package xyz.adjutor.aniki.anime.topanime

import android.content.Context
import android.content.SharedPreferences
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import androidx.fragment.app.Fragment
import androidx.navigation.fragment.findNavController
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
import com.google.android.material.snackbar.Snackbar
import com.google.gson.Gson
import com.google.gson.GsonBuilder
import com.google.gson.reflect.TypeToken
import retrofit2.Call
import retrofit2.Callback
import retrofit2.Response
import retrofit2.Retrofit
import retrofit2.converter.gson.GsonConverterFactory
import xyz.adjutor.aniki.R
import java.lang.reflect.Type

class TopAnimePage : Fragment() {

    private lateinit var sharedPreferences: SharedPreferences
    val gson: Gson = GsonBuilder()
        .setLenient()
        .create()
    var baseUrl = "https://api.jikan.moe/" //the api's base url

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

        sharedPreferences = view.context.getSharedPreferences("sp_anime", Context.MODE_PRIVATE)

        val animeList: List<TopAnime>? = getDataFromCache()
        if (animeList != null) {
            showList(view, animeList)
        } else {
            makeApiCall(view, baseUrl)
        }

        return view
    }

    private fun getDataFromCache(): List<TopAnime>? {
        //the value of the animeList json, if nothing is found, return null
        val jsonAnime: String? = sharedPreferences.getString("jsonAnimeList", null)

        //if it's null, well, return null
        return if (jsonAnime == null) {
            null
        } else { //else deserialize the list and return it
            val listType: Type = object : TypeToken<List<TopAnime>>() {}.type
            gson.fromJson(jsonAnime, listType)
        }
    }

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

        //button to return to the home page
        view.findViewById<Button>(R.id.button_home).setOnClickListener {
            findNavController().navigate(R.id.action_TopAnimePage_to_HomePage)
        }

        fun updateList() {
            makeApiCall(view, baseUrl)
            Snackbar.make(requireView(), "Data refreshed", Snackbar.LENGTH_LONG)
                .setAction("Action", null).show()
        }

        val swipeRefresh: SwipeRefreshLayout = view.findViewById(R.id.swiperefresh)
        swipeRefresh.setOnRefreshListener {
            updateList()
            swipeRefresh.isRefreshing = false
        }

    }

    //display the recyclerview
    fun showList(view: View, animeList: List<TopAnime>) {
        val recyclerView: RecyclerView = view.findViewById(R.id.recycler_view)
        recyclerView.setHasFixedSize(true)
        recyclerView.layoutManager = LinearLayoutManager(view.context)
        recyclerView.adapter = TopAnimeAdapter(animeList)
        (recyclerView.adapter as TopAnimeAdapter).notifyDataSetChanged()
    }

    private fun makeApiCall(view: View, BASE_URL: String) {

        val retrofit = Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create(gson))
            .build()

        val service = retrofit.create(TopAnimeApi::class.java)
        val call = service.getTopAnimeData()

        call.enqueue(object : Callback<TopAnimeResponse> {
            override fun onResponse(
                call: Call<TopAnimeResponse>,
                response: Response<TopAnimeResponse>
            ) {
                if (response.isSuccessful && response.body() != null) { //if the code returned is >= 200 and < 300 AND the the body ain't empty

                    val animeList: List<TopAnime> = response.body()!!
                        .getResults() //getting the "top" field containing our list of TopAnimes
                    saveList(animeList)
                    showList(
                        view,
                        animeList
                    ) //calling the method in charge of displaying on the recyclerview

                } else {
                    showError() //a snackbar
                }
            }

            override fun onFailure(call: Call<TopAnimeResponse>, t: Throwable) {
                showError()
            }

        })
    }

    private fun saveList(animeList: List<TopAnime>) {
        val jsonString: String = gson.toJson(animeList)

        sharedPreferences
            .edit()
            .putString("jsonAnimeList", jsonString)
            .apply()
    }

    private fun showError() {
        Snackbar.make(requireView(), "API ERROR", Snackbar.LENGTH_LONG)
            .setAction("Action", null).show()
    }

}