<?php

    $IMG_SIZE_PREVIEW = 600;
    $IMG_SIZE_MINIATURE = 200;
    
    
    function getProtocol(){
        if (isset($_SERVER['HTTPS']) && ($_SERVER['HTTPS'] == 'on' || $_SERVER['HTTPS'] == 1) || isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https') {
                $protocol = 'https://';
        }
        else {
                $protocol = 'http://';
        }
        return $protocol;
    }


    /****************************************************
    * This function is called from almost everywhere at *
    * the beggining of the page. It initializes the     *
    * session variables, connect to the db, enabling    *
    * the variable $con for futher use everywhere in    *
    * the php code, and populates the arrays $user      *
    * and $permission, with info about the user.        *
    * @params:                                          *
    *    mode: (string) Indicates required permissions  *
    *          on database. 'ro' gives read             *
    *          permissions, and 'rw' read and write     *
    *          permissions. Other values will result in *
    *          errors.                                  *
    * @return: (db connection): The connection handler. *
    ****************************************************/
    function startdb($mode = 'ro'){
        //Include the db configuration file. It's somehow like this
        /*
        <?php
            $host = 'XXXX';
            $db_name = 'XXXX';
            $username_ro = 'XXXX';
            $username_rw = 'XXXX';
            $pass_ro = 'XXXX';
            $pass_rw = 'XXXX';
        ?>
        */
        include('.htpasswd');
        
        //Connect to to database
        if ($mode == 'ro')
            $con = mysqli_connect($host, $username_ro, $pass_ro, $db_name);
        else if ($mode == 'rw')
            $con = mysqli_connect($host, $username_rw, $pass_rw, $db_name);
            
        // Check connection
        if (mysqli_connect_errno()){
            error_log("Failed to connect to database: " . mysqli_connect_error());
            return -1;
        }
        
        //Set encoding options
        mysqli_set_charset($con, 'utf-8');
        header('Content-Type: text/html; charset=utf8');
        mysqli_query($con, 'SET NAMES utf8;');
        
        //Return the db connection
        return $con;
    }
    
    
    /****************************************************
    * This function turns a date string into a human    *
    * readable string, deppending o the specified       * 
    * language.                                         *
    * @params:                                          *
    *    strdate: (string): Date string.                *
    *    lang: (string): Language code (es, en, eu).    *
    *    http_accept_language: (string) Raw header with *
    *                          info about client        *
    *                          language preferences.    *
    *    time: (boolean): Append the time at the end.   *
    * @return: (string array) List of the languages     *
    *          offered, sorted by prefference.          *
    ****************************************************/    
    function formatDate($strdate, $lang, $time = true){
        $date = strtotime($strdate);
        $year = date('o', $date);
        $month = date('n', $date);
        $month --;
        $day = date('j', $date);
        $wday = date('N', $date);
        $wday --;
        $hour = date('H', $date);
        $minute = date('i', $date);
        switch ($lang){
            case 'en':
                $week = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];
                $months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
                if ($time){
                    $str = "$week[$wday], $months[$month] $day, $year at $hour:$minute";
                }
                else{
                    $str = "$week[$wday], $months[$month] $day, $year";
                }
                break;
            case 'eu':
                $week = ['astelehena', 'asteartea', 'asteazkena', 'osteguna', 'ostirala', 'larumbata', 'igandea'];
                $months = ['urtarrilaren', 'otsailaren', 'martxoaren', 'apirilaren', 'maiatzaren', 'ekainaren', 'uztailaren', 'abuztuaren', 'irailaren', 'urriaren', 'azaroaren', 'abenduaren'];
                if ($time){
                    $str = $year . "ko $months[$month] $day" . "an, $week[$wday], $hour:$minute";
                }
                else{
                    $str = $year . "ko $months[$month] $day" . "an, $week[$wday]";
                }
                break;
            default:
                $week = ['Lunes', 'Martes', 'Mi&eacute;rcoles', 'Jueves', 'Viernes', 'S&aacute;bado', 'Domingo'];
                $months = ['enero', ' febrero', 'marzo', 'abril', 'mayo', 'junio', 'julio', 'agosto', 'septiembre', 'octubre', 'noviembre', 'diciembre'];
                if ($time){
                    $str = "$week[$wday] $day de $months[$month] de $year a las $hour:$minute";
                }
                else{
                    $str = "$week[$wday] $day de $months[$month] de $year";
                }
        }
        return $str;
    }
    
    /****************************************************
    * This function turns a date string into a human    *
    * readable string, deppending o the specified       * 
    * language. It is designed to be used for festival  *
    * days only, since it doesnt return the weekday.    *
    * @params:                                          *
    *    strdate: (string): Date string.                *
    *    lang: (string): Language code (es, en, eu).    *
    *    http_accept_language: (string) Raw header with *
    *                          info about client        *
    *                          language preferences.    *
    * @return: (string array) List of the languages     *
    *          offered, sorted by prefference.          *
    ****************************************************/    
    function formatFestivalDate($strdate, $lang){
        $date = strtotime($strdate);
        $month = date('n', $date);
        $month --;
        $day = date('j', $date);
        switch ($lang){
            case 'en':
                $months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
                $str = "$months[$month] $day";
                break;
            case 'eu':
                $months = ['urtarrilaren', 'otsailaren', 'martxoaren', 'apirilaren', 'maiatzaren', 'ekainaren', 'uztailaren', 'abuztuaren', 'irailaren', 'urriaren', 'azaroaren', 'abenduaren'];
                $str = "$months[$month] $day";
                break;
            default:
                $months = ['enero', ' febrero', 'marzo', 'abril', 'mayo', 'junio', 'julio', 'agosto', 'septiembre', 'octubre', 'noviembre', 'diciembre'];
                $str = "$day de $months[$month]";
        }
        return $str;
    }
    
