PixelDroid-App-Android/app/src/main/java/com/h/pixeldroid/fragments/feeds/postFeeds/PostsFeedFragment.kt

package com.h.pixeldroid.fragments.feeds.postFeeds

import android.graphics.Color
import android.graphics.drawable.ColorDrawable
import android.graphics.drawable.Drawable
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.*
import androidx.lifecycle.LiveData
import androidx.lifecycle.Observer
import androidx.paging.PagedList
import androidx.recyclerview.widget.RecyclerView
import androidx.viewpager2.widget.ViewPager2
import at.connyduck.sparkbutton.SparkButton
import com.bumptech.glide.Glide
import com.bumptech.glide.ListPreloader
import com.bumptech.glide.RequestBuilder
import com.bumptech.glide.integration.recyclerview.RecyclerViewPreloader
import com.bumptech.glide.util.ViewPreloadSizeProvider
import com.h.pixeldroid.R
import com.h.pixeldroid.fragments.feeds.FeedFragment
import com.h.pixeldroid.fragments.feeds.FeedsRecyclerViewAdapter
import com.h.pixeldroid.objects.Status

abstract class PostsFeedFragment : FeedFragment() {

    lateinit var picRequest: RequestBuilder<Drawable>
    lateinit var domain : String
    protected lateinit var adapter : FeedsRecyclerViewAdapter<Status, PostViewHolder>
    lateinit var factory: FeedDataSourceFactory<String, Status>


    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = super.onCreateView(inflater, container, savedInstanceState)

        domain = user?.instance_uri.orEmpty()
        //RequestBuilder that is re-used for every image
        picRequest = Glide.with(this)
            .asDrawable().fitCenter()
            .placeholder(ColorDrawable(Color.GRAY))

        adapter = PostsFeedRecyclerViewAdapter()
        list.adapter = adapter

        //Make Glide be aware of the recyclerview and pre-load images
        val sizeProvider: ListPreloader.PreloadSizeProvider<Status> = ViewPreloadSizeProvider()
        val preloader: RecyclerViewPreloader<Status> = RecyclerViewPreloader(
            Glide.with(this), adapter as PostsFeedRecyclerViewAdapter, sizeProvider, 4
        )
        list.addOnScrollListener(preloader)

        return view
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        val content = makeContent()
        content.observe(viewLifecycleOwner,
            { c ->
                adapter.submitList(c)
                //after a refresh is done we need to stop the pull to refresh spinner
                swipeRefreshLayout.isRefreshing = false
            })

        swipeRefreshLayout.setOnRefreshListener {
            showError(show = false)

            //by invalidating data, loadInitial will be called again
            factory.liveData.value!!.invalidate()
        }
    }

    internal abstract fun makeContent(): LiveData<PagedList<Status>>

    /**
     * [RecyclerView.Adapter] that can display a list of Statuses
     */
    inner class PostsFeedRecyclerViewAdapter
        : FeedsRecyclerViewAdapter<Status, PostViewHolder>(),
        ListPreloader.PreloadModelProvider<Status> {
        private val api = pixelfedAPI
        private val credential = "Bearer $accessToken"
        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PostViewHolder {
            val view = LayoutInflater.from(parent.context)
                .inflate(R.layout.post_fragment, parent, false)
            context = view.context
            return PostViewHolder(
                view,
                context
            )
        }

        /**
         * Binds the different elements of the Post Model to the view holder
         */
        override fun onBindViewHolder(holder: PostViewHolder, position: Int) {
            val post = getItem(position) ?: return
            val metrics = context.resources.displayMetrics
            //Limit the height of the different images
            holder.postPic.maxHeight = metrics.heightPixels * 3/4

            //Setup the post layout
            post.setupPost(holder.postView, picRequest, this@PostsFeedFragment, domain, false)

            post.activateButtons(holder, api, credential)
        }

        override fun getPreloadItems(position: Int): MutableList<Status> {
            val status = getItem(position) ?: return mutableListOf()
            return mutableListOf(status)
        }

        override fun getPreloadRequestBuilder(item: Status): RequestBuilder<*>? {
            return picRequest.load(item.getPostUrl())
        }
    }
}

/**
 * Represents the posts that will be contained within the feed
 */
class PostViewHolder(val postView: View, val context: android.content.Context) : RecyclerView.ViewHolder(postView) {
    val profilePic  : ImageView = postView.findViewById(R.id.profilePic)
    val postPic     : ImageView = postView.findViewById(R.id.postPicture)
    val username    : TextView  = postView.findViewById(R.id.username)
    val usernameDesc: TextView  = postView.findViewById(R.id.usernameDesc)
    val description : TextView  = postView.findViewById(R.id.description)
    val nlikes      : TextView  = postView.findViewById(R.id.nlikes)
    val nshares     : TextView  = postView.findViewById(R.id.nshares)

    //Spark buttons
    val liker       : SparkButton = postView.findViewById(R.id.liker)
    val reblogger   : SparkButton = postView.findViewById(R.id.reblogger)

    val submitCmnt  : ImageButton = postView.findViewById(R.id.submitComment)
    val commenter   : ImageView = postView.findViewById(R.id.commenter)
    val comment     : EditText = postView.findViewById(R.id.editComment)
    val commentCont : LinearLayout = postView.findViewById(R.id.commentContainer)
    val commentIn   : LinearLayout = postView.findViewById(R.id.commentIn)
    val viewComment : TextView = postView.findViewById(R.id.ViewComments)
    val postDate    : TextView = postView.findViewById(R.id.postDate)
    val postDomain  : TextView = postView.findViewById(R.id.postDomain)
    val sensitiveW  : TextView = postView.findViewById(R.id.sensitiveWarning)
    val postPager  : ViewPager2 = postView.findViewById(R.id.postPager)

    val more        : ImageButton = postView.findViewById(R.id.status_more)
}