Area Forecast Discussion parser

afd.php

<?php
/**
 * Parse the NWS Area Forecast Discussion (AFD)
 *
 * Adds casing and formating to the AFD, which is published as an
 * all uppercase `<pre>` block with hard line breaks and no formatting.
 * 
 * Usage: <?php $afd = new AreaForecastDiscussion("BOX"); echo $afd->generateHTML(); ?>
*/
class AreaForecastDiscussion {
    const NEEDLE_META      = "/^[0-9]{3}?$\\n^.*?$\\n^.*?$\\n\\n/m";
    const NEEDLE_HEADERS   = "/^AREA FORECAST DISCUSSION?$\\n^.*?$\\n^.*?$\\n\\n/m";
    const NEEDLE_SYNOPSIS  = "/^\\.SYNOPSIS\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_NEARTERM  = "/^\\.NEAR TERM.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_SHORTTERM = "/^\\.SHORT TERM.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_LONGTERM  = "/^\\.LONG TERM.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_AVIATION  = "/^\\.AVIATION.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_MARINE    = "/^\\.MARINE.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_BOX       = "/^\\.BOX WATCHES.*?\\.\\.\\.$.*?^&&$/sm";
    const NEEDLE_AUTHORS   = "/^\\$\\$.*/ms";
    const DAYS             = "/Sunday|Monday|Tuesday|Wednesday|Thursday|Friday|Saturday/i";
    const SECTIONS         = "META,HEADERS,SYNOPSIS,NEARTERM,SHORTTERM,LONGTERM,AVIATION,MARINE,BOX,AUTHORS";
    const AFD_BASEURL      = 'http://forecast.weather.gov/product.php?product=AFD&format=TXT&version=1&site=%1$s&issuedby=%1$s';
    public $sections       = array();
    public $meta           = array();
    public $afd            = "";
    public $location       = "";

    function __construct($location = "BOX", $sectionsList = self::SECTIONS) {
        $this->location = $location;
        $this->afd = $this->getAfd($location);
        $this->sections = $this->splitSections(explode(",", $sectionsList));
    }

    private function getAfd($location) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, sprintf(self::AFD_BASEURL, $location));
        curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.48 Safari/537.36"); 
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        $response  = curl_exec($ch);
        preg_match("/(<pre.*<\\/pre>)/s", $response, $matches);
        return substr($matches[0], strpos($matches[0], "\n"), -6);
    }
    /**
     * Split the plaintext AFD into sections as follows
     *  * Meta:
     *      .Tracking
     *      .Title
     *      .Authors
     *  * Sections:
     *     .SYNOPSIS
     *     .NEAR TERM
     *     .SHORT TERM
     *     .LONG TERM
     *     .AVIATION
     *     .MARINE
     *     .BOX WATCHES
     *
     * @param  array $sectionsList list of sections to extract
     * @return array               [description]
     */
    private function splitSections($sectionsList) {
        $sections = array();

        foreach ($sectionsList as $section) {
            //Stop trying to be fancy, you don't even know what this does
            try {
                preg_match(constant("self::NEEDLE_$section"), $this->afd, $matches);
            } catch (Exception $e) {
                //do something here
            }
            if(count($matches) == 0) {
                trigger_error ( "Section \"$section\" not found." );
                break;
            }
            
            //TODO: Make this less fragile (e.g. magic #3)
            $isMeta = ( $section == 'META' || $section == 'HEADERS' || $section == 'AUTHORS' ) ? TRUE : FALSE;
            if($isMeta) {
                $this->meta[strtolower($section)] = $matches[0];
            } else {
                $heading = substr($matches[0], 0, strpos($matches[0], "\n"));
                $text    = strtolower(substr($matches[0], strpos($matches[0], "\n")+1,-3));
                $sections[strtolower($section)]["heading"] = $heading;
                $sections[strtolower($section)]["text"]    = $text;
            }
        }

        return $sections;
    }

    public function generateHTML() {
        $html = "";
        
        foreach($this->sections as $section) {
            $heading = $this->formatSectionHeading($section['heading']);
            $text = $this->formatSectionText($section['text']);
            $html .= "<h2>$heading</h2>\n";
            $html .= "<p>$text</p>\n\n";
        }
        return $html;
    }

    private function formatSectionHeading($heading) {
        //Remove dots
        $heading = preg_replace("/^\./", "", preg_replace("/\\.\\.\\.$/", "", $heading));

        //Handle slashes e.g. TITLE /TIME THROUGH TIME/
        if(preg_match("/BOX/",$heading) == 0 && preg_match_all("/\\//", $heading) == 2) {
            $heading = preg_replace("/\\//", "<br />", $heading, 1);
            $heading = preg_replace("/\\//", "", $heading);
        }

        return ucwords(strtolower($heading));
    }

    private function formatSectionText($text) {
        //Casing
        $text = ucfirst($text);
        $text = preg_replace_callback("/^\D|\n\n\D/",               function($matches) {return strtoupper($matches[0]);},   $text);
        $text = preg_replace_callback("/^\n\D/",                    function($matches) {return strtoupper($matches[0]);},   $text);
        $text = preg_replace_callback("/((\.[a-z])|(\.\ [a-z]))/",  function($matches) {return strtoupper($matches[0]);},   $text);
        $text = preg_replace_callback(self::DAYS,                   function($matches) {return ucfirst($matches[0]);},      $text);

        //Breaks
        $text = preg_replace(         "/\n\n/",                     "<br /><br />",                                         $text);
        $text = preg_replace(         "/\\.\\.\\.$/m",              "...<br /><br />",                                      $text);
        $text = preg_replace(         "/confidence\./",             "confidence.<br /><br />",                              $text);

        return $text;
    }
}

$afd = new AreaForecastDiscussion("BOX");
?>
<!DOCTYPE html>
<html>
<head>
<title>AFD</title>
<style>
body {
    margin: 0 auto;
    max-width: 30em;
    font-size: 1.2rem;
    line-height: 1.8rem;
}
</style>
</head>
<body>
<h1>Area Forecast Discussion</h1>
<p><a href="http://forecast.weather.gov/product.php?product=AFD&format=TXT&version=1&site=BOX&issuedby=BOX">From the NWS</a>.</p>
<?php echo $afd->generateHTML(); ?>
</body>
</html>