package test_track

import io.reactivex.Observable
import io.reactivex.functions.BiFunction
import io.reactivex.subjects.BehaviorSubject
import java.util.concurrent.TimeUnit

data class Track(
        val name: String
)

class Player(firstTrack: Track) {

    private val _currentTrack: BehaviorSubject<Track> = BehaviorSubject.createDefault(firstTrack)
    val currentTrack: Observable<Track> get() = _currentTrack

    private val time = Observable.interval(1000, TimeUnit.MILLISECONDS)

    fun startPlaying(tracks: Observable<Track>) {
        Observable.zip(tracks, time, BiFunction { track: Track, _: Long ->
            return@BiFunction track
        })
                .subscribe({ track ->
                    _currentTrack.onNext(track)
                }, {})
    }

    fun changeCurrentTrackName(to: String) {
        _currentTrack.onNext(_currentTrack.value.copy(name = to))
    }

}

fun main(args: Array<String>) {
    val tracks: Observable<Track> = Observable.just(
            Track(name = "Name1"),
            Track(name = "Name2"),
            Track(name = "Name3"),
            Track(name = "Name4")
    )

    val player = Player(Track("Name0"))
    player.currentTrack
            .subscribe {
                println(it)
            }

    player.startPlaying(tracks)
    Thread.sleep(500)
    player.changeCurrentTrackName("Name5")
    Thread.sleep(5000)
}