<?php

namespace App\Parser\HtmlParser;

use DOMDocument;
use Illuminate\Support\Facades\Log;

class ParseHtml
{

    public function fromUploadedFile($file)
    {
        try {
            $htmlDom = new DomDocument();
            Log::info('Parse html from file:'.$file);
            $htmlString = file_get_contents($file);
            libxml_use_internal_errors(true);
            $htmlDom->loadHTML($htmlString);
            $htmlDom->preserveWhiteSpace = false;

            return $this->parseLoadedHtml($htmlDom);
        } catch (\Exception $exception) {
            dd($exception);
        }
    }


    private function parseLoadedHtml($htmlDom)
    {
        $response            = [];
        $page                = $htmlDom->getElementsByTagName("body")[ 0 ];
        $dataStructuredArray = $this->buildTheParsedResponse($this->domToArray($page));
        foreach ($dataStructuredArray as $index => $item) {
            if (isset($item[ '_type' ]) && $item[ '_type' ] !== 'table') {
                $data = $this->handleChildrens($item);
                if (isset($data[ 'content' ])) {

                    $data[ 'content' ]       = $this->closetags($data[ 'content' ]);
                    $data[ 'clean_content' ] = preg_replace("/(\r\n|\t|\r|\n)+/", " ", strip_tags($data[ 'content' ]));
                    $response[]              = $data;
                }
            }

        }

        return $this->fixChildrenStructure($response);
    }


    private function domToArray($root)
    {
        $result = [];

        //handle classic node
        if ($root->nodeType == XML_ELEMENT_NODE) {
            $result[ '_type' ] = $root->nodeName;
            if ($root->nodeName === 'ol') {
                if ($root->hasAttribute('start')) {
                    $result[ '_startFrom' ] = $root->getAttribute('start');
                } else {
                    $result[ '_startFrom' ] = 1;
                }
            }
            $result[ '_numberOfChildren' ] = $root->childNodes->length;
            if ($root->hasChildNodes()) {
                $children = $root->childNodes;
                for ($i = 0; $i < $children->length; $i++) {
                    $child = $this->domToArray($children->item($i));

                    //don't keep textnode with only spaces and newline
                    if (! empty($child)) {
                        $result[ '_children' ][] = $child;
                    }
                }
            }

            //handle text node
        } elseif ($root->nodeType == XML_TEXT_NODE || $root->nodeType == XML_CDATA_SECTION_NODE) {
            $value = $root->nodeValue;
            if (! empty($value)) {
                $cleanText = preg_replace("/(\r\n|\t|\r|\n)+/", " ", $value);
                if (! empty(str_replace(' ', '', $cleanText))) {
                    $result[ '_type' ]    = '_text';
                    $result[ '_content' ] = ltrim($cleanText);
                }

            }
        }

        //list attributes
        if ($root->hasAttributes()) {
            foreach ($root->attributes as $attribute) {
                $result[ '_attributes' ][ $attribute->name ] = $attribute->value;
            }
        }

        return $result;
    }


    private function buildTheParsedResponse(array $htmElementsAsArray): array
    {
        $parsedResponse = [];
        foreach ($htmElementsAsArray[ '_children' ] as $index => $elementArray) {
            $data = [];
            if ($elementArray[ '_type' ] === '_text') {
                $data[ '_type' ]   = $elementArray[ '_type' ];
                $data[ 'content' ] = $this->parseParagraph($elementArray);
            } elseif (isset($elementArray[ '_children' ])) {


                $parsedResponseData = $this->buildTheParsedResponse($elementArray);
                if (! empty($parsedResponseData)) {
                    $data[ '_type' ] = $elementArray[ '_type' ];
                    if (in_array($elementArray[ '_type' ], ['ul', 'ol'])) {
                        if (isset($elementArray[ '_startFrom' ])) {
                            $data[ 'start' ] = $elementArray[ '_startFrom' ];
                        }
                        $data [ 'children' ] = $parsedResponseData;
                    } else {

                        $data [ 'content' ] = $parsedResponseData;
                    }

                }

            }
            if (! empty($data)) {
                if (isset($elementArray[ '_attributes' ])) {
                    $data[ '_attributes' ] = $elementArray[ '_attributes' ];
                }
                $parsedResponse[] = $data;
            }
        }

        return $parsedResponse;
    }


    private function remove_empty_tags_recursive($str, $repto = null)
    {
        //** Return if string not given or empty.
        if (! is_string($str) || trim($str) == '') {
            return $str;
        }

