consumptions.js

// Run a REST query and return the result as a consumption array

"use strict";

const jsonpointer = require("jsonpointer");

class Item {
	constructor(from, consumption, consumptionUnit) {
		this.from = from;
		this.consumption = consumption;
		this.consumptionUnit = consumptionUnit;
	}
	toString() {
		return this.from + ": " + this.consumption + " " + this.consumptionUnit;
	}
}

exports.prometheus = function (config) {
	const to = new Date();
	let from = new Date(to);
	from.setHours(to.getHours() - 23);
	from.setMinutes(0);
	from.setSeconds(0);
	from.setMilliseconds(0);
	const toTime = JSON.stringify(to).replace(/\"/g, "");
	const fromTime = JSON.stringify(from).replace(/\"/g, "");
	let query = "http://" + config.host + ":" + config.port + "/api/v1/query_range?query=increase(" + config.metric;
	if (config.tags && config.tags.length > 0) {
		query = query + "{";
		config.tags.forEach((t) => {
			query = query + t.tag + "=" + '"' + t.value + '"';
		});
		query = query + "}";
	}

	query = query + "[1h])&start=" + fromTime + "&end=" + toTime + "&step=3600";
	// console.log("Query: ", query);

	return import("node-fetch")
		.then(() => {
			return fetch(query, {
				headers: {
					//   Authorization: "Bearer " + tibberToken,
					"Content-Type": "application/json"
				},
				method: "GET",
				resolveWithFullResponse: true,
				followRedirect: false
			})
				.then((res) => {
					const body = JSON.parse(res.body);
					const arr = jsonpointer.get(body, "/data/result/0/values");
					const consumptionArr = !arr
						? []
						: arr.map((v) => {
								const time = jsonpointer.get(v, "/0");
								const value = jsonpointer.get(v, "/1");
								let from = new Date(time * 1000);
								from.setHours(from.getHours() - 1);
								const item = new Item(from, Math.round(value * 100) / 100, "kWh");
								return item;
						  });
					return {
						label: config.label,
						data: consumptionArr
					};
				})
				.catch((e) => {
					console.error("Failed to read from Prometheus: ", e);
				});
		})
		.catch((e) => {
			console.log("Import fetch error: " + e);
		});
};