From 148c8c63cc36eaf7e983698d7bdc93307191001c Mon Sep 17 00:00:00 2001
From: Josh Spicer <josh@joshspicer.com>
Date: Sun, 26 Mar 2023 18:56:39 +0000
Subject: [PATCH] parse gps

---
 server/nodeRouter.go | 74 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 58 insertions(+), 16 deletions(-)

diff --git a/server/nodeRouter.go b/server/nodeRouter.go
index bd1024a..8f667ff 100644
--- a/server/nodeRouter.go
+++ b/server/nodeRouter.go
@@ -1,10 +1,10 @@
 package main
 
 import (
-	"fmt"
 	"io"
 	"log"
 	"net/http"
+	"strconv"
 	"strings"
 	"time"
 
@@ -28,8 +28,6 @@ func NodeRouter() *gin.Engine {
 
 func getNodeInfo(c *gin.Context) {
 
-	// ioWR := c.MustGet("ioWR").(io.ReadWriter)
-
 	// Make new IO ReadWriter
 	m, err := serial.New(serial.WithPort("/dev/ttyUSB2"), serial.WithBaud(115200))
 	if err != nil {
@@ -39,24 +37,68 @@ func getNodeInfo(c *gin.Context) {
 	defer m.Close()
 	var mio io.ReadWriter = m
 
-	modem := at.New(mio, at.WithTimeout(2*time.Second))
+	modem := at.New(mio, at.WithTimeout(5*time.Second))
 
-	info, err := modem.Command("I")
-	if err != nil {
-		c.String(http.StatusInternalServerError, fmt.Sprintf("Error getting modem info, %s", err.Error()))
-		return
+	var info string = "ERR"
+	var signalStrength string = "ERR"
+	var gpsLatitude float32 = 12.517572
+	var gpsLongitude float32 = -69.9649462
+
+	infoArr, err := modem.Command("I")
+	if err == nil {
+		info = infoArr[0]
 	}
-	signalStrength, err := modem.Command("+CSQ")
-	if err != nil {
-		c.String(http.StatusInternalServerError, fmt.Sprintf("Error getting signal strength, %s", err.Error()))
-		return
+
+	// +CSQ: 23,99
+	signalStrengthArr, err := modem.Command("+CSQ")
+	if err == nil {
+		signalStrength = strings.Join(signalStrengthArr, " ")
+	}
+
+	// +QGPSLOC: 174111.0,4736.8397N,12218.8860W,1.5,98.7,3,224.01,0.0,0.0,260323,05
+	gpsLocationArr, err := modem.Command("+QGPSLOC?")
+	if err == nil {
+		// Convert AT latitude and longitude response
+		var tmpLatitude = convertGpsLocation(gpsLocationArr[1])
+		var tmpLongitude = convertGpsLocation(gpsLocationArr[2])
+
+		if tmpLatitude != -1 && tmpLongitude != -1 {
+			gpsLatitude = tmpLatitude
+			gpsLongitude = tmpLongitude
+		}
 	}
 
 	c.JSON(http.StatusOK, gin.H{
 		"modemInfo":          info[0],
-		"signal":             strings.Join(signalStrength, " "),
-		"accessoriesBattery": -1,          // Mock
-		"gpsLatitude":        12.517572,   // Mock
-		"gpsLongitude":       -69.9649462, // Mock
+		"signal":             signalStrength,
+		"accessoriesBattery": -1, // Mock
+		"gpsLatitude":        gpsLatitude,
+		"gpsLongitude":       gpsLongitude,
 	})
 }
+
+func convertGpsLocation(gpsLocation string) float32 {
+	// 4736.8397N
+	// 12218.8860W
+
+	// Remove and store the last character
+	compassDirection := gpsLocation[len(gpsLocation)-1:]
+	gpsLocation = gpsLocation[:len(gpsLocation)-1]
+
+	// Move the decimal point two places to the left
+	// 4736.8397 -> 47.368397
+	// 12218.8860 -> 122.18886
+	gpsLocation = gpsLocation[:len(gpsLocation)-2] + "." + gpsLocation[len(gpsLocation)-2:]
+	// If compass direction is South or West, make the number negative
+	if compassDirection == "S" || compassDirection == "W" {
+		gpsLocation = "-" + gpsLocation
+	}
+
+	// Convert to float
+	gpsLocationFloat, err := strconv.ParseFloat(gpsLocation, 32)
+	if err != nil {
+		log.Println(err)
+		return -1
+	}
+	return float32(gpsLocationFloat)
+}