import androidx.databinding.Observable
import androidx.databinding.PropertyChangeRegistry
import androidx.lifecycle.ViewModel
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import kotlin.coroutines.CoroutineContext

open class ObservableViewModel : ViewModel(), CoroutineScope, Observable {

    private val callbacks = PropertyChangeRegistry()

    private val job = Job()

    override val coroutineContext: CoroutineContext
        get() = Dispatchers.Default + job

    override fun onCleared() {
        super.onCleared()
        job.cancel()
    }


    override fun removeOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
        callbacks.remove(callback)
    }

    override fun addOnPropertyChangedCallback(callback: Observable.OnPropertyChangedCallback?) {
        callbacks.add(callback)
    }

    fun notifyPropertyChanged(fieldId: Int) {
        callbacks.notifyCallbacks(this, fieldId, null)
    }
}