From 2844bd89d12cf17f62844ba68581ec6e57ba835c Mon Sep 17 00:00:00 2001
From: Pieter Hollander <git@pieterhollander.nl>
Date: Sun, 18 Feb 2024 15:10:37 +0100
Subject: [PATCH] Added documentation to Payload struct.

---
 main.go | 48 ++++++++++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 22 deletions(-)

diff --git a/main.go b/main.go
index 379ac62..9c153be 100644
--- a/main.go
+++ b/main.go
@@ -13,29 +13,33 @@ import (
 	_ "github.com/lib/pq"
 )
 
+// Payload struct
+// Dt1, Dt2, Rt1, Rt2 and G are meter readings
+// By making them pointers to int, they can be set to 'nil' when the reading has not changed.
+// This way, they are logged as NULL in the database when no change has happened, saving storage capacity.
 type Payload struct {
-	T   string `json:"t"`
-	Dt1 *int   `json:"dt1"`
-	Dt2 *int   `json:"dt2"`
-	Rt1 *int   `json:"rt1"`
-	Rt2 *int   `json:"rt2"`
-	D   int    `json:"d"`
-	R   int    `json:"r"`
-	F   int    `json:"f"`
-	Fl  int    `json:"fl"`
-	G   *int   `json:"g"`
-	V1  int    `json:"v1"`
-	V2  int    `json:"v2"`
-	V3  int    `json:"v3"`
-	C1  int    `json:"c1"`
-	C2  int    `json:"c2"`
-	C3  int    `json:"c3"`
-	D1  int    `json:"d1"`
-	D2  int    `json:"d2"`
-	D3  int    `json:"d3"`
-	R1  int    `json:"r1"`
-	R2  int    `json:"r2"`
-	R3  int    `json:"r3"`
+	T   string `json:"t"`   // Timestamp
+	Dt1 *int   `json:"dt1"` // Delivered / imported meter reading tariff 1 (kWh)
+	Dt2 *int   `json:"dt2"` // Delivered / imported tariff 2 (kWh)
+	Rt1 *int   `json:"rt1"` // Returned / exported tariff 1 (kWh)
+	Rt2 *int   `json:"rt2"` // Returned / exported tariff 2 (kWh)
+	D   int    `json:"d"`   // Delivering / importing (W)
+	R   int    `json:"r"`   // Returning / exporting (W)
+	F   int    `json:"f"`   // Failure (counter)
+	Fl  int    `json:"fl"`  // Failure long duration (counter)
+	G   *int   `json:"g"`   // Gas meter reading (l)
+	V1  int    `json:"v1"`  // Voltage L1 (V)
+	V2  int    `json:"v2"`  // Voltage L2 (V)
+	V3  int    `json:"v3"`  // Voltage L3 (V)
+	C1  int    `json:"c1"`  // Current L1 (A)
+	C2  int    `json:"c2"`  // Current L2 (A)
+	C3  int    `json:"c3"`  // Current L3 (A)
+	D1  int    `json:"d1"`  // Delivering / importing L1 (W)
+	D2  int    `json:"d2"`  // Delivering / importing L2 (W)
+	D3  int    `json:"d3"`  // Delivering / importing L3 (W)
+	R1  int    `json:"r1"`  // Returning / exporting L1 (W)
+	R2  int    `json:"r2"`  // Returning / exporting L2 (W)
+	R3  int    `json:"r3"`  // Returning / exporting L3 (W)
 }
 
 var db *sql.DB