    /****************************************************
    * This function closes all the opened HTML tags in  *
    * a given string.                                   * 
    *                                                   *
    * @params:                                          *
    *    html: (string): The string with HTML tags      *
     ****************************************************/
    function closeTags($html) {
        preg_match_all('#<(?!meta|img|br|hr|input\b)\b([a-z]+)(?: .*)?(?<![/|/ ])>#iU', $html, $result);
        $openedtags = $result[1];
        preg_match_all('#</([a-z]+)>#iU', $html, $result);
        $closedtags = $result[1];
        $len_opened = count($openedtags);
        if (count($closedtags) == $len_opened) {
            return $html;
        }
        $openedtags = array_reverse($openedtags);
        for ($i=0; $i < $len_opened; $i++) {
            if (!in_array($openedtags[$i], $closedtags)) {
                $html .= '</'.$openedtags[$i].'>';
            } else {
                unset($closedtags[array_search($openedtags[$i], $closedtags)]);
            }
        }
        return $html;
    } 
    
    /****************************************************
    * Text shortener. Given a string, it trims in the   *
    * proximity of the desired streng, ut to the next   * 
    * white character. If indicated, it will append a   *
    * link to the full text.                            *
    *                                                   *
    * @params:                                          *
    *    text: (string): The text to shorten.           *
    *    length: (int): The desired length.             *
    *    linktext: (string): Text fot the link.         *
    *    link: (string): URI of the full text.          *
     ****************************************************/
     function cutText($text, $length, $linktext, $link){
        if (strlen($text) < $length){
            return $text;
        }
        $cut = substr($text, 0, strpos($text, " ", $length));
        $cut = closeTags($cut);
        if (strlen($cut) == 0){
            $cut = $text;
        }
        if (strlen($text) != strlen($cut)){
            $cut = $cut . "... <a href='$link'>$linktext</a>";
        }
        return $cut;
    }
    
    /****************************************************
    * Generates a URL-valid string from a regular one.  *
    *                                                   *
    * @params:                                          *
    *    text: (string): Original string.               *
    * @return: (string): URL-valid string.              *
    ****************************************************/
    function permalink($text){
        $unwanted_array = array('Š'=>'S', 'š'=>'s', 'Ž'=>'Z', 'ž'=>'z', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'A', 'Å'=>'A', 'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E',
                            'Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U',
                            'Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a', 'æ'=>'a', 'ç'=>'c',
                            'è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i', 'ï'=>'i', 'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o',
                            'ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 'û'=>'u', 'ý'=>'y', 'þ'=>'b', 'ÿ'=>'y' );
        $str = strtr( $text, $unwanted_array );
        $str = preg_replace('/[^\da-zA-Z ]/i', '', $str);
        $str = str_replace(' ', '-', $str);
        return $str;
    }
    
    function login($con, $user, $pass){
        session_start();
        $q = mysqli_query($con,"SELECT id, salt, username AS username, sha1(salt) AS s FROM user WHERE (lower(username) = lower('$user') OR lower(email) = lower('$user')) AND password = sha1(concat('$pass', sha1(salt)));");
        if (mysqli_num_rows($q) == 1){
            $r = mysqli_fetch_array($q);
            $_SESSION['id'] = $r['id'];
            $_SESSION['salt'] = $r['s'];
            $_SESSION['name'] = $r['username'];
            return true;
        }
        else{
            error_log("Invalid login. username = $_SESSION[name], id = $_SESSION[id]");
            return false;
        }
    }
    
    function checkSession($con){
        session_start(['cookie_lifetime' => 1800,]);
        $qr = mysqli_query($con, "SELECT id FROM user WHERE id = '$_SESSION[id]' AND sha1(salt) = '$_SESSION[salt]';");
        //error_log("SELECT id FROM user WHERE id = '$_SESSION[id]' AND md5(salt) = '$_SESSION[salt]';");
        if (mysqli_num_rows($qr) == 1)
            return true;
        else{
            return false;
            error_log("Invalid session. username = $_SESSION[name], id = $_SESSION[id]");
        }
    }
    

    /****************************************************
    * Increases version value in table settings by one. *
    * Helpfull for the app to know when to perform a    * 
    * full sync. Must be called after every INSERT,     *
    * UPDATE or DELETE query to the database.           *
     ****************************************************/
    function version(){
        $con = startdb('rw');
        mysqli_query($con, 'UPDATE settings SET value = value + 1 WHERE name = "version";');
    }
?>