compile

#!/usr/bin/env php

<?php

// Format and check args
@[$_, $src, $dst, $opt] = $_SERVER['argv'];

if (!$src || !$dst)
    return terminate(['Usage: php compile <source> <destination> [options]', '', 'Options:', ' d - shows defined paragraph number']);

// Check source file and load it
if (!is_file($src))
    return terminate('Soruce file doesn\'t exist!');
$input = file_get_contents($src);

// Create arrays for every type's indexing
$heads = [];
$sections = [];
$paragraphs = [];

// Create variables for current type's ids
$head = 0;
$section = 0;
$paragraph = 0;

// Create tree array and output string
$tree = [];
$output = '';

// Iterate over input file lines
foreach (explode(PHP_EOL, $input) as $line)
{
    // Head
    if (str_contains(str_replace('\\#', '', $line), '#'))
    {
        // Set current head id
        $head = count($heads);
        
        // Add current head to heads array
        $heads[] = trim(str_replace('#', '', $line));
        
        // Create array for sections of this head in tree array
        $tree[$head] = [];
        continue;
    }

    // Section
    if (str_contains(str_replace('\\§', '', $line), '§'))
    {
        // Set current section id
        $section = count($sections);
        
        // Add current section to sections array
        $sections[] = trim(str_replace('§', '', $line));
        
        // Create array for parahraphs of this section in tree array
        $tree[$head][$section] = [];
        continue;
    }
    
    // Paragraph
    if (preg_match('/^\s*(\d+):(.+)/i', $line))
    {
        // Match paragraph's defined position and the paragraph itself 
        $x = preg_replace_callback('/^\s*(\d+):(.+)/i', function ($matches) use ($head, $section, &$paragraph, &$paragraphs, &$tree, $opt) {
            // Unroll matches array
            [$_, $position, $content] = $matches;
            
            // Trim the paragraph
            $content = trim($content);
            
            // Unescape hashes
            $content = str_replace('\\#', '#', $content);
            
            // If debug is on, add defined position to paragraph content
            if (str_contains($opt, 'd'))
                $content = "[$position] " . $content;
            
            // Set current paragraph id to it's position
            $paragraph = count($tree[$head][$section]);
            
            // Add current paragraph to paragraphs array
            $paragraphs[$position] = $content;
            
            // Add current paragraph to tree
            $tree[$head][$section][] = $content;
        }, $line);
        continue;
    }
    
    // New line of paragraph
    if (trim($line))
    {
        // If the line is not ordered list, output two new lines.
        $space = PHP_EOL . (preg_match('/\d\./', $line) ? null : PHP_EOL);
        $paragraphs[$paragraph] .= $space . $line;
        $tree[$head][$section][$paragraph] .= $space . $line;
    }
}

// Create variable for keeping track of last output type
$last = 2;

// Iterate over heads from the tree
foreach ($tree as $head_id => $head_sections)
{
    // If the last head's iteration was finished, output empty line
    if ($last == 0) output();
    
    // Output current head
    output('## Hlava ' . getRomenianNumerals($head_id + 1) . '. - ' . $heads[$head_id]);
    
    // Iterate over sections of current head
    foreach ($head_sections as $section_id => $section_paragraphs)
    {
        // If the last head's iteration was finished, output empty line
        if ($last == 1) output();
        
        // Output current section
        output('### § ' . $section_id + 1 . ' - ' . $sections[$section_id]);
        
        // Iterate over paragraphs of current section
        foreach ($section_paragraphs as $paragraph_id => $iterated_paragraph)
        {
            // Save current paragraph to variable
            $line = $iterated_paragraph;
            
            // Match and replace paragraph mentions
            $line = preg_replace_callback('/(\@)(\d+)/i', function ($matches) use ($paragraphs) {
                // Get mentioned paragraph's defined position
                $mentioned_position = array_pop($matches);
                
                // Get mentioned paragraph
                $mentioned_paragraph = $paragraphs[$mentioned_position];
                
                // Extract paragraph's section id and paragraph id
                [$head_id, $section_id, $paragraph_id] = getPathToParagraph($mentioned_paragraph);
                
                // Replace the paragraph mention with id of the mentioned paragraph and it's section id
                return '§ ' . $section_id + 1 . ' odst. ' . $paragraph_id + 1;
            }, $line);

            // Output current formatted paragraph
            output($paragraph_id + 1 . '. ' . $line);

            // Set last type to paragraph
            $last = 2;
        }     

        // Set last type to section
        $last = 1;
    }

    // Set last type to head
    $last = 0;
}

// Save output to the designated file
file_put_contents($dst, $output);
return terminate('Rules file has been exported successfully! Last paragraph position: ' . count($paragraphs) + 1);

// ------------ Functions ------------

/**
 * Prints formatted exit message.
 *
 * @param string|string[] $message
 * @return string
 */
function terminate($message)
{
    if (is_array($message))
        $message = implode(PHP_EOL, $message);
    return print PHP_EOL . $message . PHP_EOL;
}

/**
 * Iterates over the tree array and finds path to given paragraph.
 *
 * @param string $matching_paragraph
 * @return array|bool
 */
function getPathToParagraph($matching_paragraph)
{
    global $tree;
    foreach ($tree as $head_id => $head_sections)
        foreach ($head_sections as $section_id => $section_paragraphs)
            foreach ($section_paragraphs as $paragraph_id => $iterated_paragraph)
                if ($iterated_paragraph == $matching_paragraph)
                    return [$head_id, $section_id, $paragraph_id];
    return false;
}

/**
 * Adds given argument to output string.
 *
 * @param string $content
 * @return void
 */
function output($content = '')
{
    global $output;
    $output .= $content . PHP_EOL;
}

/**
 * Converts int to romenian numeral.
 * @see https://stackoverflow.com/a/68423305
 *
 * @param int $N
 * @return string
 */
function getRomenianNumerals($N)
{
    $c = 'IVXLCDM';
    for ($a = 5, $b = 0, $s = ''; $N; $b++, $a ^= 7)
        for ($o = $N % $a, $N = $N / $a ^ 0; $o--; )
            $s = $c[$o > 2 ? $b + $N - ($N &= -2) + $o = 1 : $b] . $s;
    return $s;
}