<?php
/**
 * @package   Gantry5
 * @author    RocketTheme http://www.rockettheme.com
 * @copyright Copyright (C) 2007 - 2017 RocketTheme, LLC
 * @license   GNU/GPLv2 and later
 *
 * http://www.gnu.org/licenses/gpl-2.0.html
 */

namespace Gantry\WordPress;

abstract class Utilities
{
    static function truncate($text, $length = 100, $ending = '&hellip;', $exact = false, $considerHtml = true)
    {
        if (!function_exists('mb_strlen')) {
            return static::truncateCompat($text, $length, $ending, $exact, $considerHtml);
        }

        return static::truncateUtf8($text, $length, $ending, $exact, $considerHtml);
    }

    /**
     * Truncates text. UTF8 compatible version.
     *
     * Cuts a string to the length of $length and replaces the last characters
     * with the ending if the text is longer than length.
     *
     * See: oikos.org.uk/2013/02/tech-notes-a-wordpress-excerpt-with-html-tags/
     * See also: wpengineer.com/2410/dont-use-strlen/
     * See also also: oikos.org.uk/2013/02/tech-notes-a-wordpress-excerpt-with-html-tags/#comment-1467093876
     *
     * @param string  $text         String to truncate.
     * @param integer $length       Length of returned string, including ellipsis.
     * @param string  $ending       Ending to be appended to the trimmed string.
     * @param boolean $exact        If false, $text will not be cut mid-word
     * @param boolean $considerHtml If true, HTML tags would be handled correctly
     *
     * @return string Trimmed string.
     */
    static function truncateUtf8($text, $length = 100, $ending = '&hellip;', $exact = false, $considerHtml = true)
    {
        $open_tags = [];

        if ($considerHtml) {
            // if the plain text is shorter than the maximum length, return the whole text
            if (mb_strlen(preg_replace(array('/<.*?>/', '/\n/', '/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/iu'), array('', '', ' '), $text))
                <= $length
            ) {
                return $text;
            }

            // splits all html-tags to scanable lines
            preg_match_all('/(<.+?>)?([^<>]*)/us', $text, $lines, PREG_SET_ORDER);

            $total_length = ($ending === '&hellip;') ? 2 : mb_strlen($ending);
            $truncate     = '';

            foreach ($lines as $line_matchings) {
                // if there is any html-tag in this line, handle it and add it (uncounted) to the output
                if (!empty($line_matchings[1])) {
                    // if it's an "empty element" with or without xhtml-conform closing slash (f.e. <br/>)
                    if (preg_match('/^<(\s*.+?\/\s*|\s*(img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param)(\s.+?)?)>$/ius',
                        $line_matchings[1])) {
                        // do nothing
                        // if tag is a closing tag (f.e. </b>)
                    } else if (preg_match('/^<\s*\/([^\s]+?)\s*>$/us', $line_matchings[1], $tag_matchings)) {
                        // delete tag from $open_tags list
                        $pos = array_search($tag_matchings[1], $open_tags);
                        if ($pos !== false) {
                            unset($open_tags[$pos]);
                        }
                        // if tag is an opening tag (f.e. <b>)
                    } else if (preg_match('/^<\s*([^\s>!]+).*?>$/us', $line_matchings[1], $tag_matchings)) {
                        // add tag to the beginning of $open_tags list
                        array_unshift($open_tags, strtolower($tag_matchings[1]));
                    }
                    // add html-tag to $truncate'd text
                    $truncate .= $line_matchings[1];
                }

                // calculate the length of the plain text part of the line; handle entities as one character
                $content_length = mb_strlen(preg_replace('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/ui', ' ', $line_matchings[2]));
                if ($total_length + $content_length > $length) {
                    // the number of characters which are left
                    $left            = $length - $total_length;
                    $entities_length = 0;
                    // search for html entities
                    if (preg_match_all('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/ui', $line_matchings[2], $entities, PREG_OFFSET_CAPTURE)) {
                        // calculate the real length of all entities in the legal range
                        foreach ($entities[0] as $entity) {
                            if ($entity[1] + 1 - $entities_length <= $left) {
                                $left--;
                                $entities_length += mb_strlen($entity[0]);
                            } else {
                                // no more characters left
                                break;
                            }
                        }
                    }
                    $truncate .= mb_substr($line_matchings[2], 0, $left + $entities_length);
                    // maximum length is reached, so get off the loop
                    break;
                } else {
                    $truncate .= $line_matchings[2];
                    $total_length += $content_length;
                }

                // if the maximum length is reached, get off the loop
                if ($total_length >= $length) {
                    break;
                }
            }
        } else {
            if (mb_strlen($text) <= $length) {
                return $text;
            } else {
                $truncate = mb_substr($text, 0, $length - mb_strlen($ending));
            }
        }

        // if the words shouldn't be cut in the middle...
        if (!$exact) {
            // ...search the last occurance of a space...
            $spacepos = mb_strrpos($truncate, ' ');
            if (isset($spacepos)) {
                // ...and cut the text in this position
                $truncate = mb_substr($truncate, 0, $spacepos);
            }
        }

