/*
 * Copyright 2018 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.cannonball.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import com.google.cannonball.R;

public class FlowLayout extends ViewGroup {
    private int paddingHorizontal;
    private int paddingVertical;

    public FlowLayout(Context context) {
        super(context);
        init();
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public FlowLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    private void init() {
        paddingHorizontal = getResources().getDimensionPixelSize(R.dimen.word_padding_horizontal);
        paddingVertical = getResources().getDimensionPixelSize(R.dimen.word_padding_vertical);
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lineHeight = 0;
        final int myWidth = right - left;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            final int childWidth = child.getMeasuredWidth();
            final int childHeight = child.getMeasuredHeight();
            lineHeight = Math.max(childHeight, lineHeight);
            if (childWidth + childLeft + getPaddingRight() > myWidth) {
                childLeft = getPaddingLeft();
                childTop += paddingVertical + lineHeight;
                lineHeight = childHeight;
            }
            child.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
            childLeft += childWidth + paddingHorizontal;
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int childLeft = getPaddingLeft();
        int childTop = getPaddingTop();
        int lineHeight = 0;
        // 100 is a dummy number, widthMeasureSpec should always be EXACTLY for FlowLayout
        final int myWidth = resolveSize(100, widthMeasureSpec);
        int wantedHeight = 0;
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() == View.GONE) {
                continue;
            }
            // let the child measure itself
            child.measure(
                    getChildMeasureSpec(widthMeasureSpec, getPaddingLeft() + getPaddingRight(),
                            child.getLayoutParams().width),
                    getChildMeasureSpec(heightMeasureSpec, getPaddingTop() + getPaddingBottom(),
                            child.getLayoutParams().height));
            final int childWidth = child.getMeasuredWidth();
            final int childHeight = child.getMeasuredHeight();
            // lineheight is the height of current line, should be the height of the heightest view
            lineHeight = Math.max(childHeight, lineHeight);
            if (childWidth + childLeft + getPaddingRight() > myWidth) {
                // wrap this line
                childLeft = getPaddingLeft();
                childTop += paddingVertical + lineHeight;
                lineHeight = childHeight;
            }
            childLeft += childWidth + paddingHorizontal;
        }
        wantedHeight += childTop + lineHeight + getPaddingBottom();
        setMeasuredDimension(myWidth, resolveSize(wantedHeight, heightMeasureSpec));
    }
}