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[mediawiki.git] / includes / MWTimestamp.php

<?php
/**
 * Creation and parsing of MW-style timestamps.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @since 1.20
 * @author Tyler Romeo, 2012
 */

/**
 * Library for creating and parsing MW-style timestamps. Based on the JS
 * library that does the same thing.
 *
 * @since 1.20
 */
class MWTimestamp {
        /**
         * Standard gmdate() formats for the different timestamp types.
         */
        private static $formats = [
                TS_UNIX => 'U',
                TS_MW => 'YmdHis',
                TS_DB => 'Y-m-d H:i:s',
                TS_ISO_8601 => 'Y-m-d\TH:i:s\Z',
                TS_ISO_8601_BASIC => 'Ymd\THis\Z',
                TS_EXIF => 'Y:m:d H:i:s', // This shouldn't ever be used, but is included for completeness
                TS_RFC2822 => 'D, d M Y H:i:s',
                TS_ORACLE => 'd-m-Y H:i:s.000000', // Was 'd-M-y h.i.s A' . ' +00:00' before r51500
                TS_POSTGRES => 'Y-m-d H:i:s',
        ];

        /**
         * The actual timestamp being wrapped (DateTime object).
         * @var DateTime
         */
        public $timestamp;

        /**
         * Make a new timestamp and set it to the specified time,
         * or the current time if unspecified.
         *
         * @since 1.20
         *
         * @param bool|string|int|float $timestamp Timestamp to set, or false for current time
         */
        public function __construct( $timestamp = false ) {
                $this->setTimestamp( $timestamp );
        }

        /**
         * Set the timestamp to the specified time, or the current time if unspecified.
         *
         * Parse the given timestamp into either a DateTime object or a Unix timestamp,
         * and then store it.
         *
         * @since 1.20
         *
         * @param string|bool $ts Timestamp to store, or false for now
         * @throws TimestampException
         */
        public function setTimestamp( $ts = false ) {
                $m = [];
                $da = [];
                $strtime = '';

                // We want to catch 0, '', null... but not date strings starting with a letter.
                if ( !$ts || $ts === "\0\0\0\0\0\0\0\0\0\0\0\0\0\0" ) {
                        $uts = time();
                        $strtime = "@$uts";
                } elseif ( preg_match( '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
                        # TS_DB
                } elseif ( preg_match( '/^(\d{4}):(\d\d):(\d\d) (\d\d):(\d\d):(\d\d)$/D', $ts, $da ) ) {
                        # TS_EXIF
                } elseif ( preg_match( '/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)$/D', $ts, $da ) ) {
                        # TS_MW
                } elseif ( preg_match( '/^(-?\d{1,13})(\.\d+)?$/D', $ts, $m ) ) {
                        # TS_UNIX
                        $strtime = "@{$m[1]}"; // http://php.net/manual/en/datetime.formats.compound.php
                } elseif ( preg_match( '/^\d{2}-\d{2}-\d{4} \d{2}:\d{2}:\d{2}.\d{6}$/', $ts ) ) {
                        # TS_ORACLE // session altered to DD-MM-YYYY HH24:MI:SS.FF6
                        $strtime = preg_replace( '/(\d\d)\.(\d\d)\.(\d\d)(\.(\d+))?/', "$1:$2:$3",
                                        str_replace( '+00:00', 'UTC', $ts ) );
                } elseif ( preg_match(
                        '/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.*\d*)?Z?$/',
                        $ts,
                        $da
                ) ) {
                        # TS_ISO_8601
                } elseif ( preg_match(
                        '/^(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})(?:\.*\d*)?Z?$/',
                        $ts,
                        $da
                ) ) {
                        # TS_ISO_8601_BASIC
                } elseif ( preg_match(
                        '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d*[\+\- ](\d\d)$/',
                        $ts,
                        $da
                ) ) {
                        # TS_POSTGRES
                } elseif ( preg_match(
                        '/^(\d{4})\-(\d\d)\-(\d\d) (\d\d):(\d\d):(\d\d)\.*\d* GMT$/',
                        $ts,
                        $da
                ) ) {
                        # TS_POSTGRES
                } elseif ( preg_match(
                        # Day of week
                        '/^[ \t\r\n]*([A-Z][a-z]{2},[ \t\r\n]*)?' .
                        # dd Mon yyyy
                        '\d\d?[ \t\r\n]*[A-Z][a-z]{2}[ \t\r\n]*\d{2}(?:\d{2})?' .
                        # hh:mm:ss
                        '[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d[ \t\r\n]*:[ \t\r\n]*\d\d/S',
                        $ts
                ) ) {
                        # TS_RFC2822, accepting a trailing comment.
                        # See http://www.squid-cache.org/mail-archive/squid-users/200307/0122.html / r77171
                        # The regex is a superset of rfc2822 for readability
                        $strtime = strtok( $ts, ';' );
                } elseif ( preg_match( '/^[A-Z][a-z]{5,8}, \d\d-[A-Z][a-z]{2}-\d{2} \d\d:\d\d:\d\d/', $ts ) ) {
                        # TS_RFC850
                        $strtime = $ts;
                } elseif ( preg_match( '/^[A-Z][a-z]{2} [A-Z][a-z]{2} +\d{1,2} \d\d:\d\d:\d\d \d{4}/', $ts ) ) {
                        # asctime
                        $strtime = $ts;
                } else {
                        throw new TimestampException( __METHOD__ . ": Invalid timestamp - $ts" );
                }