        // add the defined ending to the text
        $truncate .= $ending;

        if ($considerHtml) {
            // close all unclosed html-tags
            foreach ($open_tags as $tag) {
                $truncate .= '</' . $tag . '>';
            }
        }

        return $truncate;
    }

    /**
     * Truncates text.
     *
     * Cuts a string to the length of $length and replaces the last characters
     * with the ending if the text is longer than length.
     *
     * See: oikos.org.uk/2013/02/tech-notes-a-wordpress-excerpt-with-html-tags/
     * See also: wpengineer.com/2410/dont-use-strlen/
     * See also also: oikos.org.uk/2013/02/tech-notes-a-wordpress-excerpt-with-html-tags/#comment-1467093876
     *
     * @param string  $text         String to truncate.
     * @param integer $length       Length of returned string, including ellipsis.
     * @param string  $ending       Ending to be appended to the trimmed string.
     * @param boolean $exact        If false, $text will not be cut mid-word
     * @param boolean $considerHtml If true, HTML tags would be handled correctly
     *
     * @return string Trimmed string.
     */
    static function truncateCompat($text, $length = 100, $ending = '&hellip;', $exact = false, $considerHtml = true)
    {
        $open_tags = [];

        if ($considerHtml) {
            // if the plain text is shorter than the maximum length, return the whole text
            if (strlen(utf8_decode(preg_replace(array('/<.*?>/', '/\n/', '/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i'), array('', '', ' '), $text)))
                <= $length
            ) {
                return $text;
            }

            // splits all html-tags to scanable lines
            preg_match_all('/(<.+?>)?([^<>]*)/s', $text, $lines, PREG_SET_ORDER);

            $total_length = ($ending === '&hellip;') ? 2 : strlen(utf8_decode($ending));
            $truncate     = '';

            foreach ($lines as $line_matchings) {
                // if there is any html-tag in this line, handle it and add it (uncounted) to the output
                if (!empty($line_matchings[1])) {
                    // if it's an "empty element" with or without xhtml-conform closing slash (f.e. <br/>)
                    if (preg_match('/^<(\s*.+?\/\s*|\s*(img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param)(\s.+?)?)>$/is',
                        $line_matchings[1])) {
                        // do nothing
                        // if tag is a closing tag (f.e. </b>)
                    } else if (preg_match('/^<\s*\/([^\s]+?)\s*>$/s', $line_matchings[1], $tag_matchings)) {
                        // delete tag from $open_tags list
                        $pos = array_search($tag_matchings[1], $open_tags);
                        if ($pos !== false) {
                            unset($open_tags[$pos]);
                        }
                        // if tag is an opening tag (f.e. <b>)
                    } else if (preg_match('/^<\s*([^\s>!]+).*?>$/s', $line_matchings[1], $tag_matchings)) {
                        // add tag to the beginning of $open_tags list
                        array_unshift($open_tags, strtolower($tag_matchings[1]));
                    }
                    // add html-tag to $truncate'd text
                    $truncate .= $line_matchings[1];
                }

                // calculate the length of the plain text part of the line; handle entities as one character
                $content_length = strlen(utf8_decode(preg_replace('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', ' ', $line_matchings[2])));
                if ($total_length + $content_length > $length) {
                    // the number of characters which are left
                    $left            = $length - $total_length;
                    $entities_length = 0;
                    // search for html entities
                    if (preg_match_all('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', $line_matchings[2], $entities, PREG_OFFSET_CAPTURE)) {
                        // calculate the real length of all entities in the legal range
                        foreach ($entities[0] as $entity) {
                            if ($entity[1] + 1 - $entities_length <= $left) {
                                $left--;
                                $entities_length += strlen(utf8_decode($entity[0]));
                            } else {
                                // no more characters left
                                break;
                            }
                        }
                    }
                    $truncate .= substr($line_matchings[2], 0, $left + $entities_length);
                    // maximum length is reached, so get off the loop
                    break;
                } else {
                    $truncate .= $line_matchings[2];
                    $total_length += $content_length;
                }

                // if the maximum length is reached, get off the loop
                if ($total_length >= $length) {
                    break;
                }
            }
        } else {
            if (strlen(utf8_decode($text)) <= $length) {
                return $text;
            } else {
                $truncate = substr($text, 0, $length - strlen(utf8_decode($ending)));
            }
        }

        // if the words shouldn't be cut in the middle...
        if (!$exact) {
            // ...search the last occurance of a space...
            $spacepos = strrpos($truncate, ' ');
            if (isset($spacepos)) {
                // ...and cut the text in this position
                $truncate = substr($truncate, 0, $spacepos);
            }
        }

        // add the defined ending to the text
        $truncate .= $ending;

        if ($considerHtml) {
            // close all unclosed html-tags
            foreach ($open_tags as $tag) {
                $truncate .= '</' . $tag . '>';
            }
        }

        return $truncate;

    }

}
