package com.github.libretube.fragments

import android.annotation.SuppressLint
import android.os.Bundle
import android.util.Log
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.fragment.app.Fragment
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.github.libretube.R
import com.github.libretube.adapters.ChannelAdapter
import com.github.libretube.obj.Subscribe
import com.github.libretube.util.PreferenceHelper
import com.github.libretube.util.RetrofitInstance
import com.github.libretube.util.formatShort
import com.google.android.material.button.MaterialButton
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"
    var nextPage: String? = null
    var channelAdapter: ChannelAdapter? = null
    var isLoading = true
    var isSubscribed: Boolean = false
    private var refreshLayout: SwipeRefreshLayout? = null

    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)
        refreshLayout = view.findViewById(R.id.channel_refresh)

        val refreshChannel = {
            refreshLayout?.isRefreshing = true
            fetchChannel(view)
            val subButton = view.findViewById<MaterialButton>(R.id.channel_subscribe)
            if (PreferenceHelper.getToken(requireContext()) != "") {
                isSubscribed(subButton)
            }
        }
        refreshChannel()
        refreshLayout?.setOnRefreshListener {
            refreshChannel()
        }

        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 && !isLoading) {
                        isLoading = true
                        refreshLayout?.isRefreshing = true
                        fetchNextPage()
                    }
                }
            }
    }

    private fun isSubscribed(button: MaterialButton) {
        @SuppressLint("ResourceAsColor")
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    val token = PreferenceHelper.getToken(requireContext())
                    RetrofitInstance.api.isSubscribed(
                        channel_id!!,
                        token
                    )
                } 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
                }

                runOnUiThread {
                    if (response.subscribed == true) {
                        isSubscribed = true
                        button.text = getString(R.string.unsubscribe)
                    }
                    if (response.subscribed != null) {
                        button.setOnClickListener {
                            if (isSubscribed) {
                                unsubscribe()
                                button.text = getString(R.string.subscribe)
                            } else {
                                subscribe()
                                button.text = getString(R.string.unsubscribe)
                            }
                        }
                    }
                }
            }
        }
        run()
    }

    private fun subscribe() {
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    val token = PreferenceHelper.getToken(requireContext())
                    RetrofitInstance.api.subscribe(
                        token,
                        Subscribe(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$e")
                    return@launchWhenCreated
                }
                isSubscribed = true
            }
        }
        run()
    }

    private fun unsubscribe() {
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    val token = PreferenceHelper.getToken(requireContext())
                    RetrofitInstance.api.unsubscribe(
                        token,
                        Subscribe(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
                }
                isSubscribed = false
            }
        }
        run()
    }

    private fun fetchChannel(view: View) {
        fun run() {
            lifecycleScope.launchWhenCreated {
                val response = try {
                    RetrofitInstance.api.getChannel(channel_id!!)
                } catch (e: IOException) {
                    refreshLayout?.isRefreshing = false
                    println(e)
                    Log.e(TAG, "IOException, you might not have internet connection")
                    return@launchWhenCreated
                } catch (e: HttpException) {
                    refreshLayout?.isRefreshing = false
                    Log.e(TAG, "HttpException, unexpected response")
                    return@launchWhenCreated
                }
                nextPage = response.nextpage
                isLoading = false
                refreshLayout?.isRefreshing = false
                runOnUiThread {
                    view.findViewById<ScrollView>(R.id.channel_scrollView).visibility = View.VISIBLE
                    val channelName = view.findViewById<TextView>(R.id.channel_name)
                    channelName.text = response.name
                    if (response.verified) {
                        channelName.setCompoundDrawablesWithIntrinsicBounds(
                            0,
                            0,
                            R.drawable.ic_verified,
                            0
                        )
                    }
                    view.findViewById<TextView>(R.id.channel_subs).text = resources.getString(
                        R.string.subscribers,
                        response.subscriberCount.formatShort()
                    )
                    val channelDescription = view.findViewById<TextView>(R.id.channel_description)
                    if (response.description?.trim() == "") {
                        channelDescription.visibility = View.GONE
                    } else {
                        channelDescription.text = response.description?.trim()
                    }
                    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(),
                        childFragmentManager
                    )
                    view.findViewById<RecyclerView>(R.id.channel_recView).adapter = channelAdapter
                }
            }
        }
        run()
    }

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

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

    override fun onDestroyView() {
        val scrollView = view?.findViewById<ScrollView>(R.id.channel_scrollView)
        scrollView?.viewTreeObserver?.removeOnScrollChangedListener {
        }
        channelAdapter = null
        view?.findViewById<RecyclerView>(R.id.channel_recView)?.adapter = null
        super.onDestroyView()
    }
}