<?php
/**
 * @author Joas Schilling <coding@schilljs.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC;

class DateTimeFormatter implements \OCP\IDateTimeFormatter {
	/** @var \DateTimeZone */
	protected $defaultTimeZone;

	/** @var \OCP\IL10N */
	protected $defaultL10N;

	/**
	 * Constructor
	 *
	 * @param \DateTimeZone $defaultTimeZone Set the timezone for the format
	 * @param \OCP\IL10N $defaultL10N Set the language for the format
	 */
	public function __construct(\DateTimeZone $defaultTimeZone, \OCP\IL10N $defaultL10N) {
		$this->defaultTimeZone = $defaultTimeZone;
		$this->defaultL10N = $defaultL10N;
	}

	/**
	 * Get TimeZone to use
	 *
	 * @param \DateTimeZone $timeZone	The timezone to use
	 * @return \DateTimeZone		The timezone to use, falling back to the current user's timezone
	 */
	protected function getTimeZone($timeZone = null) {
		if ($timeZone === null) {
			$timeZone = $this->defaultTimeZone;
		}

		return $timeZone;
	}

	/**
	 * Get \OCP\IL10N to use
	 *
	 * @param \OCP\IL10N $l	The locale to use
	 * @return \OCP\IL10N		The locale to use, falling back to the current user's locale
	 */
	protected function getLocale($l = null) {
		if ($l === null) {
			$l = $this->defaultL10N;
		}

		return $l;
	}

	/**
	 * Generates a DateTime object with the given timestamp and TimeZone
	 *
	 * @param mixed $timestamp
	 * @param \DateTimeZone $timeZone	The timezone to use
	 * @return \DateTime
	 */
	protected function getDateTime($timestamp, \DateTimeZone $timeZone = null) {
		if ($timestamp === null) {
			return new \DateTime('now', $timeZone);
		} else if (!$timestamp instanceof \DateTime) {
			$dateTime = new \DateTime('now', $timeZone);
			$dateTime->setTimestamp($timestamp);
			return $dateTime;
		}
		if ($timeZone) {
			$timestamp->setTimezone($timeZone);
		}
		return $timestamp;
	}

	/**
	 * Formats the date of the given timestamp
	 *
	 * @param int|\DateTime	$timestamp	Either a Unix timestamp or DateTime object
	 * @param string	$format			Either 'full', 'long', 'medium' or 'short'
	 * 				full:	e.g. 'EEEE, MMMM d, y'	=> 'Wednesday, August 20, 2014'
	 * 				long:	e.g. 'MMMM d, y'		=> 'August 20, 2014'
	 * 				medium:	e.g. 'MMM d, y'			=> 'Aug 20, 2014'
	 * 				short:	e.g. 'M/d/yy'			=> '8/20/14'
	 * 				The exact format is dependent on the language
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted date string
	 */
	public function formatDate($timestamp, $format = 'long', \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		return $this->format($timestamp, 'date', $format, $timeZone, $l);
	}

	/**
	 * Formats the date of the given timestamp
	 *
	 * @param int|\DateTime	$timestamp	Either a Unix timestamp or DateTime object
	 * @param string	$format			Either 'full', 'long', 'medium' or 'short'
	 * 				full:	e.g. 'EEEE, MMMM d, y'	=> 'Wednesday, August 20, 2014'
	 * 				long:	e.g. 'MMMM d, y'		=> 'August 20, 2014'
	 * 				medium:	e.g. 'MMM d, y'			=> 'Aug 20, 2014'
	 * 				short:	e.g. 'M/d/yy'			=> '8/20/14'
	 * 				The exact format is dependent on the language
	 * 					Uses 'Today', 'Yesterday' and 'Tomorrow' when applicable
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted relative date string
	 */
	public function formatDateRelativeDay($timestamp, $format = 'long', \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		if (substr($format, -1) !== '*' && substr($format, -1) !== '*') {
			$format .= '^';
		}

		return $this->format($timestamp, 'date', $format, $timeZone, $l);
	}

	/**
	 * Gives the relative date of the timestamp
	 * Only works for past dates
	 *
	 * @param int|\DateTime	$timestamp	Either a Unix timestamp or DateTime object
	 * @param int|\DateTime	$baseTimestamp	Timestamp to compare $timestamp against, defaults to current time
	 * @return string	Dates returned are:
	 * 				<  1 month	=> Today, Yesterday, n days ago
	 * 				< 13 month	=> last month, n months ago
	 * 				>= 13 month	=> last year, n years ago
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted date span
	 */
	public function formatDateSpan($timestamp, $baseTimestamp = null, \OCP\IL10N $l = null) {
		$l = $this->getLocale($l);
		$timestamp = $this->getDateTime($timestamp);
		$timestamp->setTime(0, 0, 0);
		if ($baseTimestamp === null) {
			$baseTimestamp = time();
		}
		$baseTimestamp = $this->getDateTime($baseTimestamp);
		$baseTimestamp->setTime(0, 0, 0);
		$dateInterval = $timestamp->diff($baseTimestamp);

		if ($dateInterval->y == 0 && $dateInterval->m == 0 && $dateInterval->d == 0) {
			return (string) $l->t('today');
		} else if ($dateInterval->y == 0 && $dateInterval->m == 0 && $dateInterval->d == 1) {
			return (string) $l->t('yesterday');
		} else if ($dateInterval->y == 0 && $dateInterval->m == 0) {
			return (string) $l->n('%n day ago', '%n days ago', $dateInterval->d);
		} else if ($dateInterval->y == 0 && $dateInterval->m == 1) {
			return (string) $l->t('last month');
		} else if ($dateInterval->y == 0) {
			return (string) $l->n('%n month ago', '%n months ago', $dateInterval->m);
		} else if ($dateInterval->y == 1) {
			return (string) $l->t('last year');
		}
		return (string) $l->n('%n year ago', '%n years ago', $dateInterval->y);
	}

