import android.content.Context;
import android.graphics.Rect;
import android.support.annotation.DimenRes;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;

import com.showroomtechnologies.showroom.R;

public class SpacingItemDecoration extends RecyclerView.ItemDecoration {

    private final int paddingLeft;
    private final int paddingTop;
    private final int paddingRight;
    private final int paddingBottom;

    public SpacingItemDecoration(Context context) {
        this(context, R.dimen.normal);
    }

    public SpacingItemDecoration(Context context, @DimenRes int padding) {
        this(context, padding, padding, padding, padding);
    }

    public SpacingItemDecoration(Context context,
                                 @DimenRes int paddingLeft,
                                 @DimenRes int paddingTop,
                                 @DimenRes int paddingRight,
                                 @DimenRes int paddingBottom) {
        this.paddingLeft = (int) context.getResources().getDimension(paddingLeft);
        this.paddingTop = (int) context.getResources().getDimension(paddingTop);
        this.paddingRight = (int) context.getResources().getDimension(paddingRight);
        this.paddingBottom = (int) context.getResources().getDimension(paddingBottom);
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        if (!(parent.getLayoutManager() instanceof LinearLayoutManager)) throw new IllegalArgumentException("You must use LinearLayoutManager");
        outRect.left = paddingLeft / 2;
        outRect.right = paddingRight / 2;
        outRect.top = paddingTop / 2;
        outRect.bottom = paddingBottom / 2;
    }
}