MainFragment

package com.cinderellaman.live.ui.fragments

import androidx.lifecycle.ViewModelProviders
import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.lifecycle.Observer
import androidx.navigation.findNavController
import androidx.recyclerview.widget.GridLayoutManager
import com.cinderellaman.live.R
import com.cinderellaman.live.ui.activities.MainActivity
import com.cinderellaman.live.ui.adapters.SearchAdapter
import com.cinderellaman.live.ui.viewmodel.MainViewModel
import com.cinderellaman.live.youtubeapi.search.State
import com.cinderellaman.live.youtubeapi.search.response.Item
import kotlinx.android.synthetic.main.main_fragment.*

class MainFragment : Fragment() {
    private lateinit var searchAdapter: SearchAdapter
    private lateinit var viewModel: MainViewModel

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

    override fun onStart() {
        super.onStart()
        (activity as MainActivity).supportActionBar!!.title = "Cartoons"

    }

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

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        viewModel = ViewModelProviders.of(this).get(MainViewModel::class.java)
        initAdapter()
        initSearchState()
   }

    private fun initSearchState() {
        viewModel.getState().observe(this, Observer { state ->
            progress_bar.visibility = if (viewModel.listIsEmpty() && state == State.LOADING) View.VISIBLE else View.GONE
            error_text_view.visibility = if (viewModel.listIsEmpty() && state == State.ERROR) View.VISIBLE else View.GONE

            if (!viewModel.listIsEmpty()){
                searchAdapter.setState(state ?: State.DONE)
            }
        })
    }

    private fun initAdapter() {
        val directions = MainFragmentDirections.actionMainFragmentToPlayerActivity(null)
        searchAdapter = SearchAdapter({viewModel.retry()},{ item: Item?, position: Int ->
            directions.setVideoId(item?.id?.videoId)
            view?.findNavController()?.navigate(directions)
        })
        channels_rv.layoutManager = GridLayoutManager(context,2)
        channels_rv.adapter = searchAdapter
        viewModel.searchList.observe(this, Observer {
            searchAdapter.submitList(it)
        })
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        error_text_view.setOnClickListener { viewModel.retry() }
    }
}