<?php
/**
 * This source file is part of the open source project
 * ExpressionEngine (https://expressionengine.com)
 *
 * @link      https://expressionengine.com/
 * @copyright Copyright (c) 2003-2022, Packet Tide, LLC (https://www.packettide.com)
 * @license   https://expressionengine.com/license Licensed under Apache License, Version 2.0
 */

/**
 * Core Localization
 */
class Localize
{
    public $now = '';  // Local server time as GMT accounting for server offset
    public $format = array(
        'DATE_ATOM' => '%Y-%m-%dT%H:%i:%s%Q',
        'DATE_COOKIE' => '%l, %d-%M-%y %H:%i:%s UTC',
        'DATE_ISO8601' => '%Y-%m-%dT%H:%i:%s%Q',
        'DATE_RFC822' => '%D, %d %M %y %H:%i:%s %O',
        'DATE_RFC850' => '%l, %d-%M-%y %H:%m:%i UTC',
        'DATE_RFC1036' => '%D, %d %M %y %H:%i:%s %O',
        'DATE_RFC1123' => '%D, %d %M %Y %H:%i:%s %O',
        'DATE_RFC2822' => '%D, %d %M %Y %H:%i:%s %O',
        'DATE_RSS' => '%D, %d %M %Y %H:%i:%s %O',
        'DATE_W3C' => '%Y-%m-%dT%H:%i:%s%Q'
    );

    // Cached timezone and country data, properties not to be accessed directly
    private $_countries = array();
    private $_timezones_by_country = array();

    /**
     * Constructor
     */
    public function __construct()
    {
        // Fetch current Unix timestamp
        $this->now = time();

        // Apply server offset (in minutes) to $now
        if (($offset = ee()->config->item('server_offset'))
            && is_numeric($offset)) {
            $this->now += $offset * 60;
        }
    }

    /**
     * String to Timestamp
     *
     * Converts a human-readable date (and possibly time) to a Unix timestamp
     * using the current member's locale
     *
     * @param	string	$human_string	Human-readable date
     * @param	bool	$localized		Is the human date prelocalized?
     * @param	string	$date_format	(optional) The date format to use when
     *									parsing $human_string
     * @return	mixed	int if successful, otherwise FALSE
     */
    public function string_to_timestamp($human_string, $localized = true, $date_format = null)
    {
        if (trim($human_string) == '') {
            return '';
        }

        $dt = $this->_datetime($human_string, $localized, $date_format);

        // A sanity-check fall back. If we were passed a date format but we
        // failed to parse the date, we'll try again, but without the format.
        // This mimics how we handled date input prior to 2.9.3.
        if ($date_format && ! $dt) {
            $dt = $this->_datetime($human_string, $localized);
        }

        return ($dt) ? $dt->format('U') : false;
    }

    /**
     * Given an EE date format and a Unix timestamp, returns the human-readable
     * date in the specified timezone or member's current timezone.
     *
     * @param	string	Date format, like "%D, %F %d, %Y - %g:%i:%s"
     * @param	int		Unix timestamp
     * @param	bool	Return date localized or not
     * @return	string	Formatted date
     */
    public function format_date($format, $timestamp = null, $localize = true)
    {
        if (! ($dt = $this->_datetime($timestamp, $localize))) {
            return false;
        }

        // Match all EE date vars, which are essentially the normal PHP date
        // vars with a percent sign in front of them
        if (! preg_match_all("/(%\S)/", $format, $matches)) {
            return $dt->format('U');
        }

        // Loop through matched date vars and replace them in the $format string
        foreach ($matches[1] as $var) {
            $format = str_replace($var, $this->_date_string_for_variable($var, $dt), $format);
        }

        return $format;
    }

    /**
     * Given an date variable and a DateTime object, returns the associated
     * formatting for the date variable and DateTime object
     *
     * @param	string		Date variable with percent sign prefix, like "%D"
     * @param	datetime	DateTime object on which to call format()
     * @return	string		Value of variable in DateTime object, translated
     */
    private function _date_string_for_variable($var, $dt)
    {
        // These letters following a percent sign we will convert to their
        // matching PHP date variable value
        $allowed_date_vars = array(
            'a', 'A', 'B', 'c', 'd', 'D', 'e', 'F', 'g', 'G', 'h', 'H', 'i', 'I',
            'j', 'l', 'L', 'm', 'M', 'n', 'N', 'o', 'O', 'P', 'Q', 'r', 's', 'S',
            't', 'T', 'u', 'U', 'w', 'W', 'y', 'Y', 'z', 'Z'
        );

