MPlayer slave mode in Node.js

index.js

"use strict"

const execa = require("execa")
const { default: ow } = require("ow")

module.exports = class Audic {
	constructor(src) {
		ow(src, ow.string)

		this._src = src
		this.playing = true
		this._volume = 1.0
		this._proc = execa("./lib/win32/mplayer-svn-38151-x86_64/mplayer.exe", ["-slave", src])
		this._proc.stdout.on("data", (val) => {
			const data = val.toString()

			const matched = data.match(/A:  (?<currentTime>.+) \(.+\) of (?<duration>.+) \(.+\)  .+%/)

			if (matched && matched.groups) {
				const { currentTime, duration } = matched.groups
				this.currentTime = Number(currentTime)
				this.duration = Number(duration)
			}
		})
	}

	get src() {
		return this._src
	}

	set src(value) {
		ow(value, ow.string)

		this._proc.stdin.write("stop\n")
		this._proc.stdin.write(`loadfile "${value}"\n`)
		this._src = value
	}

	play() {
		if (!this.playing) {
			this._proc.stdin.write("pause\n")
			this.playing = true
		}
	}

	pause() {
		if (this.playing) {
			this._proc.stdin.write("pause\n")
			this.playing = false
		}
	}

	get volume() {
		return this._volume
	}

	set volume(value) {
		ow(value, ow.number.inRange(0, 1))

		this._proc.stdin.write(`volume ${value} 1\n`)
		this._volume = value
	}
}