package com.wpc.library.recyclerviewhelper;

import android.graphics.Canvas;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;
import androidx.recyclerview.widget.ItemTouchHelper;

/**
 * ItemDragHelperCallback
 * Created by YoKeyword on 15/12/29.
 */
public class ItemDragHelperCallback extends ItemTouchHelper.Callback {

    private int noMovePosition;

    public ItemDragHelperCallback(int noMovePosition) {
        this.noMovePosition = noMovePosition;
    }

    @Override
    public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        int fromPosition = viewHolder.getAdapterPosition();
        if (fromPosition < noMovePosition)
            return 0;
        int dragFlags;
        RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
        if (manager instanceof GridLayoutManager || manager instanceof StaggeredGridLayoutManager) {
            dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
        } else {
            dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
        }
        // 如果想支持滑动(删除)操作, swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END
        int swipeFlags = 0;
        return makeMovementFlags(dragFlags, swipeFlags);
    }

    @Override
    public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
        // 不同Type之间不可移动
        if (viewHolder.getItemViewType() != target.getItemViewType()) {
            return false;
        }

        if (recyclerView.getAdapter() instanceof OnItemMoveListener && direction != 0) {
            OnItemMoveListener listener = ((OnItemMoveListener) recyclerView.getAdapter());
            listener.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition(), direction);
            direction = 0;
        }
        return true;
    }

    int direction = 0;//1、上拉；2、下滑；3、左滑；4、右滑
    float itemWidth = 0;
    float itemHeight = 0;

    @Override
    public void onChildDrawOver(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
        super.onChildDrawOver(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
        int fromPosition = viewHolder.getAdapterPosition();
        if (itemWidth == 0) {
            //获取单个Item宽度
            itemWidth = recyclerView.getChildAt(fromPosition).getMeasuredWidth() / 2;
        }

        if (itemHeight == 0) {
            //获取单个Item高度
            itemHeight = recyclerView.getChildAt(fromPosition).getMeasuredHeight() / 2;
        }

//        Log.e("mResult", "scrollX:" + itemWidth + "---scrollY:" + itemHeight);
        if (dX < 0 && Math.abs(dX) >= itemWidth) {
            direction = 3;
        } else if (dX > 0 && Math.abs(dX) >= itemWidth) {
            direction = 4;
        } else if (dY < 0 && Math.abs(dY) >= itemHeight) {
            direction = 1;
        } else if (dY > 0 && Math.abs(dY) >= itemHeight) {
            direction = 2;
        } else {
            direction = 0;
        }

        if (Math.abs(dX) >= itemWidth || Math.abs(dY) >= itemHeight) {
            onMove(recyclerView, viewHolder, viewHolder);
        }

    }

    @Override
    public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {

    }

    @Override
    public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
        // 不在闲置状态
        if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
            if (viewHolder instanceof OnDragVHListener) {
                OnDragVHListener itemViewHolder = (OnDragVHListener) viewHolder;
                itemViewHolder.onItemSelected();
            }
        }
        super.onSelectedChanged(viewHolder, actionState);
    }

    @Override
    public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
        if (viewHolder instanceof OnDragVHListener) {
            OnDragVHListener itemViewHolder = (OnDragVHListener) viewHolder;
            itemViewHolder.onItemFinish();
        }
        super.clearView(recyclerView, viewHolder);
    }

    @Override
    public boolean isLongPressDragEnabled() {
        // 不支持长按拖拽功能 手动控制
        return false;
    }

    @Override
    public boolean isItemViewSwipeEnabled() {
        // 不支持滑动功能
        return false;
    }
}