        // These date variables have month or day names and need to be ran
        // through the language library
        $translatable_date_vars = array(
            'a', 'A', 'D', 'F', 'l', 'M', 'r', 'S'
        );

        // If TRUE, the translatable date variables will be run through the
        // language library; this check has been brought over from legacy code
        $translate = ! (isset(ee()->TMPL)
            && is_object(ee()->TMPL)
            && ee()->TMPL->template_type == 'feed');

        // Remove percent sign for easy comparing and passing to DateTime::format
        $date_var = str_replace('%', '', $var);

        if (in_array($date_var, $allowed_date_vars)) {
            // Special cases
            switch ($date_var) {
                // F returns the full month name, but "May" is the same short
                // and long, so we need to catch it and modify the lang key so
                // the correct translation is returned
                case 'F':
                    if ($dt->format('F') == 'May' && $translate) {
                        return lang('May_l');
                    }

                    break;
                // Concatenate the RFC 2822 format with translations
                case 'r':
                    if ($translate) {
                        $rfc = lang($dt->format('D'));		// Thu
                        $rfc .= $dt->format(', d ');						// , 21
                        $rfc .= lang($dt->format('M'));	// Dec
                        $rfc .= $dt->format(' Y H:i:s O'); 					// 2000 16:01:07 +0200

                        return $rfc;
                    }

                    break;
                // Q was our replacement for P because P wasn't available < PHP 5.1.3,
                // so keep it around for backwards compatability
                case 'Q':
                    $date_var = 'P';

                    break;
            }

            // If it's translatable, return the value for the lang key,
            // otherwise send it straight to DateTime::format
            if ($translate && in_array($date_var, $translatable_date_vars)) {
                return lang($dt->format($date_var));
            } else {
                return $dt->format($date_var);
            }
        }

        return $var;
    }

    /**
     * Provides common date format for things like date fields, and takes
     * into consideration the member's time_format preference
     *
     * Example: 2015-10-21 06:30 PM
     *
     * @param	int		Unix timestamp
     * @param	bool	Localize to member's timezone or leave as GMT
     * @param	bool	Include seconds in returned string or not
     * @return	string	Formatted string
     */
    public function human_time($timestamp = null, $localize = true, $seconds = false)
    {
        // Override the userdata/config with the parameter only if it was provided
        $include_seconds = ee()->session->userdata('include_seconds', ee()->config->item('include_seconds'));
        if (func_num_args() != 3 && $include_seconds == 'y') {
            $seconds = true;
        }

        $format_string = $this->get_date_format($seconds);

        return $this->format_date($format_string, $timestamp, $localize);
    }

    /**
     * Provides the date format to use for calculating time (both input and output)
     *
     * @param	bool	Include seconds in the date format string or not
     * @return	string	Date format string
     */
    public function get_date_format($seconds = false)
    {
        $include_seconds = ee()->session->userdata('include_seconds', ee()->config->item('include_seconds'));
        $date_format = ee()->session->userdata('date_format', ee()->config->item('date_format'));
        $time_format = ee()->session->userdata('time_format', ee()->config->item('time_format'));

        // Override the userdata/config with the parameter only if it was provided
        if (func_num_args() != 1 && $include_seconds == 'y') {
            $seconds = true;
        }

        $seconds_format = $seconds ? ':%s' : '';

        $format_string = $date_format . ' ';
        if ($time_format == 24) {
            $format_string .= '%H:%i' . $seconds_format;
        } else {
            $format_string .= '%g:%i' . $seconds_format . ' %A';
        }

        return $format_string;
    }

    /**
     * Returns a DateTime object for the current time and member timezone
     * OR a specified time and timezone
     *
     * @param	string		Date string or Unix timestamp, current time used if NULL
     * @param	mixed		Bool: whether or not to localize to current member's
     *                      timezone, or string of timezone to convert to
     * @return	datetime	DateTime object set to the given time and altered
     * 						for server offset
     */
    private function _datetime($date_string = null, $timezone = true, $date_format = null)
    {
        // Checking for ambiguous dates but only when we don't have a date
        // format.
        if (! $date_format) {
            if (preg_match('/\b\d{1,2}-\d{1,2}-\d{2}\b/', (string) $date_string)) {
                return false;
            }
        }

        // Localize to member's timezone or leave as GMT
        if (is_bool($timezone)) {
            $timezone = ($timezone) ? ee()->session->userdata('timezone', ee()->config->item('default_site_timezone')) : 'UTC';
        }

