package com.camerakit.amazonivs.sample

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.RelativeLayout
import android.widget.TextView
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.ListAdapter
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.snap.camerakit.lenses.LensesComponent

internal class LensesAdapter(
    private val onItemClicked: (LensesComponent.Lens) -> Unit
) : ListAdapter<LensesComponent.Lens, LensesAdapter.ViewHolder>(DIFF_CALLBACK) {

    private var selectedPosition = -1

    fun select(lens: LensesComponent.Lens) {
        val position = currentList.indexOf(lens)
        if (position != -1) {
            val previousSelectedPosition = selectedPosition
            selectedPosition = position
            notifyItemChanged(previousSelectedPosition)
            notifyItemChanged(position)
        }
    }

    fun deselect() {
        val previousSelectedPosition = selectedPosition
        selectedPosition = -1
        notifyItemChanged(previousSelectedPosition)
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.lens_item, parent, false))
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bindTo(getItem(position))
        holder.itemView.isSelected = selectedPosition == position
    }

    inner class ViewHolder(view: View) : RecyclerView.ViewHolder(view), View.OnClickListener {

        init {
            view.setOnClickListener(this)
        }

        private val lensNameView: TextView = view.findViewById(R.id.text_view_lens_name)
        private val lensIconView: ImageView = view.findViewById(R.id.image_view_lens_icon)
        private val lensItemRoot: RelativeLayout = view.findViewById(R.id.relative_layout_lens_item_root)

        fun bindTo(lens: LensesComponent.Lens) {
            lensNameView.text = lens.name
            Glide.with(itemView)
                .load(lens.icons.find { it is LensesComponent.Lens.Media.Image.Webp }?.uri)
                .into(lensIconView)
            if (selectedPosition == layoutPosition) {
                lensItemRoot.setBackgroundResource(R.drawable.selected_lens_background)
            } else {
                lensItemRoot.setBackgroundResource(R.drawable.lens_item_background)
            }
        }

        override fun onClick(v: View) {
            val position = adapterPosition
            if (position != RecyclerView.NO_POSITION) {
                onItemClicked(getItem(position))
            }
        }
    }

    companion object {

        val DIFF_CALLBACK = object : DiffUtil.ItemCallback<LensesComponent.Lens>() {

            override fun areItemsTheSame(
                oldItem: LensesComponent.Lens,
                newItem: LensesComponent.Lens
            ) = oldItem.id == newItem.id

            override fun areContentsTheSame(
                oldItem: LensesComponent.Lens,
                newItem: LensesComponent.Lens
            ) = oldItem == newItem
        }
    }
}