        //** Recursive empty HTML tags.
        return preg_replace(

        //** Pattern written by Junaid Atari.
            '/<([^<\/>]*)>([\s]*?|(?R))<\/\1>/imsU',

            //** Replace with nothing if string empty.
            ! is_string($repto) ? '' : $repto,

            //** Source string
            $str);
    }


    private function closetags($text)
    {
        $tagstack  = [];
        $stacksize = 0;
        $tagqueue  = '';
        $newtext   = '';
        // Known single-entity/self-closing tags.
        $single_tags = [
            'area',
            'base',
            'basefont',
            'br',
            'col',
            'command',
            'embed',
            'frame',
            'hr',
            'img',
            'input',
            'isindex',
            'link',
            'meta',
            'param',
            'source'
        ];
        // Tags that can be immediately nested within themselves.
        $nestable_tags = ['blockquote', 'div', 'object', 'q', 'span'];

        // WP bug fix for comments - in case you REALLY meant to type '< !--'.
        $text = str_replace('< !--', '<    !--', $text);
        // WP bug fix for LOVE <3 (and other situations with '<' before a number).
        $text = preg_replace('#<([0-9]{1})#', '&lt;$1', $text);

        /**
         * Matches supported tags.
         *
         * To get the pattern as a string without the comments paste into a PHP
         * REPL like `php -a`.
         *
         * @see https://html.spec.whatwg.org/#elements-2
         * @see https://w3c.github.io/webcomponents/spec/custom/#valid-custom-element-name
         *
         * @example
         * ~# php -a
         * php > $s = [paste copied contents of expression below including parentheses];
         * php > echo $s;
         */
        $tag_pattern = ('#<'. // Start with an opening bracket.
            '(/?)'. // Group 1 - If it's a closing tag it'll have a leading slash.
            '('. // Group 2 - Tag name.
            // Custom element tags have more lenient rules than HTML tag names.
            '(?:[a-z](?:[a-z0-9._]*)-(?:[a-z0-9._-]+)+)'.'|'.// Traditional tag rules approximate HTML tag names.
            '(?:[\w:]+)'.')'.'(?:'.// We either immediately close the tag with its '>' and have nothing here.
            '\s*'.'(/?)'. // Group 3 - "attributes" for empty tag.
            '|'.// Or we must start with space characters to separate the tag name from the attributes (or whitespace).
            '(\s+)'. // Group 4 - Pre-attribute whitespace.
            '([^>]*)'. // Group 5 - Attributes.
            ')'.'>#' // End with a closing bracket.
        );

        while (preg_match($tag_pattern, $text, $regex)) {
            $full_match        = $regex[ 0 ];
            $has_leading_slash = ! empty($regex[ 1 ]);
            $tag_name          = $regex[ 2 ];
            $tag               = strtolower($tag_name);
            $is_single_tag     = in_array($tag, $single_tags, true);
            $pre_attribute_ws  = isset($regex[ 4 ]) ? $regex[ 4 ] : '';
            $attributes        = trim(isset($regex[ 5 ]) ? $regex[ 5 ] : $regex[ 3 ]);
            $has_self_closer   = '/' === substr($attributes, -1);

            $newtext .= $tagqueue;

            $i = strpos($text, $full_match);
            $l = strlen($full_match);

            // Clear the shifter.
            $tagqueue = '';
            if ($has_leading_slash) { // End tag.
                // If too many closing tags.
                if ($stacksize <= 0) {
                    $tag = '';
                    // Or close to be safe $tag = '/' . $tag.

                    // If stacktop value = tag close value, then pop.
                } elseif ($tagstack[ $stacksize - 1 ] === $tag) { // Found closing tag.
                    $tag = '</'.$tag.'>'; // Close tag.
                    array_pop($tagstack);
                    $stacksize--;
                } else { // Closing tag not at top, search for it.
                    for ($j = $stacksize - 1; $j >= 0; $j--) {
                        if ($tagstack[ $j ] === $tag) {
                            // Add tag to tagqueue.
                            for ($k = $stacksize - 1; $k >= $j; $k--) {
                                $tagqueue .= '</'.array_pop($tagstack).'>';
                                $stacksize--;
                            }
                            break;
                        }
                    }
                    $tag = '';
                }
            } else { // Begin tag.
                if ($has_self_closer) { // If it presents itself as a self-closing tag...
                    // ...but it isn't a known single-entity self-closing tag, then don't let it be treated as such
                    // and immediately close it with a closing tag (the tag will encapsulate no text as a result).
                    if (! $is_single_tag) {
                        $attributes = trim(substr($attributes, 0, -1))."></$tag";
                    }
                } elseif ($is_single_tag) { // Else if it's a known single-entity tag but it doesn't close itself, do so.
                    $pre_attribute_ws = ' ';
                    $attributes       .= '/';
                } else { // It's not a single-entity tag.
                    // If the top of the stack is the same as the tag we want to push, close previous tag.
                    if ($stacksize > 0 && ! in_array($tag, $nestable_tags,
                            true) && $tagstack[ $stacksize - 1 ] === $tag) {
                        $tagqueue = '</'.array_pop($tagstack).'>';
                        $stacksize--;
                    }
                    $stacksize = array_push($tagstack, $tag);
                }