        // If timezone isn't known by PHP, it may be our legacy timezone
        // notation and needs to be converted
        if (! in_array($timezone, DateTimeZone::listIdentifiers())) {
            $timezone = $this->get_php_timezone($timezone);
        }

        try {
            $timezone = new DateTimeZone($timezone);
            // If $date_string appears to be a Unix timestamp, prepend the
            // string with '@' so DateTime knows it's a timestamp; the
            // timezone parameter is ignored when a timestamp is passed,
            // so set it separately after instantiation
            if (is_numeric($date_string)) {
                $dt = new DateTime('@' . $date_string);
                $dt->setTimezone($timezone);
            }
            // Otherwise, we must instantiate the DateTime object with the
            // correct DateTimeZone so that the date string passed in is
            // immediately interpreted using the member's timezone and not
            // the server timezone; otherwise, using setTimezone to set
            // the timezone later will transform the date
            else {
                // Attempt to use their date (and time) format
                if (! is_null($date_format)) {
                    $date_format = str_replace('%', '', $date_format);
                    $dt = DateTime::createFromFormat($date_format, $date_string, $timezone);

                    // In the case they just passed a date, we need to only use
                    // their date format.
                    if (! $dt) {
                        $date_only_format = ee()->session->userdata(
                            'date_format',
                            ee()->config->item('date_format')
                        );
                        // The pipe makes sure all other time elements are
                        // replaced by the unix epoch
                        $date_only_format = str_replace('%', '', $date_only_format) . '|';
                        $dt = DateTime::createFromFormat(
                            $date_only_format,
                            $date_string,
                            $timezone
                        );
                    }
                }

                // If there's no date format, or if the date format failed, toss
                // it back to PHP.
                // Using `date_create` instead of `new DateTime` to work around
                // a bug in php's usort (https://bugs.php.net/bug.php?id=50688).
                // Used by the table library to sort by date
                if (empty($dt)) {
                    $dt = date_create((string) $date_string, $timezone);

                    if ($dt === false) {
                        return false;
                    }
                }

                $dt = (! empty($dt)) ? $dt : date_create($date_string, $timezone);
            }
        } catch (Exception $e) {
            return false;
        }

        // Apply server offset only
        if (empty($date_string)
            && ($offset = ee()->config->item('server_offset'))
            && is_numeric($offset)) {
            $offset = ($offset > 0) ? '+' . $offset : $offset;
            $dt->modify($offset . ' minutes');
        }

        return $dt;
    }

    /**
     * Generates an HTML menu of timezones
     *
     * @param	string	Default timezone selection
     * @param	string	Name of dropdown form field element
     * @return	string	HTML for dropdown list
     */
    public function timezone_menu($default = null, $name = 'default_site_timezone')
    {
        // For the installer
        ee()->load->helper('language');

        // We only want timezones with these prefixes
        $continents = array('Africa', 'America', 'Antarctica', 'Arctic',
            'Asia', 'Atlantic', 'Australia', 'Europe', 'Indian', 'Pacific');

        $zones_by_country = $this->_get_timezones_by_country();
        $countries = $this->_get_countries();

        $timezones = array();

        foreach ($countries as $code => $country) {
            // If country code does not match any timezones, skip the loop
            if (! isset($zones_by_country[$code])) {
                continue;
            }

            // We'll store timezones for the current country here
            $local_zones = array();

            foreach ($zones_by_country[$code] as $zone) {
                // Explode ID by slashes while replacing underscores with spaces
                $zone_array = str_replace('_', ' ', explode('/', $zone));

                // Exclude deprecated PHP timezones
                if (! in_array($zone_array[0], $continents)) {
                    continue;
                }

                // Construct the localized zone name
                if (isset($zone_array[1])) {
                    $zone_name = lang($zone_array[1]);

                    if (isset($zone_array[2])) {
                        $zone_name .= ' - ' . lang($zone_array[2]);
                    }

                    $local_zones[$zone] = $zone_name;
                }
            }

            // Sort timezones by their new names
            asort($local_zones);

            $timezones[$code] = $local_zones;
        }

        // Convert to JSON for fast switching of timezone dropdown
        $timezone_json = json_encode($timezones);

        $no_timezones_lang = lang('no_timezones');

        // Start the output with some javascript to handle the timezone
        // dropdown population based on the country dropdown
        $output = <<<EOF

