import ExcelJS from 'exceljs'
import { saveAs } from 'file-saver'

interface ExportImageGroup {
  name: string
  urls: string[]
}

interface ExcelEmbedImage {
  buffer: ArrayBuffer
  width: number
  height: number
}

const IMAGE_PREVIEW_COLUMN_WIDTH = 25
const IMAGE_CELL_WIDTH_PX = 180
const POINTS_PER_PIXEL = 0.75

function calculateImageDisplaySize(width: number, height: number) {
  if (width <= 0 || height <= 0) {
    return {
      width: IMAGE_CELL_WIDTH_PX,
      height: IMAGE_CELL_WIDTH_PX,
    }
  }

  const scale = IMAGE_CELL_WIDTH_PX / width
  return {
    width: IMAGE_CELL_WIDTH_PX,
    height: Math.max(1, Math.round(height * scale)),
  }
}

function calculateImageRowHeightPoints(imageHeightPx: number) {
  return Math.max(90, Math.round(imageHeightPx * POINTS_PER_PIXEL))
}

async function fetchExcelEmbedImage(url: string): Promise<ExcelEmbedImage> {
  const proxyUrl = `/api/taobao-detail-plus/image-proxy?url=${encodeURIComponent(url)}`
  const response = await fetch(proxyUrl, {
    method: 'GET',
    cache: 'no-store',
    credentials: 'same-origin',
  })

  if (!response.ok) {
    throw new Error(`Image proxy failed with ${response.status}`)
  }

  const width = Number(response.headers.get('x-image-width') || 0)
  const height = Number(response.headers.get('x-image-height') || 0)

  return {
    buffer: await response.arrayBuffer(),
    width,
    height,
  }
}

export async function exportTaobaoImagesToExcel(
  title: string,
  itemId: string,
  groups: ExportImageGroup[]
) {
  const workbook = new ExcelJS.Workbook()
  const worksheet = workbook.addWorksheet('商品图片明细')

  // 设置列宽
  worksheet.columns = [
    { header: '分区', key: 'group', width: 15 },
    { header: '序号', key: 'index', width: 10 },
    { header: '图片预览', key: 'image', width: IMAGE_PREVIEW_COLUMN_WIDTH },
    { header: '原始链接', key: 'url', width: 60 }
  ]

  // 设置表头样式
  worksheet.getRow(1).font = { bold: true }
  worksheet.getRow(1).alignment = { vertical: 'middle', horizontal: 'center' }

  let currentRow = 2

  for (const group of groups) {
    for (let i = 0; i < group.urls.length; i++) {
      const url = group.urls[i]
      const row = worksheet.addRow({
        group: i === 0 ? group.name : '',
        index: i + 1,
        url: url
      })

      row.height = 90

      try {
        const imageData = await fetchExcelEmbedImage(url)
        const displaySize = calculateImageDisplaySize(imageData.width, imageData.height)
        row.height = calculateImageRowHeightPoints(displaySize.height)

        const imageId = workbook.addImage({
          buffer: imageData.buffer,
          extension: 'png',
        })

        const imageAnchor = {
          tl: { col: 2, row: currentRow - 1 },
          ext: {
            width: displaySize.width,
            height: displaySize.height,
          },
          editAs: 'oneCell'
        } as any

        worksheet.addImage(imageId, imageAnchor)
      } catch (error) {
        console.error(`Failed to embed image: ${url}`, error)
        worksheet.getCell(currentRow, 3).value = '图片下载失败'
      }

      currentRow++
    }

    // 分组之间加个细微分隔
    if (group.urls.length > 0) {
      worksheet.addRow([])
      currentRow++
    }
  }

  // 垂直居中所有单元格
  worksheet.eachRow((row) => {
    row.alignment = { vertical: 'middle', horizontal: 'center' }
  })

  // 导出文件
  const buffer = await workbook.xlsx.writeBuffer()
  const blob = new Blob([buffer], { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' })
  saveAs(blob, `${itemId}_淘宝图片导出_${new Date().getTime()}.xlsx`)
}