LibreTube/app/src/main/java/com/github/libretube/Subscriptions.kt

package com.github.libretube

import android.content.Context
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 android.widget.*
import androidx.lifecycle.lifecycleScope
import androidx.preference.PreferenceManager
import androidx.recyclerview.widget.GridLayoutManager
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.github.libretube.adapters.SubscriptionAdapter
import com.github.libretube.adapters.SubscriptionChannelAdapter
import retrofit2.HttpException
import java.io.IOException

class Subscriptions : Fragment() {
    val TAG = "SubFragment"
    lateinit var token: String
    var isLoaded = false
    private var subscriptionAdapter: SubscriptionAdapter? =null
    private var refreshLayout: SwipeRefreshLayout? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        arguments?.let {
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_subscriptions, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        val sharedPref = context?.getSharedPreferences("token", Context.MODE_PRIVATE)
        token = sharedPref?.getString("token","")!!
        refreshLayout = view.findViewById(R.id.sub_refresh)
        if(token!=""){
            view.findViewById<RelativeLayout>(R.id.loginOrRegister).visibility=View.GONE
            refreshLayout?.isEnabled = true

            var progressBar = view.findViewById<ProgressBar>(R.id.sub_progress)
            progressBar.visibility=View.VISIBLE

            var channelRecView = view.findViewById<RecyclerView>(R.id.sub_channels)
            channelRecView?.layoutManager = LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
            fetchChannels(channelRecView)

            var feedRecView = view.findViewById<RecyclerView>(R.id.sub_feed)
            val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(requireContext())
            val grid = sharedPreferences.getString("grid", resources.getInteger(R.integer.grid_items).toString())!!
            feedRecView.layoutManager = GridLayoutManager(view.context, grid.toInt())
            fetchFeed(feedRecView, progressBar, view)

            refreshLayout?.setOnRefreshListener {
                fetchChannels(channelRecView)
                fetchFeed(feedRecView, progressBar, view)
            }

            val scrollView = view.findViewById<ScrollView>(R.id.scrollview_sub)
            scrollView.viewTreeObserver
                .addOnScrollChangedListener {
                    if (scrollView.getChildAt(0).bottom
                        == (scrollView.height + scrollView.scrollY)) {
                        //scroll view is at bottom
                        if(isLoaded){
                            refreshLayout?.isRefreshing = true
                            subscriptionAdapter?.updateItems()
                            refreshLayout?.isRefreshing = false
                        }

                    }
                }
        } else {
            refreshLayout?.isEnabled = false
        }
    }

    private fun fetchFeed(feedRecView: RecyclerView, progressBar: ProgressBar, view: View) {
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    RetrofitInstance.api.getFeed(token)
                }catch(e: IOException) {
                    Log.e(TAG,e.toString())
                    Log.e(TAG, "IOException, you might not have internet connection")
                    return@launchWhenCreated
                } catch (e: HttpException) {
                    Log.e(TAG, "HttpException, unexpected response")
                    return@launchWhenCreated
                } finally {
                    refreshLayout?.isRefreshing = false
                }
                if (response.isNotEmpty()){
                    subscriptionAdapter = SubscriptionAdapter(response)
                    feedRecView?.adapter= subscriptionAdapter
                    subscriptionAdapter?.updateItems()
                }else{
                    runOnUiThread {
                        with(view.findViewById<ImageView>(R.id.boogh)){
                            visibility=View.VISIBLE
                            setImageResource(R.drawable.ic_list)
                        }
                        with(view.findViewById<TextView>(R.id.textLike)){
                            visibility=View.VISIBLE
                            text = getString(R.string.emptyList)
                        }
                        view.findViewById<RelativeLayout>(R.id.loginOrRegister).visibility=View.VISIBLE
                    }
                }
                progressBar.visibility=View.GONE
                isLoaded=true
            }
        }
        run()
    }

    private fun fetchChannels(channelRecView: RecyclerView) {
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    RetrofitInstance.api.subscriptions(token)
                }catch(e: IOException) {
                    Log.e(TAG,e.toString())
                    Log.e(TAG, "IOException, you might not have internet connection")
                    return@launchWhenCreated
                } catch (e: HttpException) {
                    Log.e(TAG, "HttpException, unexpected response")
                    return@launchWhenCreated
                } finally {
                    refreshLayout?.isRefreshing = false
                }
                if (response.isNotEmpty()){
                    channelRecView?.adapter=SubscriptionChannelAdapter(response.toMutableList())
                }else{
                    Toast.makeText(context,R.string.subscribeIsEmpty, Toast.LENGTH_SHORT).show()
                }
            }
        }
        run()
    }
    override fun onDestroy() {
        Log.e(TAG,"Destroyed")
        super.onDestroy()
        subscriptionAdapter = null
        view?.findViewById<RecyclerView>(R.id.sub_feed)?.adapter=null
    }
    private fun Fragment?.runOnUiThread(action: () -> Unit) {
        this ?: return
        if (!isAdded) return // Fragment not attached to an Activity
        activity?.runOnUiThread(action)
    }

}