From 7dc2d509c827411a313e99f22f08d275bbc534fa Mon Sep 17 00:00:00 2001
From: Pierre-Olivier Mercier <nemunaire@nemunai.re>
Date: Thu, 4 Feb 2021 00:58:03 +0100
Subject: [PATCH] Display key and hide checksum

---
 main.go | 94 ++++++++++++++++++++++++++++++++++++---------------------
 1 file changed, 59 insertions(+), 35 deletions(-)

diff --git a/main.go b/main.go
index 781023b..70307a1 100644
--- a/main.go
+++ b/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"bytes"
 	"flag"
+	"fmt"
 	"io"
 	"log"
 	"os"
@@ -27,7 +28,7 @@ func readSerial(s *serial.Port, c chan []byte) {
 		unread.Write(buf[:n])
 
 		for {
-			line, err := unread.ReadBytes('\n')
+			line, err := unread.ReadBytes(2)
 			if err == io.EOF {
 				if _, err = unread.Write(line); err != nil {
 					log.Println(err)
@@ -38,9 +39,31 @@ func readSerial(s *serial.Port, c chan []byte) {
 				break
 			}
 
-			c <- bytes.TrimRightFunc(line, func(r rune) bool {
-				return unicode.IsSpace(r) || unicode.IsControl(r)
-			})
+			c <- bytes.TrimRightFunc(line, unicode.IsControl)
+		}
+	}
+}
+
+func treatFrames(frames chan []byte) {
+	first := true
+	for {
+		frame := <-frames
+
+		// Skip the first frame because it's not complete
+		if first {
+			first = false
+			continue
+		}
+
+		for _, line := range bytes.Split(frame, []byte("\r\n")) {
+			key, horodate, data, err := treatLine(line)
+
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+
+			fmt.Println(key, horodate, data)
 		}
 	}
 }
@@ -55,11 +78,11 @@ func computeChecksum(area []byte) (checksum byte) {
 	return
 }
 
-func getHorodate(fields *[][]byte) (horodate time.Time, err error) {
-	if len(*fields) == 4 && len((*fields)[1]) == 13 {
-		horodate, err = time.Parse("060102150405", string((*fields)[1][1:]))
+func getHorodate(fields *[][]byte) (*time.Time, error) {
+	if (len(*fields) == 4 || string((*fields)[0]) == "DATE") && len((*fields)[1]) == 13 {
+		horodate, err := time.Parse("060102150405", string((*fields)[1][1:]))
 		if err != nil {
-			horodate = time.Now().Truncate(time.Second).UTC()
+			return nil, err
 		}
 
 		// Handle "saison"
@@ -71,36 +94,37 @@ func getHorodate(fields *[][]byte) (horodate time.Time, err error) {
 
 		// Mark field as treated
 		*fields = append((*fields)[:1], (*fields)[2:]...)
-	} else {
-		horodate = time.Now().Truncate(time.Second).UTC()
+
+		return &horodate, nil
 	}
 
-	return
+	return nil, nil
 }
 
-func treatLines(c chan []byte) {
-	for {
-		line := <-c
+func treatLine(line []byte) (key string, horodate *time.Time, data [][]byte, err error) {
+	line = bytes.TrimSpace(line)
 
-		if len(line) <= 1 {
-			continue
-		}
-
-		if computeChecksum(line[:len(line)-1]) != line[len(line)-1] {
-			log.Printf("BAD checksum on %s: calculated: %c\n", line, computeChecksum(line[:len(line)-1]))
-			continue
-		}
-
-		fields := bytes.Fields(line)
-
-		horodate, err := getHorodate(&fields)
-		if err != nil {
-			log.Println(err)
-			continue
-		}
-
-		log.Println(horodate, fields)
+	if len(line) <= 1 {
+		return
 	}
+
+	if computeChecksum(line[:len(line)-1]) != line[len(line)-1] {
+		log.Printf("BAD checksum on %s: calculated: %c\n", line, computeChecksum(line[:len(line)-1]))
+		return
+	}
+
+	fields := bytes.Fields(line)
+
+	key = string(fields[0])
+
+	horodate, err = getHorodate(&fields)
+	if err != nil {
+		return
+	}
+
+	data = fields[1 : len(fields)-1]
+
+	return
 }
 
 func main() {
@@ -127,9 +151,9 @@ func main() {
 		log.Fatal(err)
 	}
 
-	c := make(chan []byte)
-	go readSerial(s, c)
-	go treatLines(c)
+	frames := make(chan []byte)
+	go readSerial(s, frames)
+	go treatFrames(frames)
 
 	interrupt := make(chan os.Signal, 1)
 	signal.Notify(interrupt, os.Interrupt, syscall.SIGTERM)