package message

import (
	"fmt"
	"strings"
)

// CanetFrame USR-CANET200_V1.0.7 设备  以太网-CAN 透传协议帧(13字节)
type CanetFrame struct {
	FF      bool       //true-1扩展帧
	RTR     bool       //true-1远程帧
	CanLen  byte       //CAN帧数据长度[0,8]，CanData中有效数据字节数
	CanId   CanFrameId //CAN帧ID
	CanData []byte     //CAN帧数据，8字节
}

func NewCanetFrame(buf []byte) *CanetFrame {
	cf := &CanetFrame{}
	cf.Decode(buf)
	return cf
}
func (p *CanetFrame) Encode() []byte {
	buf := make([]byte, 0, 13)
	//canet200帧信息
	b1 := byte(0x00)
	if p.FF {
		b1 |= 0x80 //bit7
	}
	if p.RTR {
		b1 |= 0x40 //bit6
	}
	b1 |= p.CanLen & 0x0f
	buf = append(buf, b1)
	//CAN 帧ID
	buf = append(buf, p.CanId.ID1)
	buf = append(buf, p.CanId.ID2)
	buf = append(buf, p.CanId.ID3)
	buf = append(buf, p.CanId.ID4<<3)
	//CAN 帧数据
	if len(p.CanData) != 8 {
		panic("len(p.CanData)!=8")
	}
	buf = append(buf, p.CanData...)
	return buf
}
func (p *CanetFrame) Decode(buf []byte) {
	if len(buf) != 13 {
		panic("len(buf)!=13")
	}
	//
	p.FF = buf[0]&0x80 == 0x80
	p.RTR = buf[0]&0x40 == 0x40
	p.CanLen = buf[0] & 0x0f
	//1 2 3 4
	p.CanId.ID1 = buf[1]
	p.CanId.ID2 = buf[2]
	p.CanId.ID3 = buf[3]
	p.CanId.ID4 = buf[4] >> 3
	//
	p.CanData = buf[5:]
}
func (p *CanetFrame) String() string {
	sb := strings.Builder{}
	sb.WriteString(fmt.Sprintf("FF = %t, RTR = %t, CanLen = %d, ID1 = 0x%0x, ID2 = 0x%0x, ID3 = 0x%0x, ID4 = 0x%0x,", p.FF, p.RTR, p.CanLen,
		p.CanId.ID1, p.CanId.ID2, p.CanId.ID3, p.CanId.ID4))
	sb.WriteString("CanData = ")
	for _, d := range p.CanData {
		sb.WriteString(fmt.Sprintf(" 0x%0x ", d))
	}
	return sb.String()
}