package bds

import (
	"encoding/binary"
	"fmt"
	"wb/ut"
)

const (
	startStopBit byte = 0x7e
	startBit     byte = startStopBit
	stopBit      byte = startStopBit
	escChar      byte = 0x7d
	startStopAdd byte = 0x02
	escCharAdd   byte = 0x01
	uartBit      byte = 0x41
)

const msgMinLen = 9
const msgUartMinLen = msgMinLen + 3

var (
	mtSvcTermRegister            = []byte{0x81, 0x00}
	mtSvcCommonResponse          = []byte{0x80, 0x01}
	mtSvcQueryUart               = []byte{0x89, 0x00}
	mtSvcIo                      = []byte{0x85, 0x00}
	msSvcInitQueryUartSampleTime = []byte{0x89, 0x01}
	msSvcInitQueryUart           = []byte{0x89, 0x02}
	msSvcDeleteQueryUart         = []byte{0x89, 0x03}
)

const (
	msgTypeStart = 1
	msgHaedStart = 3
	msgSnStart   = 5
	msgBodyStart = 7
	mdbsStart    = 8
)

func parseMsg(msg []byte) string {
	msgType := ut.BytesToHexStr(msg[msgTypeStart:msgHaedStart])
	msgHeader := ut.BytesToHexStr(msg[msgHaedStart:msgSnStart])
	msgSn := ut.BytesToHexStr(msg[msgSnStart:msgBodyStart])
	msgBody := ut.BytesToHexStr(msg[msgBodyStart : len(msg)-2])
	return fmt.Sprint("TYPE=>", msgType, "HEAD=>", msgHeader, "SN=>", msgSn, "BODY=>", msgBody)
}

func getPosition(msg []byte) (x, y float64, ok bool) {
	bd := msg[msgBodyStart : len(msg)-2]
	if len(bd) < 16 {
		return 0, 0, false
	}
	//fmt.Println("len", len(bd))
	//fmt.Println("bx", bx)
	y = calcPosition(bd[8:12])
	//fmt.Println("by", by)
	x = calcPosition(bd[12:16])
	return x, y, true
}
func calcPosition(msg []byte) float64 {
	r64 := float64(binary.BigEndian.Uint32(msg)) / 1000000
	return r64
}
func getCheckSum(msg []byte) byte {
	var checkSum byte = 0
	for i := 1; i < len(msg)-2; i++ {
		checkSum = checkSum ^ msg[i]
	}
	return checkSum
}