"use strict";

const Promise = require("bluebird");
const matchValue = require("match-value");
const execBinary = require("../exec-binary");
const parseIECBytes = require("../parse-bytes-iec");
const createJSONParser = require("../text-parser-json");

function parseBoolean(value) {
	if (typeof value === "boolean") {
		// Newer versions of `lsblk` correctly use boolean values
		return value;
	} else {
		return matchValue(value, {
			0: false,
			1: true
		});
	}
}

function mapType(value) {
	return matchValue(value, {
		part: "partition",
		disk: "disk",
		loop: "loopDevice",
		rom: "disk",
		lvm: "partition"
	});
}

function mapSubType(value) {
	return matchValue(value, {
		part: null,
		disk: null,
		loop: null,
		rom: "readOnlyMedia",
		lvm: "lvm"
	});
}

function mapDeviceList(devices) {
	return devices.map((device) => {
		return {
			name: device.name,
			path: device.path,
			type: mapType(device.type),
			subType: mapSubType(device.type),
			mountpoint: device.mountpoint,
			deviceNumber: device["maj:min"],
			removable: parseBoolean(device.rm),
			readOnly: parseBoolean(device.ro),
			size: parseIECBytes(device.size),
			children: (device.children != null) ? mapDeviceList(device.children) : []
		};
	});
}

module.exports = function lsblk() {
	return Promise.try(() => {
		return execBinary("lsblk")
			.withFlags({ json: true, "output-all": true })
			.requireOnStdout(createJSONParser())
			.execute();
	}).then((output) => {
		return mapDeviceList(output.result.blockdevices);
	});
};