package jp.juggler.subwaytooter

import android.os.Handler
import android.os.SystemClock
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.ListUpdateCallback
import androidx.recyclerview.widget.RecyclerView
import android.view.ViewGroup
import jp.juggler.subwaytooter.api.entity.TimelineItem
import jp.juggler.util.LogCategory

internal class ItemListAdapter(
	private val activity : ActMain,
	private val column : Column,
	internal val columnVh : ColumnViewHolder,
	private val bSimpleList : Boolean
) : androidx.recyclerview.widget.RecyclerView.Adapter<androidx.recyclerview.widget.RecyclerView.ViewHolder>() {
	
	companion object {
		private val log = LogCategory("ItemListAdapter")
	}
	
	private inner class DiffCallback(
		val oldList : List<TimelineItem>,
		val newList : List<TimelineItem>,
		val biasListIndex : Int
	) : DiffUtil.Callback() {
		
		override fun getOldListSize() : Int {
			return oldList.size - biasListIndex
		}
		
		override fun getNewListSize() : Int {
			return newList.size - biasListIndex
		}
		
		override fun areItemsTheSame(oldAdapterIndex : Int, newAdapterIndex : Int) : Boolean {
			val oldListIndex = oldAdapterIndex + biasListIndex
			val newListIndex = newAdapterIndex + biasListIndex
			
			// header?
			if(oldListIndex < 0 || newListIndex < 0) return oldListIndex == newListIndex
			
			// compare object address
			return oldList[oldListIndex] === newList[newListIndex]
		}
		
		override fun areContentsTheSame(oldAdapterIndex : Int, newAdapterIndex : Int) : Boolean {
			val oldListIndex = oldAdapterIndex + biasListIndex
			val newListIndex = newAdapterIndex + biasListIndex
			
			// headerは毎回更新する
			return ! (oldListIndex < 0 || newListIndex < 0)
		}
	}
	
	private var list : ArrayList<TimelineItem>
	private val handler : Handler
	
	init {
		this.list = ArrayList()
		this.handler = activity.handler
		setHasStableIds(true)
	}
	
	override fun getItemCount() : Int {
		return column.toAdapterIndex(column.list_data.size)
	}
	
	override fun getItemId(position : Int) : Long {
		return try {
			list[column.toListIndex(position)].listViewItemId
		} catch(ignored : Throwable) {
			0L
		}
	}
	
	override fun getItemViewType(position : Int) : Int {
		val headerType = column.headerType
		if(headerType == null || position > 0) return 0
		return headerType.viewType
	}
	
	override fun onCreateViewHolder(parent : ViewGroup, viewType : Int) : androidx.recyclerview.widget.RecyclerView.ViewHolder {
		when(viewType) {
			0 -> {
				val holder = ItemViewHolder(activity)
				holder.viewRoot.tag = holder
				return ViewHolderItem(holder)
			}
			
			Column.HeaderType.Profile.viewType -> {
				val viewRoot =
					activity.layoutInflater.inflate(R.layout.lv_header_profile, parent, false)
				val holder = ViewHolderHeaderProfile(activity, viewRoot)
				viewRoot.tag = holder
				return holder
			}
			
			Column.HeaderType.Search.viewType -> {
				val viewRoot =
					activity.layoutInflater.inflate(R.layout.lv_header_search_desc, parent, false)
				val holder = ViewHolderHeaderSearch(activity, viewRoot)
				viewRoot.tag = holder
				return holder
			}
			
			Column.HeaderType.Instance.viewType -> {
				val viewRoot =
					activity.layoutInflater.inflate(R.layout.lv_header_instance, parent, false)
				val holder = ViewHolderHeaderInstance(activity, viewRoot)
				viewRoot.tag = holder
				return holder
			}
			
