Font.php

<?php
namespace Crayon;

use const Crayon\{RED, GREEN, BLUE, YELLOW, MAGENTA, CYAN};

/**
 * Class Font
 *
 * A string representation class which contains all formatting information
 * that'll be used when rendering the string.
 *
 * @package Crayon
 */
class Font
{
    /**
     * @var string
     */
    const BOLD = "\e[1m";

    /**
     * @var string
     */
    const ITALIC = "\e[3m";

    /**
     * @var string
     */
    const UNDERLINE = "\e[4m";

    /**
     * @var string
     */
    const RESET = "\e[0m";

    /**
     * the text to be formatted
     * @var string|null
     */
    private $text;

    /**
     * boolean value to indicate if the text shall be rendered bold
     * @var bool
     */
    private $bold = false;

    /**
     * boolean value to indicate if the text shall be rendered italic
     * @var bool
     */
    private $italic = false;

    /**
     * boolean value to indicate if the text shall be rendered underlined
     * @var bool
     */
    private $underline = false;

    /**
     * may contain the color format string if available
     * @var string|null
     */
    private $color;

    /**
     * sets the information that the color should be applied as background
     * @var bool
     */
    private $background = false;

    /**
     * Font constructor.
     * @param string $text
     */
    public function __construct(string $text)
    {
        $this->text = $text;
    }

    /**
     * function to set text bold
     * @return Font
     */
    public function bold(): Font
    {
        $this->bold = true;
        return $this;
    }

    /**
     * function to set text italic
     * @return Font
     */
    public function italic(): Font
    {
        $this->italic = true;
        return $this;
    }

    /**
     * function to set text underlined
     * @return Font
     */
    public function underline(): Font
    {
        $this->underline = true;
        return $this;
    }

    /**
     * function to color the text red
     * @return Font
     */
    public function red(): Font
    {
        return $this->color(RED);
    }

    /**
     * function to color the text green
     * @return Font
     */
    public function green(): Font
    {
        return $this->color(GREEN);
    }

    /**
     * function to color the text yellow
     * @return Font
     */
    public function yellow(): Font
    {
        return $this->color(YELLOW);
    }

    /**
     * function to color the text blue
     * @return Font
     */
    public function blue(): Font
    {
        return $this->color(BLUE);
    }

    /**
     * function to color the magenta
     * @return Font
     */
    public function magenta(): Font
    {
        return $this->color(MAGENTA);
    }

    /**
     * function to color the text cyan
     * @return Font
     */
    public function cyan(): Font
    {
        return $this->color(CYAN);
    }

    /**
     * function to set color as background
     * @return Font
     */
    public function background(): Font
    {
        if ($this->color !== null) {
            $this->turnToBackground();
        }

        $this->background = true;
        return $this;
    }

    /**
     * function to prepare and render the text with set font options
     * @return string
     */
    public function __toString()
    {
        $reset = self::RESET;

        $font_color = $this->color ?? '';
        $is_bold = $this->bold ? self::BOLD : '';
        $is_italic = $this->italic ? self::ITALIC : '';
        $is_underline = $this->underline ? self::UNDERLINE : '';

        return "{$font_color}{$is_bold}{$is_italic}{$is_underline}{$this->text}{$reset}";
    }

    /**
     * function to set color to a string
     * @param string $color
     * @return Font
     */
    private function color(string $color): Font
    {
        $this->color = $color;

        if ($this->background) {
            $this->turnToBackground();
        }

        return $this;
    }

    /**
     * function to convert color to background color
     */
    private function turnToBackground()
    {
        $this->color = preg_replace_callback('/\\e\[(?<color>\d+)m/', function ($matches) {
            $new_color = $matches['color'] + 10;
            return "\e[{$new_color}m";
        }, $this->color);
    }
}