<?php

abstract class Tag
{
    protected $tag;
    protected $children;
    protected $attributes;

    public function printTag()
    {
        echo "<$this->tag ";

        if ($this->attributes != null) {
            foreach ($this->attributes as $prop => $value) {
                echo $prop . '="' . $value . '" ';
            }
        }
        echo '>';

        if (is_array($this->children)) {
            foreach ($this->children as $child) {

                if ($child instanceof Tag) {
                    $child->printTag();
                } else if (is_string($child)) {
                    echo $child;
                }
            }
        } else if (is_string($this->children)) {
            echo $this->children;
        } else if ($this->children instanceof Tag) {
            $this->children->printTag();
        }

        echo "</$this->tag>";
    }
}

class Tag_Builder extends Tag
{
    public function __construct(string $tag, $children = null, array $attributes = [])
    {
        $this->tag = $tag;

        $this->children = [];
        if (!is_array($children)) {
            $this->addChild($children);
        } else {
            $this->children = $children;
        }

        $this->attributes = $attributes;
    }
    public function getTag(): string
    {
        return $this->tag;
    }
    public function isThisTag(string $tag): bool
    {
        if ($this->tag == $tag) {
            return true;
        }
        return false;
    }

    public function addChild($child, $key = null)
    {
        if (is_null($key)) {
            $this->children[] = $child;
        } else {
            $this->children[$key] = $child;
        }
    }

    public function getChild($key)
    {
        return $this->children[$key];
    }
    public function removeChild($key)
    {
        unset($this->children[$key]);
    }

    public function getChildren()
    {
        $this->children;
    }
    public function addChildren(array $children)
    {
        foreach ($children as $key => $value) {
            $this->children[$key] = $value;
        }
    }
    public function setChildren($children)
    {
        $this->children = $children;
    }
    public function removeChildren(array $keys)
    {
        foreach ($keys as $key) {
            unset($this->children[$key]);
        }
    }


    public function getAttrib(string $key)
    {
        return $this->attributes[$key];
    }
    public function setAttrib(string $key, string $value)
    {
        $this->attributes[$key] = $value;
    }
    public function removeAttrib(string $key)
    {
        unset($this->attribute[$key]);
    }

    public function getAttributes()
    {
        return $this->attributes;
    }
    public function addAttributes(array $attributes)
    {
        foreach ($attributes as $key => $value) {
            $this->attributes[$key] = $value;
        }
    }
    public function setAttributes(array $attributes)
    {
        $this->attributes = $attributes;
    }
    public function removeAttributes(array $keys)
    {
        foreach ($keys as $key) {
            unset($this->attributes[$key]);
        }
    }
}





?>