package xyz.adjutor.aniki.topmanga

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 com.google.android.material.snackbar.Snackbar
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 TopMangaPage : Fragment() {

    var sharedPreferences: SharedPreferences? = null
    val gson = GsonBuilder()
            .setLenient()
            .create()
    var base_url = "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_manga_page, container, false)

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

        val mangaList: List<TopManga>? = getDataFromCache()
        if(mangaList != null ){
            showList(view, mangaList)
        } else {
            makeApiCall(view, base_url)
        }

        return view
    }

    private fun getDataFromCache(): List<TopManga>? {
        //the value of the mangaList json, if nothing is found, return null
        val jsonManga: String? = sharedPreferences?.getString("jsonMangaList", null)

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

    }

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

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

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

        val service = retrofit.create(TopMangaApi::class.java)
        val call = service.getTopMangaData()

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

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

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

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

        })
    }

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

        sharedPreferences
                ?.edit()
                ?.putString("jsonMangaList", jsonString)
                ?.apply()
    }

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

}