<?php

/**
 * RSS Article URL Extractor
 *
 * This script is designed to fetch and extract article URLs from the RSS feeds of various French media outlets.
 * The sources of these RSS feeds are stored in the `base_media` table of the database.
 * For each source, the script retrieves the RSS content, processes each entry, and stores the article URLs 
 * into the database for further processing or analysis.
 *
 * @author Guillaume Eckendoerffer
 * @date 07-09-2023
 */


// Include the database functions
include( "functions_mysqli.php" );

// Initialize global variables
$last = date("U");
$path = $_SERVER['DOCUMENT_ROOT'];

/**
 * Fetches the latest URL from the database.
 *
 * @param mysqli $mysqli The mysqli connection object.
 * @return array Associative array containing the ID, URL, and the last update time.
 */
function fetchLatestURL( $mysqli ) {
    $result = mysqli_query( $mysqli, "SELECT `id`, `url`, `last` FROM `base_media` ORDER By `last` ASC LIMIT 1" );
    return mysqli_fetch_assoc( $result );
}

/**
 * Updates the last fetched timestamp for the given source.
 *
 * @param mysqli $mysqli The mysqli connection object.
 * @param int $id_source The ID of the source to update.
 * @param int $last The new timestamp.
 */
function updateLastFetched( $mysqli, $id_source, $last ) {
    mysqli_query( $mysqli, "UPDATE `base_media` SET `last`='$last' WHERE `id`='$id_source' LIMIT 1" );
}

/**
 * Fetches the content from a given URL.
 *
 * @param string $url The URL to fetch.
 * @return string The content of the fetched URL.
 */
function fetchURLContent( $url) {
    $data = file_get_contents( trim( $url ) );
    return $data;
}

/**
 * Saves the given content to a file.
 *
 * @param string $path The path where the content should be saved.
 * @param string $data The content to save.
 */
function saveToFile( $path, $data ) {
    $file = fopen( $path, "w" );
    fwrite( $file, $data );
    fclose( $file );
}

/**
 * Processes the fetched RSS content and updates the database accordingly.
 *
 * @param mysqli $mysqli The mysqli connection object.
 * @param string $content The RSS content.
 * @param int $id_source The ID of the source.
 */
function processRSSContent( $mysqli, $content, $id_source ) {
    $a = new SimpleXMLElement( $content );
    $nb = 0;

    // First attempt: Process each item in the channel
    foreach ( $a->channel->item as $entry ) {
        $media = $entry->children( 'media', TRUE );
        $attributes = $media->content->attributes();
        $src = $attributes['url'];
        $url = trim( $entry->link );
        $url = str_replace(strstr( $url, "#"), "", $url );
        $url = str_replace(strstr( $url, "?utm"), "", $url );
        $url = str_replace(strstr( $url, "?xtor"), "", $url );
        $key = md5( $url );

        $txt = addslashes( strip_tags( html_entity_decode( $entry->description ) ) );
        $title = addslashes( strip_tags( html_entity_decode( $entry->title ) ) );
        $nb++;

        $nb_base = mysqli_return_number( $mysqli, "SELECT `id` FROM `base_news` WHERE `key_media`='$key' OR `url` LIKE '$url%' LIMIT 1" );

        if ( trim( $url ) != '' && trim( $title ) != '' && $nb_base == 0 ) {
            mysqli_query( $mysqli, "INSERT INTO `base_news` (`id`, `key_media`, `media`, `url`, `link`, `step`) VALUES (NULL, '$key', '$id_source', '$url', '0', '0');" );
            $id_inserted = $mysqli->insert_id;
            mysqli_query( $mysqli, "UPDATE `base_news` SET `title`='$title' WHERE `id`='$id_inserted' LIMIT 1" );
            mysqli_query( $mysqli, "UPDATE `base_news` SET `txt_clean`='$txt' WHERE `id`='$id_inserted' LIMIT 1" );
        }
    }

    // Second attempt: If no entries were processed in the first attempt, process the top-level entries
    if ( !$nb ) {
        foreach ( $a as $entry ) {
            $url = $entry->loc;
            $url = str_replace( strstr( $url, "#" ), "", $url );
            $url = str_replace(strstr( $url, "?utm"), "", $url );
            $key = md5( $url );
            $nb++;
            $nb_base = mysqli_return_number( $mysqli, "SELECT `id` FROM `base_news` WHERE `key_media`='$key' OR `url` LIKE '$url%' LIMIT 1" );

            if ( trim( $url ) != '' && $nb_base == 0 ) {
                mysqli_query( $mysqli, "INSERT INTO `base_news` (`id`, `key_media`, `media`, `url`, `link`, `step`) VALUES (NULL, '$key', '$id_source', '$url', '0', '0');" );

            }
        }
    }
    
    $nb_base_news =  mysqli_return_number( $mysqli, "SELECT `id` FROM `base_news` WHERE `media` = '$id_source'" ); 
    mysqli_query( $mysqli, "UPDATE `base_media` SET `nb`='$nb_base_news' WHERE `id`='$id_source' LIMIT 1" );
}


// Main script execution
$record = fetchLatestURL( $mysqli );
$id_source = $record['id'];
$url = trim( $record['url'] );
$last_update = $record['last'];

echo "$id_source # $url";

// Exit if the last update is too recent < 1h
if ( $last_update + 3600 > $last ) {
    exit;
}

updateLastFetched( $mysqli, $id_source, $last );
$data = fetchURLContent( $url );
if( trim( $data )!='' ){
    saveToFile( $path . "/sources/rss/" . $id_source . ".txt", $data );
    processRSSContent( $mysqli, $data, $id_source );
}

echo "<script type=\"text/javascript\">location.href='" . $_SERVER ['REQUEST_URI'] . "';</script>";

?>