			<script type="text/javascript">

				var timezones = $timezone_json

				function ee_tz_change(countryselect)
				{
					var timezoneselect = document.getElementById('timezone_select');
					var countrycode = countryselect.options[countryselect.selectedIndex].value;

					timezoneselect.options.length = 0;

					if (timezones[countrycode] == '' || timezones[countrycode] == undefined)
					{
						timezoneselect.add(new Option('$no_timezones_lang', ''));

						return;
					}

					for (var key in timezones[countrycode])
					{
						if (timezones[countrycode].hasOwnProperty(key))
						{
							timezoneselect.add(new Option(timezones[countrycode][key], key));
						}
					}
				}

			</script>
EOF;

        // Prepend to the top of countries dropdown with common country selections
        $countries = array_merge(
            array(
                lang('select_timezone'),
                '-------------',
                'us' => $countries['us'], // United States
                'gb' => $countries['gb'], // United Kingdom
                'au' => $countries['au'], // Australia
                'ca' => $countries['ca'], // Canada
                'fr' => $countries['fr'], // France
                'ie' => $countries['ie'], // Ireland
                'nz' => $countries['nz'], // New Zealand
                '-------------'
            ),
            $countries
        );

        // Get ready to load preselected values into the dropdowns if one exists
        $selected_country = null;
        $timezone_prepopulated = array('' => lang('no_timezones'));

        if (! empty($default)) {
            $timezone_ids = DateTimeZone::listIdentifiers();

            // If default selection isn't valid, it may be our legacy timezone format
            if (! in_array($default, $timezone_ids)) {
                $default = $this->get_php_timezone($default);
            }

            $selected_country = $this->_get_country_for_php_timezone($default);

            // Preselect timezone if we got a valid country back
            if ($selected_country) {
                $timezone_prepopulated = $timezones[$selected_country];
            }
        }

        // Construct the form
        ee()->load->helper('form');
        $output .= form_dropdown('tz_country', $countries, $selected_country, 'onchange="ee_tz_change(this)"');
        $output .= '&nbsp;&nbsp;'; // NBS constant doesn't work in installer
        $output .= form_dropdown($name, $timezone_prepopulated, $default, 'id="timezone_select"');

        return $output;
    }

    /**
     * Loads countries config file and creates localized array of country
     * codes corresponding to country names
     *
     * @access	private
     * @param	boolean	Whether or not to return timezones mapped to
     *				countries instead
     * @return	string
     */
    private function _get_countries($return_timezones = false)
    {
        if (! empty($this->_countries) and ! $return_timezones) {
            return $this->_countries;
        }

        $conf = ee()->config->loadFile('countries');
        $countries = $conf['countries'];
        $timezones = $conf['timezones'];

        if ($return_timezones) {
            return $timezones;
        }

        foreach ($countries as $code => $country) {
            $countries[$code] = lang($country);
        }

        $this->_countries = $countries;

        return $this->_countries;
    }

    /**
     * Creates and returns a cached array of timezones by country.
     *
     * @access	private
     * @return	array 	Array of timezones by country code
     */
    private function _get_timezones_by_country()
    {
        if (! empty($this->_timezones_by_country)) {
            return $this->_timezones_by_country;
        }

        // PHP 5.3+
        if (defined('DateTimeZone::PER_COUNTRY')) {
            foreach ($this->_get_countries() as $code => $country) {
                $this->_timezones_by_country[$code] = DateTimeZone::listIdentifiers(
                    DateTimeZone::PER_COUNTRY,
                    strtoupper($code)
                );
            }
        }
        // < PHP 5.3
        else {
            $this->_timezones_by_country = $this->_get_countries(true);
        }

        return $this->_timezones_by_country;
    }

    /**
     * Returns the country code for a given PHP timezone
     *
     * @access	private
     * @param	string	PHP timezone
     * @return	string	Two-letter country code for timezone
     */
    private function _get_country_for_php_timezone($timezone)
    {
        foreach ($this->_get_timezones_by_country() as $code => $timezones) {
            if (in_array($timezone, $timezones)) {
                return $code;
            }
        }