                // Attributes.
                if ($has_self_closer && $is_single_tag) {
                    // We need some space - avoid <br/> and prefer <br />.
                    $pre_attribute_ws = ' ';
                }

                $tag = '<'.$tag.$pre_attribute_ws.$attributes.'>';
                // If already queuing a close tag, then put this tag on too.
                if (! empty($tagqueue)) {
                    $tagqueue .= $tag;
                    $tag      = '';
                }
            }
            $newtext .= substr($text, 0, $i).$tag;
            $text    = substr($text, $i + $l);
        }

        // Clear tag queue.
        $newtext .= $tagqueue;

        // Add remaining text.
        $newtext .= $text;

        while ($x = array_pop($tagstack)) {
            $newtext .= '</'.$x.'>'; // Add remaining tags to close.
        }

        // WP fix for the bug with HTML comments.
        $newtext = str_replace('< !--', '<!--', $newtext);
        $newtext = str_replace('<    !--', '< !--', $newtext);

        return $this->remove_empty_tags_recursive($newtext);
    }


    private function parseParagraph($elementArray, $type = null, $number = null)
    {
        $data = [];

        $data[ '_content' ] = ($type) ? $this->closetags(implode('',
                $type).$elementArray[ '_content' ]) : $elementArray[ '_content' ];

        return $data;
    }


    private function handleChildrens($data, $parsed = [])
    {
        if ($data[ '_type' ] !== 'table') {

            $parsed[ 'content' ] = '<'.$data[ '_type' ].'>';
            if (in_array($data[ '_type' ], ['ol', 'ul'])) {
                $parsed[ 'children' ] = [];
                if (isset($data[ 'start' ])) {
                    $startFrom = $data[ 'start' ];
                }

                foreach ($data[ 'children' ] as $child) {
                    if (isset($child[ 'start' ])) {
                        $startFrom = $child[ 'start' ];
                    }
                    if (isset($child[ 'content' ])) {
                        foreach ($child[ 'content' ] as $li) {
                            $data = $this->handleChildrens($li);
                            if (isset($data[ 'content' ])) {
                                $data[ 'clean_content' ] = preg_replace("/(\r\n|\t|\r|\n)+/", " ",
                                    strip_tags($data[ 'content' ]));
                                if (isset($startFrom) && strlen(trim($data[ 'clean_content' ])) > 0) {
                                    $data[ 'numbering_row' ] = $startFrom;
                                    $startFrom++;
                                }

                                $parsed[ 'children' ][] = $data;
                            }

                        }
                    } else {
                        $data                    = $this->handleChildrens($child);
                        $data[ 'clean_content' ] = preg_replace("/(\r\n|\t|\r|\n)+/", " ",
                            strip_tags($data[ 'content' ]));
                        $parsed[ 'children' ][]  = $data;
                    }
                }
            } elseif (isset($data[ '_type' ]) && ($data[ '_type' ] === 'div')) {
                foreach ($data[ 'content' ] as $child) {
                    $data = $this->handleChildrens($child);
                    if (isset($data[ 'content' ])) {
                        $data[ 'clean_content' ] = preg_replace("/(\r\n|\t|\r|\n)+/", " ",
                            strip_tags($data[ 'content' ]));
                        $data[ 'content' ]       = $this->closetags($data[ 'content' ]);
                    }

                    $parsed[ 'children' ][] = $data;
                }

            } else {
                $contentChilds = count($data[ 'content' ]);
                foreach ($data[ 'content' ] as $index => $child) {
                    if ($child[ '_type' ] !== '_text') {
                        if (! isset($parsed[ 'content' ])) {
                            $parsed[ 'content' ] = '<'.$child[ '_type' ].'>';
                        } else {
                            $parsed[ 'content' ] .= '<'.$child[ '_type' ].'>';

