package com.example.secondtry

import android.content.Context
import android.graphics.Color
import android.text.TextUtils
import android.view.Gravity
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.textclassifier.TextClassifier.TYPE_EMAIL
import android.widget.Button
import android.widget.LinearLayout
import android.widget.TextView
import androidx.appcompat.app.AlertDialog
import androidx.constraintlayout.widget.ConstraintLayout
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.recyclerview.widget.RecyclerView.ViewHolder
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.async
import org.koin.core.KoinComponent
import org.koin.core.inject
import java.util.*
import kotlin.collections.HashMap
import kotlin.time.ExperimentalTime
import kotlin.time.seconds

class WallpostsListAdapter(
        private val wallposts: List<Wallpost>,
        private val recyclerView: RecyclerView) :

        RecyclerView.Adapter<ViewHolder>(), KoinComponent {

    companion object {
        const val WALLPOST_VIEW = 0
        const val COMMENTS_VIEW = 1
    }

    private val repository by inject<WallpostsRepository>()
    val viewTypeFlags: BooleanArray
    val wallpostsPosMap = HashMap<Int, Int>()
    val commentsWpMap = HashMap<Int, Int>()
    val viewHolders = LinkedList<MyViewHolder>()
    val commentViewHolders = LinkedList<CommentsViewHolder>()

    init {
        val totalCommentsCount = wallposts.sumBy { wp -> wp.comments.size }
        val viewsCount = wallposts.size + totalCommentsCount
        viewTypeFlags = BooleanArray(viewsCount)

        var adapterIdx = 0

        wallposts.forEachIndexed { wpArrIdx, wp ->
            wallpostsPosMap[adapterIdx] = wpArrIdx
            viewTypeFlags[adapterIdx] = true

            wp.comments.forEachIndexed { commArrIdx, _  ->
                var commAdapterIdx = adapterIdx + commArrIdx + 1
                commentsWpMap[commAdapterIdx] = adapterIdx
                viewTypeFlags[commAdapterIdx] = false
            }

            adapterIdx += wp.comments.size + 1
        }
    }

    class MyViewHolder(layout: ConstraintLayout,
                       context: Context) : ViewHolder(layout) {
        val wpContent: TextView = layout.findViewById(R.id.wpContent)
        val wpHeader: TextView = layout.findViewById(R.id.wpHeader)
        val wpLinks: TextView = layout.findViewById(R.id.wpLinks)
        val likeBtn: Button = layout.findViewById(R.id.btnLike)
        val commentBtn: Button = layout.findViewById(R.id.btnComment)
        val shareBtn: Button = layout.findViewById(R.id.btnShare)
        val dialog = AlertDialog.Builder(context)

        init {
            dialog.setTitle("Under construction")
                    .setMessage("Functionality is currently under construction. Try again later.")
                    .setNeutralButton("Go back") { dialog, _ ->
                        dialog.cancel()
                    }
        }
    }

    class CommentsViewHolder(layout: LinearLayout) : ViewHolder(layout) {
        val commentHeader: TextView = layout.findViewById(R.id.commentHeader)
        val commentContent: TextView = layout.findViewById(R.id.commentContent)
        val date: TextView = layout.findViewById(R.id.date)
    }

    override fun getItemCount(): Int {
        return viewTypeFlags.size
    }

    override fun getItemViewType(position: Int): Int {
        return if (viewTypeFlags[position]) {
            WALLPOST_VIEW
        } else {
            COMMENTS_VIEW
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        if (viewType == COMMENTS_VIEW) {
            return commentViewHolders.pop()
        }

        val viewHolder = viewHolders.pop()

        val onLikeClick = { likeBtn: View ->
            val index = recyclerView.getChildLayoutPosition(likeBtn.parent as View)
            val wp = wallposts[index]

            // TODO: check if global scope should be used
            // TODO: check how to avoid writing an unused variable to avoid returning job
            val job = GlobalScope.async {
                val newLiked = if (wp.liked == null) true else !wp.liked

                repository.likeWallpost(wallposts[index].id, newLiked)

                wallposts[index].liked = newLiked
                notifyItemChanged(index)
            }
        }

        val onCommentClick = { _: View ->
            val dialog = viewHolder.dialog.show()
            val neutralBtn = dialog.getButton(AlertDialog.BUTTON_NEUTRAL)
            val layoutParams = LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT)
            layoutParams.gravity = Gravity.CENTER
            neutralBtn.layoutParams = layoutParams
        }

        viewHolder.apply {
            likeBtn.setOnClickListener(onLikeClick)
            commentBtn.setOnClickListener(onCommentClick)
            shareBtn.setOnClickListener(onCommentClick)
        }

        return viewHolder
    }

    @ExperimentalTime
    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        if (holder is MyViewHolder) {
            bindWallpostsViewHolder(holder, position)
        }

        if (holder is CommentsViewHolder) {
            bindCommentsHolder(holder, position)
        }
    }

    private fun bindWallpostsViewHolder(holder: MyViewHolder, position: Int) {
        val wpArrIdx = wallpostsPosMap[position]!!
        val wp = wallposts[wpArrIdx]
        val headerText = "${wp.username} on ${wp.datePosted}"
        val linksText = "Show previous comments (${wp.comments.size} of 5) ---- Reply ----"

        holder.apply {
            toggleLikeBtn(likeBtn, wp.liked)

            wpContent.text = wp.content
            wpHeader.text = headerText
            wpLinks.text = linksText
        }
    }

    @ExperimentalTime
    private fun bindCommentsHolder(holder: CommentsViewHolder, position: Int) {

        val relatedWpAdapterIdx = commentsWpMap[position]!!
        val wpArrIdx = wallpostsPosMap[relatedWpAdapterIdx]!!
        val commArrIdx = position - relatedWpAdapterIdx - 1

        val comment = wallposts[wpArrIdx].comments[commArrIdx]
        val headerText = "${comment.username} on ${comment.datePosted}"

        val now = Date()
        val timeDiff = now.time - comment.datePosted.time
        val isRecent = timeDiff.seconds.inSeconds < 100L

        holder.date.text = if (isRecent) "Just now" else "2h"
        holder.commentHeader.text = headerText
        holder.commentContent.text = comment.content
    }

    private fun toggleLikeBtn(likeBtn: Button, liked: Boolean) {
        val likeImg = if (liked) R.drawable.favourite else R.drawable.like
        val textColor = if (liked) "#065fd4" else "#808080"

        likeBtn.setCompoundDrawablesWithIntrinsicBounds(likeImg, 0, 0, 0)
        likeBtn.setTextColor(Color.parseColor(textColor))
    }
}