}

export function formatExportDateTime(value?: Date | null): string {
  if (!value) return '';
  return formatShanghaiDateTime(value);
}

export function mapOrderToExportRow(order: {
  orderNo: string;
  createdAt: Date;
  status: string;
  productName: string;
  productSpec: string;
  quantity: number;
  payAmount: { toString(): string } | number;
  benefitAmount?: { toString(): string } | number | null;
  receiverName: string;
  receiverPhone: string;
  receiverProvince: string;
  receiverCity: string;
  receiverDistrict: string;
  receiverAddress: string;
  benefitCoupon?: {
    totalAmount?: { toString(): string } | number;
    usedAmount?: { toString(): string } | number;
    balance?: { toString(): string } | number;
  } | null;
  deliveryType?: string;
}): OrderExportRow {
  const isOnSite =
    order.deliveryType === 'ON_SITE_PICKUP' ||
    order.receiverAddress === '现场取货' ||
    order.receiverAddress === '现场提货' ||
    (order.receiverProvince === '现场' && order.receiverCity === '现场');
  const address = isOnSite
    ? '现场取货'
    : `${order.receiverProvince}${order.receiverCity}${order.receiverDistrict}${order.receiverAddress}`;
  return {
    orderNo: order.orderNo,
    createdAt: formatExportDateTime(order.createdAt),
    status: ORDER_STATUS_LABELS[order.status] || order.status,
    productName: order.productName,
    productSpec: order.productSpec,
    quantity: order.quantity,
    payAmount: Number(order.payAmount),
    benefitBrief: formatBenefitBrief(order),
    receiverName: order.receiverName,
    receiverPhone: order.receiverPhone,
    address,
  };
}

export function rowToCells(row: OrderExportRow): string[] {
  return [
    row.orderNo,
    row.createdAt,
    row.status,
    row.productName,
    row.productSpec,
    String(row.quantity),
    row.payAmount.toFixed(2),
    row.benefitBrief,
    row.receiverName,
    row.receiverPhone,
    row.address,
  ];
}

function resolvePdfFontPath(): string {
  const candidates = [
    process.env.EXPORT_PDF_FONT_PATH,
    path.join(process.cwd(), 'assets', 'fonts', 'NotoSansSC-Regular.otf'),
    path.join(process.cwd(), 'assets', 'fonts', 'simhei.ttf'),
    path.join(process.cwd(), 'assets', 'fonts', 'msyh.ttc'),
    path.join(process.cwd(), 'dist', 'assets', 'fonts', 'simhei.ttf'),
    '/usr/share/fonts/truetype/noto/NotoSansCJK-Regular.ttc',
    '/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc',
    'C:\\Windows\\Fonts\\simhei.ttf',
    'C:\\Windows\\Fonts\\msyh.ttc',
  ].filter(Boolean) as string[];

  for (const candidate of candidates) {
    if (fs.existsSync(candidate)) return candidate;
  }
  throw new Error('未找到可用于 PDF 的中文字体，请将字体文件放到 server/dukang-api/assets/fonts/');
}

export async function buildOrdersXlsx(rows: OrderExportRow[]): Promise<Buffer> {
  const workbook = new ExcelJS.Workbook();
  const sheet = workbook.addWorksheet('订单');
  sheet.addRow([...EXPORT_HEADERS]);
  for (const row of rows) {
    sheet.addRow(rowToCells(row));
  }
  sheet.columns.forEach((col) => {
    col.width = 16;
  });
  sheet.getColumn(4).width = 22;
  sheet.getColumn(8).width = 36;
  sheet.getColumn(11).width = 36;
  const buffer = await workbook.xlsx.writeBuffer();
  return Buffer.from(buffer);
}

export async function buildOrdersPdf(rows: OrderExportRow[]): Promise<Buffer> {
  const fontPath = resolvePdfFontPath();
  const chunks: Buffer[] = [];

  return new Promise((resolve, reject) => {
    const doc = new PDFDocument({
      size: 'A4',
      layout: 'landscape',
      margin: 24,
      bufferPages: true,
    });
    doc.on('data', (chunk) => chunks.push(chunk as Buffer));
    doc.on('end', () => resolve(Buffer.concat(chunks)));
    doc.on('error', reject);

    doc.registerFont('zh', fontPath);
    doc.font('zh');

    const pageWidth = doc.page.width - doc.page.margins.left - doc.page.margins.right;
    const colWidths = [72, 78, 48, 88, 64, 32, 48, 110, 48, 72, 120];
    const scale = pageWidth / colWidths.reduce((sum, w) => sum + w, 0);
    const widths = colWidths.map((w) => w * scale);
    const rowHeight = 28;
    const fontSize = 7;
    let y = doc.page.margins.top;

    const drawRow = (cells: string[], isHeader = false) => {
      let x = doc.page.margins.left;
      const height = isHeader ? 24 : rowHeight;
      if (y + height > doc.page.height - doc.page.margins.bottom) {
        doc.addPage({ size: 'A4', layout: 'landscape', margin: 24 });
        y = doc.page.margins.top;
      }
      doc.fontSize(isHeader ? 8 : fontSize);
      cells.forEach((cell, index) => {
        doc.rect(x, y, widths[index], height).stroke('#dddddd');
        doc.text(cell || '', x + 2, y + 4, {
          width: widths[index] - 4,
          height: height - 6,
          lineBreak: true,
        });
        x += widths[index];
      });
      y += height;
    };

    drawRow([...EXPORT_HEADERS], true);
    for (const row of rows) {
      drawRow(rowToCells(row));
    }

    doc.end();
  });
}

export function buildExportFilename(format: 'xlsx' | 'pdf', count: number): string {
  const stamp = formatShanghaiDateTime(new Date()).slice(0, 10);
  return `订单导出_${stamp}_${count}条.${format}`;
}