                if ( !$strtime ) {
                        $da = array_map( 'intval', $da );
                        $da[0] = "%04d-%02d-%02dT%02d:%02d:%02d.00+00:00";
                        $strtime = call_user_func_array( "sprintf", $da );
                }

                try {
                        $final = new DateTime( $strtime, new DateTimeZone( 'GMT' ) );
                } catch ( Exception $e ) {
                        throw new TimestampException( __METHOD__ . ': Invalid timestamp format.', $e->getCode(), $e );
                }

                if ( $final === false ) {
                        throw new TimestampException( __METHOD__ . ': Invalid timestamp format.' );
                }
                $this->timestamp = $final;
        }

        /**
         * Get the timestamp represented by this object in a certain form.
         *
         * Convert the internal timestamp to the specified format and then
         * return it.
         *
         * @since 1.20
         *
         * @param int $style Constant Output format for timestamp
         * @throws TimestampException
         * @return string The formatted timestamp
         */
        public function getTimestamp( $style = TS_UNIX ) {
                if ( !isset( self::$formats[$style] ) ) {
                        throw new TimestampException( __METHOD__ . ': Illegal timestamp output type.' );
                }

                $output = $this->timestamp->format( self::$formats[$style] );

                if ( ( $style == TS_RFC2822 ) || ( $style == TS_POSTGRES ) ) {
                        $output .= ' GMT';
                }

                if ( $style == TS_MW && strlen( $output ) !== 14 ) {
                        throw new TimestampException( __METHOD__ . ': The timestamp cannot be represented in ' .
                                'the specified format' );
                }

                return $output;
        }

        /**
         * Get the timestamp in a human-friendly relative format, e.g., "3 days ago".
         *
         * Determine the difference between the timestamp and the current time, and
         * generate a readable timestamp by returning "<N> <units> ago", where the
         * largest possible unit is used.
         *
         * @since 1.20
         * @since 1.22 Uses Language::getHumanTimestamp to produce the timestamp
         * @deprecated since 1.26 Use Language::getHumanTimestamp directly
         *
         * @param MWTimestamp|null $relativeTo The base timestamp to compare to (defaults to now)
         * @param User|null $user User the timestamp is being generated for
         *  (or null to use main context's user)
         * @param Language|null $lang Language to use to make the human timestamp
         *  (or null to use main context's language)
         * @return string Formatted timestamp
         */
        public function getHumanTimestamp(
                MWTimestamp $relativeTo = null, User $user = null, Language $lang = null
        ) {
                if ( $lang === null ) {
                        $lang = RequestContext::getMain()->getLanguage();
                }

                return $lang->getHumanTimestamp( $this, $relativeTo, $user );
        }

        /**
         * Adjust the timestamp depending on the given user's preferences.
         *
         * @since 1.22
         *
         * @param User $user User to take preferences from
         * @return DateInterval Offset that was applied to the timestamp
         */
        public function offsetForUser( User $user ) {
                global $wgLocalTZoffset;

                $option = $user->getOption( 'timecorrection' );
                $data = explode( '|', $option, 3 );

                // First handle the case of an actual timezone being specified.
                if ( $data[0] == 'ZoneInfo' ) {
                        try {
                                $tz = new DateTimeZone( $data[2] );
                        } catch ( Exception $e ) {
                                $tz = false;
                        }

                        if ( $tz ) {
                                $this->timestamp->setTimezone( $tz );
                                return new DateInterval( 'P0Y' );
                        } else {
                                $data[0] = 'Offset';
                        }
                }

                $diff = 0;
                // If $option is in fact a pipe-separated value, check the
                // first value.
                if ( $data[0] == 'System' ) {
                        // First value is System, so use the system offset.
                        if ( $wgLocalTZoffset !== null ) {
                                $diff = $wgLocalTZoffset;
                        }
                } elseif ( $data[0] == 'Offset' ) {
                        // First value is Offset, so use the specified offset
                        $diff = (int)$data[1];
                } else {
                        // $option actually isn't a pipe separated value, but instead
                        // a comma separated value. Isn't MediaWiki fun?
                        $data = explode( ':', $option );
                        if ( count( $data ) >= 2 ) {
                                // Combination hours and minutes.
                                $diff = abs( (int)$data[0] ) * 60 + (int)$data[1];
                                if ( (int)$data[0] < 0 ) {
                                        $diff *= -1;
                                }
                        } else {
                                // Just hours.
                                $diff = (int)$data[0] * 60;
                        }
                }

