package com.longluo.ebookreader.widget.itemdecoration;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.view.View;

import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

public class DividerItemDecoration extends RecyclerView.ItemDecoration {
    private static final String TAG = "DividerItemDecoration";

    private static final int[] ATTRS = new int[]{
            android.R.attr.listDivider
    };

    public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL;

    public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL;

    private Drawable mDrawable;

    public DividerItemDecoration(Context context) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDrawable = a.getDrawable(0);
        a.recycle();
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent) {
        if (getLayoutManagerType(parent) == VERTICAL_LIST) {
            drawVertical(c, parent);
        } else {
            drawHorizontal(c, parent);
        }
    }

    private int getLayoutManagerType(RecyclerView rv) {
        RecyclerView.LayoutManager manager = rv.getLayoutManager();

        if (!(manager instanceof LinearLayoutManager)) {
            throw new IllegalArgumentException("only supply linearLayoutManager");
        }

        return ((LinearLayoutManager) manager).getOrientation();
    }

    public void drawVertical(Canvas c, RecyclerView parent) {
        final int left = parent.getPaddingLeft();
        final int right = parent.getWidth() - parent.getPaddingRight();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int top = child.getBottom() + params.bottomMargin;
            final int bottom = top + mDrawable.getIntrinsicHeight();
            mDrawable.setBounds(left, top, right, bottom);
            mDrawable.draw(c);
        }
    }

    public void drawHorizontal(Canvas c, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getHeight() - parent.getPaddingBottom();

        final int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child
                    .getLayoutParams();
            final int left = child.getRight() + params.rightMargin;
            final int right = left + mDrawable.getIntrinsicHeight();
            mDrawable.setBounds(left, top, right, bottom);
            mDrawable.draw(c);
        }
    }

    @Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (getLayoutManagerType(parent) == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDrawable.getIntrinsicHeight());
        } else {
            outRect.set(0, 0, mDrawable.getIntrinsicWidth(), 0);
        }
    }
}
