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

package service

import (
	"fmt"
	"strings"
)

type usbPrintOpKind uint8

const (
	usbOpWrite usbPrintOpKind = iota
	usbOpFeed
	usbOpQRCode
	usbOpCut
)

type usbPrintOp struct {
	kind    usbPrintOpKind
	data    []byte
	count   int
	qrData  string
	qrWidth int
}

type usbTicketData struct {
	lotName, channelCode, plateNo string
	entryTime, slipNo, ticketNo   string
}

var (
	usbSizeNormal   = []byte{GS, '!', 0x00}
	usbDoubleWidth  = []byte{GS, '!', 0x10}
	usbFontA        = []byte{ESC, 'M', 0}
	usbFontB        = []byte{ESC, 'M', 1}
	usbDirectionOff = []byte{ESC, '{', 0}
)

func buildUSBTicketLayout(data usbTicketData) []usbPrintOp {
	var ops []usbPrintOp
	write := func(data ...byte) {
		ops = append(ops, usbPrintOp{kind: usbOpWrite, data: append([]byte(nil), data...)})
	}
	text := func(value string) {
		write(append([]byte(value), '\n')...)
	}
	feed := func(count int) {
		ops = append(ops, usbPrintOp{kind: usbOpFeed, count: count})
	}

	write(ESC, '@')
	write(usbDirectionOff...)
	write(ESC, 'a', 1)
	write(usbFontA...)
	write(usbDoubleWidth...)
	write(BoldOnCmd...)
	text("Parking Ticket")
	write(usbSizeNormal...)
	write(BoldOffCmd...)
	write(usbFontB...)
	text(data.lotName)
	text(strings.Repeat("-", 42))
	text("")
	text("PARK AT YOUR OWN RISK")

	write(ESC, 'a', 0)
	lotAndType := "A-General Car"
	if data.lotName != "" {
		lotAndType = data.lotName + " A-General Car"
	}
	text(lotAndType)
	write(usbFontA...)
	text("In-Time::" + data.entryTime)
	if data.channelCode != "" {
		text("InGate::" + data.channelCode)
	}
	text("Slip No::" + data.slipNo)
	if data.plateNo != "" {
		write(usbDoubleWidth...)
		write(BoldOnCmd...)
		text("Veh No::" + data.plateNo)
		write(usbSizeNormal...)
		write(BoldOffCmd...)
	}

	write(ESC, 'a', 1)
	feed(1)
	ops = append(ops, usbPrintOp{kind: usbOpQRCode, qrData: data.ticketNo, qrWidth: 12})
	feed(1)
	// Pos_EscQrcode can change text state. Restore the settings used by the
	// centered payment footer before writing any more text.
	write(usbDirectionOff...)
	write(ESC, 'a', 1)
	write(usbFontB...)
	text("SCAN AND PAY WITH NEW")
	text("THE CANADIA BANK APP")
	feed(8)
	ops = append(ops, usbPrintOp{kind: usbOpCut})

	return ops
}

type usbPrintDevice interface {
	Write([]byte) int
	FeedLines(int)
	QRCode(string, int) bool
	FullCut()
}

func executeUSBLayout(device usbPrintDevice, ops []usbPrintOp) error {
	for _, op := range ops {
		switch op.kind {
		case usbOpWrite:
			written := device.Write(op.data)
			if written != len(op.data) {
				return fmt.Errorf("USB打印短写: 写入%d/%d字节", written, len(op.data))
			}
		case usbOpFeed:
			device.FeedLines(op.count)
		case usbOpQRCode:
			if !device.QRCode(op.qrData, op.qrWidth) {
				return fmt.Errorf("USB二维码打印失败")
			}
		case usbOpCut:
			device.FullCut()
		}
	}
	return nil
}