			Column.HeaderType.Filter.viewType ->{
				val viewRoot =
					activity.layoutInflater.inflate(R.layout.lv_header_filter, parent, false)
				val holder = ViewHolderHeaderFilter(activity, viewRoot)
				viewRoot.tag = holder
				return holder
			}
			
			else -> throw RuntimeException("unknown viewType: $viewType")
		}
	}
	
	fun findHeaderViewHolder(listView : androidx.recyclerview.widget.RecyclerView) : ViewHolderHeaderBase? {
		return when(column.headerType) {
			null -> null
			else -> listView.findViewHolderForAdapterPosition(0) as? ViewHolderHeaderBase
		}
	}
	
	override fun onBindViewHolder(holder : androidx.recyclerview.widget.RecyclerView.ViewHolder, adapterIndex : Int) {
		if(holder is ViewHolderItem) {
			val listIndex = column.toListIndex(adapterIndex)
			holder.ivh.bind(this, column, bSimpleList, list[listIndex])
		} else if(holder is ViewHolderHeaderBase) {
			holder.bindData(column)
		}
	}
	
	override fun onViewRecycled(holder : androidx.recyclerview.widget.RecyclerView.ViewHolder) {
		if(holder is ViewHolderItem) {
			holder.ivh.onViewRecycled()
		} else if(holder is ViewHolderHeaderBase) {
			holder.onViewRecycled()
		}
	}
	
	
	fun notifyChange(
		reason : String,
		changeList : List<AdapterChange>? = null,
		reset : Boolean = false
	) {
		
		val time_start = SystemClock.elapsedRealtime()
		
		// カラムから最新データをコピーする
		val new_list = ArrayList<TimelineItem>()
		new_list.ensureCapacity(column.list_data.size)
		new_list.addAll(column.list_data)
		
		when {
			// 変更リストが指定された場合はヘッダ部分と変更部分を通知する
			changeList != null -> {
				
				log.d("notifyChange: changeList=${changeList.size},reason=$reason")

				this.list = new_list

				// ヘッダは毎回更新する
				// (ヘッダだけ更新するためにカラのchangeListが渡される)
				if(column.headerType != null){
					notifyItemRangeChanged(0, 1)
				}

				// 変更リストを順番に通知する
				for(c in changeList) {
					val adapterIndex = column.toAdapterIndex(c.listIndex)
					log.d("notifyChange: ChangeType=${c.type} offset=$adapterIndex,count=${c.count}")
					when(c.type) {
						AdapterChangeType.RangeInsert -> notifyItemRangeInserted(adapterIndex, c.count)
						AdapterChangeType.RangeRemove -> notifyItemRangeRemoved(adapterIndex, c.count)
						AdapterChangeType.RangeChange -> notifyItemRangeChanged(adapterIndex, c.count)
					}
				}
			}

			reset -> {
				log.d("notifyChange: DataSetChanged! reason=$reason")
				this.list = new_list
				notifyDataSetChanged()
			}

			else -> {

				val diffResult = DiffUtil.calculateDiff(
					DiffCallback(
						oldList = this.list, // 比較対象の古いデータ
						newList = new_list,
						biasListIndex = column.toListIndex(0)
					),
					false // ログを見た感じ、移動なんてなかった
				)
				val time = SystemClock.elapsedRealtime() - time_start
				log.d("notifyChange: size=${new_list.size},time=${time}ms,reason=$reason")
				
				this.list = new_list
				diffResult.dispatchUpdatesTo(object : ListUpdateCallback {
					
					override fun onInserted(position : Int, count : Int) {
						log.d("notifyChange: notifyItemRangeInserted offset=$position,count=$count")
						notifyItemRangeInserted(position, count)
					}
					
					override fun onRemoved(position : Int, count : Int) {
						log.d("notifyChange: notifyItemRangeRemoved offset=$position,count=$count")
						notifyItemRangeRemoved(position, count)
					}
					
					override fun onChanged(position : Int, count : Int, payload : Any?) {
						log.d("notifyChange: notifyItemRangeChanged offset=$position,count=$count")
						notifyItemRangeChanged(position, count, payload)
					}
					
					override fun onMoved(fromPosition : Int, toPosition : Int) {
						log.d("notifyChange: notifyItemMoved from=$fromPosition,to=$toPosition")
						notifyItemMoved(fromPosition, toPosition)
					}
					
				})
			}
		
		}
		
		// diffを取る部分をワーカースレッドで実行したいが、直後にスクロール位置の処理があるので差支えがある…
	}
	
}