printerCentral/server/api/print/image.post.ts

// Endpoint para imprimir imágenes usando Jimp
import Jimp from 'jimp'
import { EposMessageBuilder } from '~/server/utils/eposBuilder'
import { buildSoapEnvelope, sendToPrinter, parsePrinterResponse } from '~/server/utils/printer'

export default defineEventHandler(async (event) => {
  try {
    const config = useRuntimeConfig()
    const body = await readBody(event)

    const {
      path,
      width,
      threshold = 128,
      mode = 'mono'
    } = body as {
      path?: string
      width?: number
      threshold?: number
      mode?: string
    }

    if (!path) {
      return {
        ok: false,
        error: 'path required'
      }
    }

    // Leer y procesar imagen
    const img = await Jimp.read(path)
    let targetWidth = width || img.bitmap.width
    if (targetWidth <= 0) targetWidth = img.bitmap.width

    const scale = targetWidth / img.bitmap.width
    const targetHeight = Math.max(1, Math.round(img.bitmap.height * scale))

    img.resize(targetWidth, targetHeight, Jimp.RESIZE_BILINEAR)
    img.grayscale()

    // Empaquetar bits MSB first por byte
    const bytesPerRow = Math.ceil(targetWidth / 8)
    const out = Buffer.alloc(bytesPerRow * targetHeight)
    let outIdx = 0

    for (let y = 0; y < targetHeight; y++) {
      let byte = 0
      let bit = 7
      let rowBytes = 0

      for (let x = 0; x < targetWidth; x++) {
        const idx = (y * targetWidth + x) * 4
        const rgba = img.bitmap.data
        const r = rgba[idx]
        const g = rgba[idx + 1]
        const b = rgba[idx + 2]
        const lum = 0.299 * r + 0.587 * g + 0.114 * b
        const isBlack = lum < threshold

        if (isBlack) byte |= (1 << bit)
        bit--

        if (bit < 0) {
          out[outIdx++] = byte
          rowBytes++
          byte = 0
          bit = 7
        }
      }

      // Rellenar bits restantes
      if (bit !== 7) {
        out[outIdx++] = byte
        rowBytes++
      }

      // Rellenar a bytes completos si es necesario
      while (rowBytes < bytesPerRow) {
        out[outIdx++] = 0
        rowBytes++
      }
    }

    const base64 = out.toString('base64')

    // Construir mensaje ePOS
    const builder = new EposMessageBuilder()
    builder.imageRaw({
      width: targetWidth,
      height: targetHeight,
      mode,
      base64
    })

    const soap = buildSoapEnvelope(builder.build())

    const result = await sendToPrinter(
      soap,
      config.printerHost,
      config.printerDeviceId,
      parseInt(config.printerTimeoutMs)
    )

    const { success, code } = parsePrinterResponse(result.data)

    return {
      ok: success,
      httpStatus: result.status,
      code,
      raw: result.data,
      width: targetWidth,
      height: targetHeight
    }
  } catch (err: any) {
    return {
      ok: false,
      error: err.message
    }
  }
})