my-iot/model.go

package main

import (
	"github.com/aws/aws-sdk-go/service/dynamodb"
	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
)

// Device struct for store device data from iot-item table
type Device struct {
	Device string `json:"device"`
	Name   string `json:"name"`
	Model  string `json:"model"`
}

// ItemInfo - create structs to hold info about new item
type ItemInfo struct {
	Firmware string `json:"firmware"`
	Sensor   string `json:"sensor"`
	Model    string `json:"model"`
	Name     string `json:"name"`
}

// SensorData to store all sensor's data
type SensorData struct {
	Battery      int     `json:"battery"`
	Light        int     `json:"light"`
	Conductivity float32 `json:"conductivity"`
	Moisture     float32 `json:"moisture"`
	Temperature  float32 `json:"temperature"`
	Humidity     float32 `json:"humidity"`
}

// Item is an item to generalize every IoT devices
type Item struct {
	Device    string     `json:"device"`
	Timestamp string     `json:"timestamp"`
	Info      ItemInfo   `json:"info"`
	Data      SensorData `json:"data"`
}

// History returns data in []Item
func (d Device) History(svc *dynamodb.DynamoDB, limit int64) ([]Item, error) {
	result, err := GetHistory(svc, d.Device, limit)
	var ev []Item
	if err != nil {
		return ev, err
	}
	for _, i := range result.Items {
		item := Item{}
		err = dynamodbattribute.UnmarshalMap(i, &item)
		item.Info.Name = d.Name
		item.Info.Model = d.Model
		if err != nil {
			return ev, err
		}
		ev = append(ev, item)
	}
	return ev, nil
}