package com.github.libretube


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.ImageView
import android.widget.ScrollView
import android.widget.TextView
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.github.libretube.adapters.ChannelAdapter
import com.squareup.picasso.Picasso
import retrofit2.HttpException
import java.io.IOException


class ChannelFragment : Fragment() {

    private var channel_id: String? = null
    private val TAG = "ChannelFragment"
    //lateinit var recyclerView: RecyclerView
    var nextPage: String? =null
    lateinit var channelAdapter: ChannelAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        arguments?.let {
            channel_id = it.getString("channel_id")
        }
    }

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


    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        channel_id = channel_id!!.replace("/channel/","")
        view.findViewById<TextView>(R.id.channel_name).text=channel_id
        val recyclerView = view.findViewById<RecyclerView>(R.id.channel_recView)
        recyclerView.layoutManager = LinearLayoutManager(context)

        fetchChannel(view)

    }

    private fun fetchChannel(view: View){
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    RetrofitInstance.api.getChannel(channel_id!!)
                }catch(e: IOException) {
                    println(e)
                    Log.e(TAG, "IOException, you might not have internet connection")
                    return@launchWhenCreated
                } catch (e: HttpException) {
                    Log.e(TAG, "HttpException, unexpected response")
                    return@launchWhenCreated
                }
                nextPage = response.nextpage!!
                runOnUiThread {
                    view.findViewById<TextView>(R.id.channel_name).text=response.name
                    view.findViewById<TextView>(R.id.channel_subs).text=response.subscriberCount.videoViews() + " subscribers"
                    view.findViewById<TextView>(R.id.channel_description).text=response.description
                    val bannerImage = view.findViewById<ImageView>(R.id.channel_banner)
                    val channelImage = view.findViewById<ImageView>(R.id.channel_image)
                    Picasso.get().load(response.bannerUrl).into(bannerImage)
                    Picasso.get().load(response.avatarUrl).into(channelImage)
                    channelAdapter = ChannelAdapter(response.relatedStreams!!.toMutableList())
                    view.findViewById<RecyclerView>(R.id.channel_recView).adapter = channelAdapter
                    val scrollView = view.findViewById<ScrollView>(R.id.channel_scrollView)
                    scrollView.viewTreeObserver
                        .addOnScrollChangedListener {
                            if (scrollView.getChildAt(0).bottom
                                == (scrollView.height + scrollView.scrollY)) {
                                //scroll view is at bottom
                                if(nextPage!=null){
                                    fetchNextPage()
                                }

                            } else {
                                //scroll view is not at bottom
                            }
                        }
                }
            }
        }
        run()
    }
    private fun fetchNextPage(){
        fun run() {

            lifecycleScope.launchWhenCreated {
                val response = try {
                    RetrofitInstance.api.getChannelNextPage(channel_id!!,nextPage!!)
                } catch (e: IOException) {
                    println(e)
                    Log.e(TAG, "IOException, you might not have internet connection")
                    return@launchWhenCreated
                } catch (e: HttpException) {
                    Log.e(TAG, "HttpException, unexpected response,"+e.response())
                    return@launchWhenCreated
                }
                nextPage = response.nextpage
                channelAdapter.updateItems(response.relatedStreams!!)

            }
        }
        run()
    }
    private fun Fragment?.runOnUiThread(action: () -> Unit) {
        this ?: return
        if (!isAdded) return // Fragment not attached to an Activity
        activity?.runOnUiThread(action)
    }

    override fun onDestroyView() {

        view?.findViewById<RecyclerView>(R.id.channel_recView)?.adapter=null
        super.onDestroyView()
    }
}