package com.example.myapplication.ui.main

import android.os.Bundle
import android.util.Log
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.lifecycle.*
import com.example.myapplication.R
import kotlinx.coroutines.Job
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.flow.*
import kotlinx.coroutines.launch


class MainViewModel: ViewModel() {
    private var counter = 0

    private val _events = MutableSharedFlow<String>(replay = 1, extraBufferCapacity = 500)
    val events = _events.asSharedFlow()

     fun createEvent(eventName: String) {
        viewModelScope.launch {
            if (eventName.equals("ON_DESTROY")) {
                for (i in 0..8) {
                    val eventValue = eventName + counter++
                    Log.d("TESTING", "View model - Emitting event: $eventValue")
                    _events.emit(eventValue)
                }
            } else {
                val eventValue = eventName + counter++
                Log.d("TESTING", "View model - Emitting event: $eventValue")
                _events.emit(eventValue)
            }
        }
    }
}

class MainFragment : Fragment() {

    companion object {
        fun newInstance() = MainFragment()
    }

    private lateinit var viewModel: MainViewModel

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        return inflater.inflate(R.layout.main_fragment, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        viewModel = ViewModelProvider(this).get(MainViewModel::class.java)

        viewLifecycleOwner.lifecycle.addObserver(LifecycleEventObserver { _: LifecycleOwner, event: Lifecycle.Event ->
            viewModel.createEvent(event.name)
        })

        viewLifecycleOwner.lifecycleScope.launch {
            viewModel.events
                    .onStart {
                        val state = lifecycle.currentState
                        Log.d("TESTING", "Flow observer1 - Starting in state $state")
                    }
                    .onCompletion {
                        val state = lifecycle.currentState
                        Log.d("TESTING", "Flow observer1 - Completing in state $state")
                    }
                    .catch {
                        val state = lifecycle.currentState
                        Log.d("TESTING", "Flow observer1 - caught $it")
                    }
                    .collect {
                        val state = lifecycle.currentState
                        Log.d("TESTING", "Flow observer1 - Got value $it in state $state")
                    }
        }
    }
}