vbbs/app/Classes/Parser.php

<?php

namespace App\Classes;

/**
 * The Frame Parser looks into frames for ESC codes that renders dynamic information
 */
abstract class Parser
{
	// Fields in the frame
	public $fields = [];

	// Magic Fields that are pre-filled
	protected $fieldmap = [
		'a'=>'address#',
		'd'=>'%date',
	];

	// Position array of frame control chars
	protected $frame_data = [];

	// Position array of frame chars
	protected $frame_content = [];

	// Parsed frame, ready to send to client
	public $output = '';

	public function __construct(string $content,int $width,int $startline=1)
	{
		$this->fields = collect();
		$this->output = $this->parse($startline,$content,$width);
	}

	public function __toString(): string
	{
		return $this->output;
	}

	/**
	 * Return the character at a specific position
	 *
	 * @param int $x
	 * @param int $y
	 * @return string
	 */
	public function char(int $x,int $y): string
	{
		$y += 1;

		return (isset($this->frame_content[$y]) AND isset($this->frame_content[$y][$x]))
			? $this->frame_content[$y][$x]
			: ' ';
	}

	public function attr(int $x,int $y)
	{
		$y += 1;

		return (isset($this->frame_data[$y]) AND isset($this->frame_data[$y][$x]))
			? implode(';',$this->frame_data[$y][$x]).'m'
			: '-';
	}

	abstract protected function parse(int $startline,string $content,int $width): string;
}