import io.reactivex.Observable
import io.reactivex.rxkotlin.Observables
import io.reactivex.schedulers.Schedulers
import io.reactivex.subjects.PublishSubject

val BAD_SESSION_ID = "BAD_SESSION_ID"
val GOOD_SESSION_ID = "GOOD_SESSION_ID"

fun main(args: Array<String>) {
    val responseSubject = PublishSubject.create<ErrorCode>()

    responseSubject
            .subscribeOn(Schedulers.trampoline())
            .subscribe({ value ->
                println("value: $value")
            }, { error ->
                println(error.message)
            }, {
                println("onComplete")
            })

    val fileList = listOf("file1", "file2", "file3", "file4")
    val filesObservables = Observable.fromIterable(fileList)
            .subscribeOn(Schedulers.trampoline())
            .flatMap { prepareFile(it) }
            .toList()
            .toObservable()
            .share()

    val requestObservable = Observable.just(Request("test", 0))

    val responseObservable = Observables.zip(filesObservables, requestObservable, { a, b -> Pair(a, b) })
            .flatMap { sendRequest(it.first, it.second, BAD_SESSION_ID) }
            .share()

    responseObservable
            .filter { it == ErrorCode.OK }
            .subscribe(responseSubject)

    val sessionIdObservable = responseObservable
            .filter { it == ErrorCode.BAD_SESSION_ID }
            .flatMap { reLogin() }

    Observables.zip(sessionIdObservable, filesObservables, requestObservable, { a, b, c -> Triple(a, b, c) })
            .flatMap { sendRequest(it.second, it.third, it.first) }
            .subscribe(responseSubject)
}

fun prepareFile(file: String): Observable<String> {
    println("prepareFiles")
    return Observable.just(file)
}

fun reLogin(): Observable<String> {
    println("reLogin")
    return Observable.just(GOOD_SESSION_ID)
}

fun sendRequest(files: MutableList<String>, request: Request, sessionId: String): Observable<ErrorCode> {
    println("sendRequest")

    if (sessionId == BAD_SESSION_ID) {
        return Observable.just(ErrorCode.BAD_SESSION_ID)
    } else {
        return Observable.just(ErrorCode.OK)
    }
}

data class Request(val param1: String,
                   val param2: Int)

enum class ErrorCode {
    OK,
    BAD_SESSION_ID
}