        return false;
    }

    /**
     * Gets the PHP timezone for the legacy timezone format EE used to
     * store timezones with which was based on offsets; for example, given
     * "UM5", it returns "America/New_York"
     *
     * @access	public
     * @param	string
     * @return	string
     */
    public function get_php_timezone($zone = 'UTC')
    {
        $zones = array(
            'UM12' => 'Kwajalein', 					// -12
            'UM11' => 'Pacific/Midway', 				// -11
            'UM10' => 'Pacific/Honolulu', 				// -10
            'UM95' => 'Pacific/Marquesas',				// -9.5
            'UM9' => 'America/Anchorage', 			// -9
            'UM8' => 'America/Los_Angeles', 			// -8
            'UM7' => 'America/Denver', 				// -7
            'UM6' => 'America/Chicago', 				// -6
            'UM5' => 'America/New_York', 				// -5
            'UM45' => 'America/Caracas',				// -4.5
            'UM4' => 'America/Halifax', 				// -4
            'UM35' => 'America/St_Johns', 				// -3.5
            'UM3' => 'America/Argentina/Buenos_Aires',// -3
            'UM2' => 'Atlantic/South_Georgia', 		// -2
            'UM1' => 'Atlantic/Azores', 				// -1
            'UTC' => 'Europe/Dublin', 				// 0
            'UP1' => 'Europe/Belgrade', 				// +1
            'UP2' => 'Europe/Minsk', 					// +2
            'UP3' => 'Asia/Kuwait', 					// +3
            'UP35' => 'Asia/Tehran', 					// +3.5
            'UP4' => 'Asia/Muscat', 					// +4
            'UP45' => 'Asia/Kabul', 					// +4.5
            'UP5' => 'Asia/Yekaterinburg', 			// +5
            'UP55' => 'Asia/Kolkata',		 			// +5.5
            'UP575' => 'Asia/Katmandu', 				// +5.75
            'UP6' => 'Asia/Dhaka', 					// +6
            'UP65' => 'Asia/Rangoon', 					// +6.5
            'UP7' => 'Asia/Krasnoyarsk', 				// +7
            'UP8' => 'Asia/Brunei', 					// 8
            'UP875' => 'Australia/Eucla',				// +8.75
            'UP9' => 'Asia/Seoul', 					// +9
            'UP95' => 'Australia/Darwin', 				// +9.5
            'UP10' => 'Australia/Canberra', 			// +10
            'UP105' => 'Australia/Lord_Howe',			// +10.5
            'UP11' => 'Asia/Magadan', 					// +11
            'UP115' => 'Pacific/Norfolk',				// +11.5
            'UP12' => 'Pacific/Fiji', 					// +12
            'UP1275' => 'Pacific/Chatham',				// +12.75
            'UP13' => 'Pacific/Tongatapu', 			// +13
            'UP14' => 'Pacific/Kiritimati'				// +14
        );

        // Fall back to UTC if something went wrong
        if (! isset($zones[$zone])) {
            return 'UTC';
        }

        return $zones[$zone];
    }

    /**
     * Localize month name
     *
     * Helper function used to translate month names.
     *
     * @access	public
     * @param	string
     * @return	string
     */
    public function localize_month($month = '')
    {
        $months = array(
            '01' => array('Jan', 'January'),
            '02' => array('Feb', 'February'),
            '03' => array('Mar', 'March'),
            '04' => array('Apr', 'April'),
            '05' => array('May', 'May_l'),
            '06' => array('Jun', 'June'),
            '07' => array('Jul', 'July'),
            '08' => array('Aug', 'August'),
            '09' => array('Sep', 'September'),
            '10' => array('Oct', 'October'),
            '11' => array('Nov', 'November'),
            '12' => array('Dec', 'December')
        );

        if (isset($months[$month])) {
            return $months[$month];
        }
    }

    /**
     * Reads the configured date format from either userdata or the site's
     * config and returns the string needed to format the JS datepicker
     * to match.
     *
     * @access public
     * @return string The string needed for the 'dateFormat:' argument for
     *                the jQuery datepicker plugin.
     */
    public function datepicker_format()
    {
        $date_format = ee()->session->userdata('date_format', ee()->config->item('date_format'));

        // Days
        $date_format = str_replace('%d', 'dd', $date_format);
        $date_format = str_replace('%j', 'd', $date_format);

        // Months
        $date_format = str_replace('%m', 'mm', $date_format);
        $date_format = str_replace('%n', 'm', $date_format);

        // Years
        $date_format = str_replace('%Y', 'yy', $date_format);
        $date_format = str_replace('%y', 'y', $date_format);

        return $date_format;
    }

    /**
     * Converts our build date constant into a timestamp so we can format it
     * for display
     *
     * @param  string Build date in the format of yyyymmdd, uses APP_BUILD by default
     * @return int Timestamp representing the build date
     */
    public function parse_build_date($build = null)
    {
        if (empty($build)) {
            $build = APP_BUILD;
        }

        $year = substr($build, 0, 4);
        $month = substr($build, 4, 2);
        $day = substr($build, 6, 2);

        $string = $year . '-' . $month . '-' . $day;

        return ee()->localize->string_to_timestamp($string, true, '%Y-%m-%d');
    }
}
// END CLASS

// EOF