                $interval = new DateInterval( 'PT' . abs( $diff ) . 'M' );
                if ( $diff < 1 ) {
                        $interval->invert = 1;
                }

                $this->timestamp->add( $interval );
                return $interval;
        }

        /**
         * Generate a purely relative timestamp, i.e., represent the time elapsed between
         * the given base timestamp and this object.
         *
         * @param MWTimestamp $relativeTo Relative base timestamp (defaults to now)
         * @param User $user Use to use offset for
         * @param Language $lang Language to use
         * @param array $chosenIntervals Intervals to use to represent it
         * @return string Relative timestamp
         */
        public function getRelativeTimestamp(
                MWTimestamp $relativeTo = null,
                User $user = null,
                Language $lang = null,
                array $chosenIntervals = []
        ) {
                if ( $relativeTo === null ) {
                        $relativeTo = new self;
                }
                if ( $user === null ) {
                        $user = RequestContext::getMain()->getUser();
                }
                if ( $lang === null ) {
                        $lang = RequestContext::getMain()->getLanguage();
                }

                $ts = '';
                $diff = $this->diff( $relativeTo );
                if ( Hooks::run(
                        'GetRelativeTimestamp',
                        [ &$ts, &$diff, $this, $relativeTo, $user, $lang ]
                ) ) {
                        $seconds = ( ( ( $diff->days * 24 + $diff->h ) * 60 + $diff->i ) * 60 + $diff->s );
                        $ts = wfMessage( 'ago', $lang->formatDuration( $seconds, $chosenIntervals ) )
                                ->inLanguage( $lang )->text();
                }

                return $ts;
        }

        /**
         * @since 1.20
         *
         * @return string
         */
        public function __toString() {
                return $this->getTimestamp();
        }

        /**
         * Calculate the difference between two MWTimestamp objects.
         *
         * @since 1.22
         * @param MWTimestamp $relativeTo Base time to calculate difference from
         * @return DateInterval|bool The DateInterval object representing the
         *   difference between the two dates or false on failure
         */
        public function diff( MWTimestamp $relativeTo ) {
                return $this->timestamp->diff( $relativeTo->timestamp );
        }

        /**
         * Set the timezone of this timestamp to the specified timezone.
         *
         * @since 1.22
         * @param string $timezone Timezone to set
         * @throws TimestampException
         */
        public function setTimezone( $timezone ) {
                try {
                        $this->timestamp->setTimezone( new DateTimeZone( $timezone ) );
                } catch ( Exception $e ) {
                        throw new TimestampException( __METHOD__ . ': Invalid timezone.', $e->getCode(), $e );
                }
        }

        /**
         * Get the timezone of this timestamp.
         *
         * @since 1.22
         * @return DateTimeZone The timezone
         */
        public function getTimezone() {
                return $this->timestamp->getTimezone();
        }

        /**
         * Get the localized timezone message, if available.
         *
         * Premade translations are not shipped as format() may return whatever the
         * system uses, localized or not, so translation must be done through wiki.
         *
         * @since 1.27
         * @return Message The localized timezone message
         */
        public function getTimezoneMessage() {
                $tzMsg = $this->format( 'T' );  // might vary on DST changeover!
                $key = 'timezone-' . strtolower( trim( $tzMsg ) );
                $msg = wfMessage( $key );
                if ( $msg->exists() ) {
                        return $msg;
                } else {
                        return new RawMessage( $tzMsg );
                }
        }

        /**
         * Format the timestamp in a given format.
         *
         * @since 1.22
         * @param string $format Pattern to format in
         * @return string The formatted timestamp
         */
        public function format( $format ) {
                return $this->timestamp->format( $format );
        }

        /**
         * Get a timestamp instance in the server local timezone ($wgLocaltimezone)
         *
         * @since 1.22
         * @param bool|string $ts Timestamp to set, or false for current time
         * @return MWTimestamp The local instance
         */
        public static function getLocalInstance( $ts = false ) {
                global $wgLocaltimezone;
                $timestamp = new self( $ts );
                $timestamp->setTimezone( $wgLocaltimezone );
                return $timestamp;
        }

        /**
         * Get a timestamp instance in GMT
         *
         * @since 1.22
         * @param bool|string $ts Timestamp to set, or false for current time
         * @return MWTimestamp The instance
         */
        public static function getInstance( $ts = false ) {
                return new self( $ts );
        }
}