Collections Fragment.kt

Collections Fragment.kt

package ng.chaka.android.home.tabs.explore.ui

import android.os.Bundle
import android.os.Handler
import android.view.View
import android.widget.Toast
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProvider
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import javax.inject.Inject
import kotlinx.android.synthetic.main.collections.*
import ng.chaka.android.R
import ng.chaka.android.core.android.BaseFragment
import ng.chaka.android.core.android.Resource
import ng.chaka.android.core.android.Status
import ng.chaka.android.core.android.widget.EndlessRecyclerViewScrollListener
import ng.chaka.android.core.hide
import ng.chaka.android.core.show
import ng.chaka.android.home.tabs.explore.db.Collections

class CollectionsFragment : BaseFragment(R.layout.collections) {
    @Inject
    lateinit var factory: ViewModelProvider.Factory

    private val viewModel by lazy {
        ViewModelProvider(this, factory)[CollectionsViewModel::class.java]
    }

    private lateinit var adapter: CollectionsAdapter

    private var isLoading = false
    private val limit = 10
    lateinit var layoutManager: LinearLayoutManager


    private val exploreViewModel by lazy {
        ViewModelProvider(activity!!, factory)[ExploreViewModel::class.java]
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) =
        super.onViewCreated(view, savedInstanceState).also {
            setupAdapter()
            addObservers()

            swipeRefresh.setOnRefreshListener {
                viewModel.nextPage = 0
                viewModel.refreshCollections(true)
            }
        }

    private fun setupAdapter() {
        adapter = CollectionsAdapter(requireContext())
        recyclerView.adapter = adapter
        viewModel.refreshCollections()
    }

    private fun addObservers() {
        recyclerView.adapter = adapter
        val endlessRecyclerViewScrollListener = object: EndlessRecyclerViewScrollListener(recyclerView.layoutManager as LinearLayoutManager) {
            override fun onLoadMore(page: Int, totalItemsCount: Int, view: RecyclerView?) {
                viewModel.nextPage = page
                viewModel.refreshCollections()
////                val visibleItems = view.childCount
//                val pastVisibleItem = view.if (view != null) {
//                    if (view.childCount < 10) {
//                        viewModel.nextPage = page
//                        viewModel.refreshCollections()
////                        adapter.notifyDataSetChanged()
//                    }
//                }
            }

        }

        recyclerView.addOnScrollListener(endlessRecyclerViewScrollListener)

        viewModel.collectionsLiveData.observe(viewLifecycleOwner, Observer { resource ->
            swipeRefresh.isRefreshing = when (resource.status) {
                Status.SUCCESS -> {
                    showCollections(resource)
                    false
                }
                Status.LOADING -> {
                    true
                }
                Status.ERROR -> {
                    Toast.makeText(
                        requireContext(),
                        resource.message ?: getString(R.string.generic_error),
                        Toast.LENGTH_SHORT
                    ).show()
                    false
                }
            }
        })
    }

    private fun showCollections(resource: Resource<List<Collections>>) {
        val data = resource.data ?: return
//        adapter.collectionsList = data

//        adapter.notifyDataSetChanged()
        if (data.isEmpty()) {
            noDataTextView.show()
            recyclerView.hide()
        } else {
            noDataTextView.hide()
            recyclerView.show()
            adapter.collectionsList = data
        }
    }


    fun <T, R> List<T>.minus(elements: List<T>, selector: (T) -> R?)
            = filter{ t -> elements.none{ selector(it) == selector(t) } }

    companion object {
        fun newInstance(): CollectionsFragment {
            return CollectionsFragment()
        }
    }
}