lc_garage/internal/modules/printer/service/service.go

package service

import (
	"fmt"
	"os"
	"os/exec"
	"time"
	"wails-app/internal/dao"
	"wails-app/internal/global"
)

const sdkDllPath = `D:\lq\资料\停车场 道闸 车牌识别 收费机\票机自制\打印机\EMD807嵌入式热敏票据打印模组\5、SDK指令集\Win_SDK_Demo_2023_08_14\Win_SDK_Demo_2023_08_14\lib\x64\CsnPrinterLibs.dll`

type PrintService struct{}

func NewPrintService() *PrintService { return &PrintService{} }

func (s *PrintService) PrintTicket(printerID uint, lotName, channelCode, plateNo string, ticketID uint, ticketNo string) error {
	var printer dao.Printer
	if err := global.GVA_DB.First(&printer, printerID).Error; err != nil {
		return fmt.Errorf("打印机未配置: id=%d", printerID)
	}

	var err error
	var srl *SerialPrinter
	var usbHandle uintptr
	useCSN := false

	if len(printer.PortName) >= 3 && printer.PortName[:3] == "COM" {
		srl, err = NewSerialPrinter(printer.PortName, printer.BaudRate)
		if err == nil {
			defer srl.Close()
		}
	} else {
		err = InitCSN(sdkDllPath)
		if err != nil {
			return fmt.Errorf("加载 CSN DLL 失败: %w (path=%s)", err, sdkDllPath)
		}
		// 枚举初始化（C# Demo 在 initForm() 中调用，可能是必要的初始化步骤）
		Csn_EnumUSB()
		Csn_EnumPRN()
		// 尝试 OpenUSB → OpenPRN
		name := printer.PortName
		if name == "USB" || name == "auto" || name == "" {
			name = Csn_EnumUSB()
		}
		usbHandle, err = csn_OpenUSB(name)
		if err != nil {
			usbHandle, err = csn_OpenPRN(name)
		}
		if err != nil {
			return fmt.Errorf("打开打印机失败: %w (name=%s)", err, name)
		}
		useCSN = true
		csn_SetPort(usbHandle) // 激活端口！
		defer csn_Close(usbHandle)
	}

	now := time.Now().Format("02-01-2006 15:04:05")
	slipNo := fmt.Sprintf("%d", ticketID)

	if useCSN {
		// 构造 ESC/POS 数据 → 写成临时文件 → 调 32 位辅助工具打印
		var buf []byte
		add := func(b []byte) { buf = append(buf, b...) }
		add(InitCmd); add(AlignCenterCmd); add(DoubleHeightCmd); add(BoldOnCmd)
		add(ESCPOS_Text("PARKING TICKET"))
		add(BoldOffCmd); add(NormalCmd)
		add(ESCPOS_Text("")); add(ESCPOS_Text(lotName))
		add(ESCPOS_Text("A-General Car")); add(ESCPOS_Text(""))
		add(ESCPOS_Text("PARK AT YOUR OWN RISK"))
		add(ESCPOS_Text("================================"))
		add(AlignLeftCmd)
		add(ESCPOS_Text("In-Time::"+now))
		if channelCode != "" { add(ESCPOS_Text("InGate::"+channelCode)) }
		if plateNo != "" { add(ESCPOS_Text("Veh No::"+plateNo)) }
		add(ESCPOS_Text("================================"))
		add(ESCPOS_Text("Slip No::"+slipNo))
		add(ESCPOS_Text("================================"))
		add(AlignCenterCmd); add(ESCPOS_Text(""))
		add(ESCPOS_QRCode(ticketNo))
		add(ESCPOS_Text(""))
		add(ESCPOS_Text("SCAN AND PAY WITH"))
		add(ESCPOS_Text("NEW THE CANADIA BANK APP"))
		add(InitCmd); add(ESCPOS_Text("")); add(ESCPOS_Text("")); add(ESCPOS_Text(""))
		add(CutPaperCmd)
		// 先尝试 CSN DLL WriteData，失败则用 32 位辅助工具
		n := Csn_WriteData(buf)
		if n == 0 {
			tmp, _ := os.CreateTemp("", "ticket_*.bin")
			if tmp != nil {
				tmp.Write(buf); tmp.Close()
				exec.Command("build/bin/ticket-print.exe", printer.PortName, tmp.Name()).Run()
				os.Remove(tmp.Name())
			}
		}
		global.GVA_DB.Model(&printer).Update("status", "online")
		return nil
	}

	// Serial ESC/POS fallback
	write := func(data []byte) { srl.Write(data) }
	line32 := "================================"
	write(InitCmd); write(AlignCenterCmd); write(DoubleHeightCmd); write(BoldOnCmd)
	write(ESCPOS_Text("PARKING TICKET"))
	write(BoldOffCmd); write(NormalCmd)
	write(ESCPOS_Text("")); write(ESCPOS_Text(lotName))
	write(ESCPOS_Text("A-General Car")); write(ESCPOS_Text(""))
	write(ESCPOS_Text("PARK AT YOUR OWN RISK")); write(ESCPOS_Text(line32))
	write(AlignLeftCmd)
	write(ESCPOS_Text("In-Time::"+now))
	if channelCode != "" { write(ESCPOS_Text("InGate::"+channelCode)) }
	if plateNo != "" { write(ESCPOS_Text("Veh No::"+plateNo)) }
	write(ESCPOS_Text(line32)); write(ESCPOS_Text("Slip No::"+slipNo)); write(ESCPOS_Text(line32))
	write(AlignCenterCmd); write(ESCPOS_Text(""))
	write(ESCPOS_QRCode(ticketNo)); write(ESCPOS_Text(""))
	write(AlignCenterCmd)
	write(ESCPOS_Text("SCAN AND PAY WITH"))
	write(ESCPOS_Text("NEW THE CANADIA BANK APP"))
	write(InitCmd); write(ESCPOS_Text("")); write(ESCPOS_Text("")); write(ESCPOS_Text(""))
	write(CutPaperCmd)

	global.GVA_DB.Model(&printer).Update("status", "online")
	return nil
}