                        }
                        $childs = $this->handleChildrens($child, $parsed);
                        if ($childs && isset($child[ 'content' ])) {
                            $parsed[ 'content' ] .= $childs[ 'content' ];
                        }

                    } else {
                        if (! isset($parsed[ 'content' ])) {
                            $parsed[ 'content' ] = $child[ 'content' ][ '_content' ];
                        } else {
                            $parsed[ 'content' ] .= $child[ 'content' ][ '_content' ];
                        }
                    }
                    if ($contentChilds == $index + 1) {
                        $parsed[ 'content' ] = $this->closetags($parsed[ 'content' ]);
                    }
                    $parsed[ 'children' ] = [];
                }
            }

            return $parsed;
        }

    }


    private function fixChildrenStructure($data)
    {

        $result = [];
        $alreadyHandledIndexes = [];

        for ($i = 0; $i < count($data); $i++) {

            if (isset($data[ $i ][ 'content' ]) && $data[ $i ][ 'content' ] == '<ol>') {
                $alreadyHandledIndexes[] = $i;
                continue;
            }
            if (array_key_exists($i, $alreadyHandledIndexes)) {
                continue;
            }

            if(isset($data[ $i ]['content']) && $data[ $i ]['content']==='' && count($data[ $i ]['children'])==1){
                $data[ $i ] = last($data[ $i ]['children']);
            }


            $j = $i + 1;
            for ($j; $j < count($data); $j++) {
                if (array_key_exists($i, $alreadyHandledIndexes)) {
                    continue;
                }

                if (! isset($data[ $j ][ 'content' ]) || strpos($data[ $j ][ 'content' ], 'h1') !== false) {
                    break;
                }

                if(isset($data[$i]['numbering_row'])){
                    $data[ $i ] = $this->handlePossibleChild($data[ $i ], $data[ $j ]);
                    $alreadyHandledIndexes[] = $j;

                }else {
                    break;
                }


            }

            //if (isset($data[ $i ][ 'content' ]) && empty($data[ $i ][ 'content' ])) {
            //    $data[ $i ] = last($data[ $i ][ 'children' ]);
            //}
            if (is_array($data[ $i ]) && count($data[ $i ]) > 1 && ! isset($data[ $i ][ 'content' ])) {
                $result = array_merge($result, $data[ $i ]);
            } else {
                $result[] = $data[ $i ];
            }

            $alreadyHandledIndexes[] = $i;

        }

        return $result;
    }


    private function handlePossibleChild($parent, $child = [])
    {

        if($child['content']===''){
            dd($parent);
        }


        if (isset($parent[ 'children' ])) {
            if (empty($parent[ 'content' ]) && count($parent[ 'children' ]) === 1) {

                $parent = $parent[ 'children' ][ 0 ];
            } elseif (empty($parent[ 'content' ]) && count($parent[ 'children' ]) > 1) {
                $parent = $this->fixChildrenStructure($parent[ 'children' ]);
            }


        }

        if (isset($child[ 'content' ]) && $child[ 'content' ] == '<ol>') {
            for ($i = 0; $i < count($child[ 'children' ]); $i++) {
                $newChild = $child[ 'children' ][ $i ];
                if ($child[ 'children' ][ $i ][ 'content' ] == '<ol>') {
                    $lastParentChild = last($parent[ 'children' ]);

                    $newChild = $this->handlePossibleChild($lastParentChild, $child[ 'children' ][ $i ]);
                }

                $parent[ 'children' ][] = $newChild;

            }

            //return $parent;

        }


        if (isset($parent[ 'clean_content' ]) && strlen($parent[ 'clean_content' ]) && strpbrk(substr($parent[ 'clean_content' ],
                -1), '.,;\'"0123456789') === false && ctype_lower(substr($parent[ 'clean_content' ],
                -1)) && isset($child[ 'clean_content' ]) && strlen($child[ 'clean_content' ])) {
            $parent[ 'content' ]       .= ' '.$child[ 'content' ];
            $parent[ 'children' ]      = array_merge($parent[ 'children' ], $child[ 'children' ]);
            $parent[ 'clean_content' ] .= ' '.$child[ 'clean_content' ];

        }

        if (is_array($parent) && count($parent) == 1 && ! isset($parent[ 'content' ])) {
            $parent = array_shift($parent);
        }


        return $parent;
    }

}