From 8740fafca2e517dfdaff379131735c1a050d487f Mon Sep 17 00:00:00 2001
From: saji <9110284+kschamplin@users.noreply.github.com>
Date: Wed, 10 May 2023 13:58:46 -0500
Subject: [PATCH] added session addr stuff

---
 gen_skylab.go   | 38 ++++++++++++++++++++++++++------------
 xbee/session.go | 30 ++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/gen_skylab.go b/gen_skylab.go
index 2d8adf8..d313eff 100644
--- a/gen_skylab.go
+++ b/gen_skylab.go
@@ -11,22 +11,36 @@ import (
 type Field interface {
 	Name() string
 
-}
-type PacketField struct {
-	Name string
-	Type string
-	Units string
-	Conversion float32
+	Size() int // the size of the data.
+	
+	// returns something like
+	// 	AuxVoltage uint16
+	// used inside the packet struct
+	Embed() string
+	
+	// returns 
+	Marshal() string
+	Decode() string
 }
 
+// this is a standard field, not a bitfield.
+type DataField struct {
+	Name string
+	Type string
+	Units string // mostly for documentation
+	Conversion float32 
+}
+
+
+// a PacketDef is a full can packet.
 type PacketDef struct {
 	Name string
 	Description string
 	Id uint32
 	BigEndian bool
-	data: []PacketField
-
+	data: []Field
 }
+
 // we need to generate bitfield types.
 // packet structs per each packet
 // constancts for packet IDs or a map.
@@ -46,8 +60,8 @@ it also needs a json marshalling.
 
 	func (b *BMSMeasurement)MarshalPacket() ([]byte, error) {
 		pkt := make([]byte, b.Size())
-		binary.LittleEndian.PutUint16(b.BatteryVoltage * 0.01)
-		binary.LittleEndian.PutUint16(b.AuxVoltage * 0.001)
+		binary.LittleEndian.PutUint16(pkt[0:], b.BatteryVoltage * 0.01)
+		binary.LittleEndian.PutUint16(pkt[2:],b.AuxVoltage * 0.001)
 		binary.LittleEndian.PutFloat32(b.Current) // TODO: make float function
 	}
 
@@ -64,7 +78,7 @@ it also needs a json marshalling.
 	}
 
 	func (b *BMSMeasurement) String() string {
-		return 'blah blah"
+		return "blah blah"
 	}
 
 we also need some kind of mechanism to lookup data type.
@@ -74,4 +88,4 @@ we also need some kind of mechanism to lookup data type.
 		// insert really massive switch case statement here.
 	}
 
-*/
\ No newline at end of file
+*/
diff --git a/xbee/session.go b/xbee/session.go
index a6802b2..73605df 100644
--- a/xbee/session.go
+++ b/xbee/session.go
@@ -9,6 +9,7 @@ package xbee
 
 import (
 	"bufio"
+	"encoding/binary"
 	"errors"
 	"fmt"
 	"io"
@@ -25,6 +26,19 @@ import (
 // TODO: implement net.Conn for Session/Conn. We are missing LocalAddr, RemoteAddr,
 // and Deadline related methods.
 
+// XBeeAddr is an XBee device address.
+type XBeeAddr uint64
+
+func (addr XBeeAddr)String() string {
+	return fmt.Sprintf("%X", uint64(addr))
+}
+
+
+func (addr XBeeAddr) Network() string {
+	return "xbee"
+}
+
+
 // Session represents a connection to a locally-attached XBee. The connection can be through
 // serial/USB or TCP/IP depending on what is supported by the device.
 // Session implements the net.Conn interface, so it can be used anywhere a net.Conn can be used.
@@ -137,6 +151,8 @@ func (sess *Session) Write(p []byte) (int, error) {
 
 }
 
+
+// internal function used by Conn to write data to a specific address.
 func (sess *Session) writeAddr(p []byte, dest uint64) (n int, err error) {
 
 	idx, ch, err := sess.ct.GetMark()
@@ -228,6 +244,20 @@ func (sess *Session) Close() error {
 	return sess.ioDev.Close()
 }
 
+
+func (sess *Session) LocalAddr() XBeeAddr {
+	// TODO: should we get this once at the start? and then just store it?
+	sh, _ := sess.ATCommand([2]rune{'S', 'H'}, nil, false)
+	sl, _ := sess.ATCommand([2]rune{'S', 'L'}, nil, false)
+
+	addr := uint64(binary.BigEndian.Uint32(sh)) << 32 & uint64(binary.BigEndian.Uint32(sl))
+	return  XBeeAddr(addr)
+}
+
+func (sess *Session) RemoteAddr() XBeeAddr {
+	return 0xFFFF
+}
+
 // Conn is a connection to a specific remote XBee. Conn allows for the user to
 // contact one Xbee for point-to-point communications. This enables ACK packets
 // for reliable transmission.