	/**
	 * Formats the time of the given timestamp
	 *
	 * @param int|\DateTime	$timestamp	Either a Unix timestamp or DateTime object
	 * @param string	$format			Either 'full', 'long', 'medium' or 'short'
	 * 				full:	e.g. 'h:mm:ss a zzzz'	=> '11:42:13 AM GMT+0:00'
	 * 				long:	e.g. 'h:mm:ss a z'		=> '11:42:13 AM GMT'
	 * 				medium:	e.g. 'h:mm:ss a'		=> '11:42:13 AM'
	 * 				short:	e.g. 'h:mm a'			=> '11:42 AM'
	 * 				The exact format is dependent on the language
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted time string
	 */
	public function formatTime($timestamp, $format = 'medium', \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		return $this->format($timestamp, 'time', $format, $timeZone, $l);
	}

	/**
	 * Gives the relative past time of the timestamp
	 *
	 * @param int|\DateTime	$timestamp	Either a Unix timestamp or DateTime object
	 * @param int|\DateTime	$baseTimestamp	Timestamp to compare $timestamp against, defaults to current time
	 * @return string	Dates returned are:
	 * 				< 60 sec	=> seconds ago
	 * 				<  1 hour	=> n minutes ago
	 * 				<  1 day	=> n hours ago
	 * 				<  1 month	=> Yesterday, n days ago
	 * 				< 13 month	=> last month, n months ago
	 * 				>= 13 month	=> last year, n years ago
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted time span
	 */
	public function formatTimeSpan($timestamp, $baseTimestamp = null, \OCP\IL10N $l = null) {
		$l = $this->getLocale($l);
		$timestamp = $this->getDateTime($timestamp);
		if ($baseTimestamp === null) {
			$baseTimestamp = time();
		}
		$baseTimestamp = $this->getDateTime($baseTimestamp);

		$diff = $timestamp->diff($baseTimestamp);
		if ($diff->y > 0 || $diff->m > 0 || $diff->d > 0) {
			return (string) $this->formatDateSpan($timestamp, $baseTimestamp, $l);
		}

		if ($diff->h > 0) {
			return (string) $l->n('%n hour ago', '%n hours ago', $diff->h);
		} else if ($diff->i > 0) {
			return (string) $l->n('%n minute ago', '%n minutes ago', $diff->i);
		}
		return (string) $l->t('seconds ago');
	}

	/**
	 * Formats the date and time of the given timestamp
	 *
	 * @param int|\DateTime $timestamp	Either a Unix timestamp or DateTime object
	 * @param string		$formatDate		See formatDate() for description
	 * @param string		$formatTime		See formatTime() for description
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted date and time string
	 */
	public function formatDateTime($timestamp, $formatDate = 'long', $formatTime = 'medium', \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		return $this->format($timestamp, 'datetime', $formatDate . '|' . $formatTime, $timeZone, $l);
	}

	/**
	 * Formats the date and time of the given timestamp
	 *
	 * @param int|\DateTime $timestamp	Either a Unix timestamp or DateTime object
	 * @param string	$formatDate		See formatDate() for description
	 * 					Uses 'Today', 'Yesterday' and 'Tomorrow' when applicable
	 * @param string	$formatTime		See formatTime() for description
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted relative date and time string
	 */
	public function formatDateTimeRelativeDay($timestamp, $formatDate = 'long', $formatTime = 'medium', \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		if (substr($formatDate, -1) !== '^' && substr($formatDate, -1) !== '*') {
			$formatDate .= '^';
		}

		return $this->format($timestamp, 'datetime', $formatDate . '|' . $formatTime, $timeZone, $l);
	}

	/**
	 * Formats the date and time of the given timestamp
	 *
	 * @param int|\DateTime $timestamp	Either a Unix timestamp or DateTime object
	 * @param string		$type		One of 'date', 'datetime' or 'time'
	 * @param string		$format		Format string
	 * @param \DateTimeZone	$timeZone	The timezone to use
	 * @param \OCP\IL10N	$l			The locale to use
	 * @return string Formatted date and time string
	 */
	protected function format($timestamp, $type, $format, \DateTimeZone $timeZone = null, \OCP\IL10N $l = null) {
		$l = $this->getLocale($l);
		$timeZone = $this->getTimeZone($timeZone);
		$timestamp = $this->getDateTime($timestamp, $timeZone);

		return (string) $l->l($type, $timestamp, [
			'width' => $format,
		]);
	}
}
