<?php
/**
 * webtrees: online genealogy
 * Copyright (C) 2017 webtrees development team
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */
namespace Fisharebest\Webtrees;

use Fisharebest\ExtCalendar\GregorianCalendar;
use Fisharebest\Webtrees\Date\CalendarDate;
use Fisharebest\Webtrees\Date\FrenchDate;
use Fisharebest\Webtrees\Date\GregorianDate;
use Fisharebest\Webtrees\Date\HijriDate;
use Fisharebest\Webtrees\Date\JalaliDate;
use Fisharebest\Webtrees\Date\JewishDate;
use Fisharebest\Webtrees\Date\JulianDate;
use Fisharebest\Webtrees\Date\RomanDate;

/**
 * A representation of GEDCOM dates and date ranges.
 *
 * Since different calendars start their days at different times, (civil
 * midnight, solar midnight, sunset, sunrise, etc.), we convert on the basis of
 * midday.
 *
 * We assume that years start on the first day of the first month. Where
 * this is not the case (e.g. England prior to 1752), we need to use modified
 * years or the OS/NS notation "4 FEB 1750/51".
 */
class Date {
	/** @var string Optional qualifier, such as BEF, FROM, ABT */
	public $qual1;

	/** @var CalendarDate  The first (or only) date */
	private $date1;

	/** @var string  Optional qualifier, such as TO, AND*/
	public $qual2;

	/** @var CalendarDate Optional second date */
	private $date2;

	/** @var string ptional text, as included with an INTerpreted date */
	private $text;

	/**
	 * Create a date, from GEDCOM data.
	 *
	 * @param string $date A date in GEDCOM format
	 */
	public function __construct($date) {
		// Extract any explanatory text
		if (preg_match('/^(.*) ?[(](.*)[)]/', $date, $match)) {
			$date       = $match[1];
			$this->text = $match[2];
		}
		if (preg_match('/^(FROM|BET) (.+) (AND|TO) (.+)/', $date, $match)) {
			$this->qual1 = $match[1];
			$this->date1 = $this->parseDate($match[2]);
			$this->qual2 = $match[3];
			$this->date2 = $this->parseDate($match[4]);
		} elseif (preg_match('/^(TO|FROM|BEF|AFT|CAL|EST|INT|ABT) (.+)/', $date, $match)) {
			$this->qual1 = $match[1];
			$this->date1 = $this->parseDate($match[2]);
		} else {
			$this->date1 = $this->parseDate($date);
		}
	}

	/**
	 * When we copy a date object, we need to create copies of
	 * its child objects.
	 */
	public function __clone() {
		$this->date1 = clone $this->date1;
		if (is_object($this->date2)) {
			$this->date2 = clone $this->date2;
		}
	}

	/**
	 * Convert a calendar date, such as "12 JUN 1943" into calendar date object.
	 *
	 * A GEDCOM date range may have two calendar dates.
	 *
	 * @param string $date
	 *
	 * @throws \DomainException
	 *
	 * @return CalendarDate
	 */
	private function parseDate($date) {
		// Valid calendar escape specified? - use it
		if (preg_match('/^(@#D(?:GREGORIAN|JULIAN|HEBREW|HIJRI|JALALI|FRENCH R|ROMAN)+@) ?(.*)/', $date, $match)) {
			$cal  = $match[1];
			$date = $match[2];
		} else {
			$cal = '';
		}
		// A date with a month: DM, M, MY or DMY
		if (preg_match('/^(\d?\d?) ?(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL|VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP|MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH|FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN) ?((?:\d{1,4}(?: B\.C\.)?|\d\d\d\d\/\d\d)?)$/', $date, $match)) {
			$d = $match[1];
			$m = $match[2];
			$y = $match[3];
		} elseif (preg_match('/^(\d{1,4}(?: B\.C\.)?|\d\d\d\d\/\d\d)$/', $date, $match)) {
			// A date with just a year
			$d = '';
			$m = '';
			$y = $match[1];
		} else {
			// An invalid date - do the best we can.
			$d = '';
			$m = '';
			$y = '';
			// Look for a 3/4 digit year anywhere in the date
			if (preg_match('/\b(\d{3,4})\b/', $date, $match)) {
				$y = $match[1];
			}
			// Look for a month anywhere in the date
			if (preg_match('/(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL|VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP|MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH|FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN)/', $date, $match)) {
				$m = $match[1];
				// Look for a day number anywhere in the date
				if (preg_match('/\b(\d\d?)\b/', $date, $match)) {
					$d = $match[1];
				}
			}
		}

		// Unambiguous dates - override calendar escape
		if (preg_match('/^(TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL)$/', $m)) {
			$cal = '@#DHEBREW@';
		} else {
			if (preg_match('/^(VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP)$/', $m)) {
				$cal = '@#DFRENCH R@';
			} else {
				if (preg_match('/^(MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH)$/', $m)) {
					$cal = '@#DHIJRI@'; // This is a WT extension
				} else {
					if (preg_match('/^(FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN)$/', $m)) {
						$cal = '@#DJALALI@'; // This is a WT extension
					} elseif (preg_match('/^\d{1,4}( B\.C\.)|\d\d\d\d\/\d\d$/', $y)) {
						$cal = '@#DJULIAN@';
					}
				}
			}
		}

		// Ambiguous dates - don't override calendar escape
		if ($cal == '') {
			if (preg_match('/^(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)$/', $m)) {
				$cal = '@#DGREGORIAN@';
			} else {
				if (preg_match('/^[345]\d\d\d$/', $y)) {
					// Year 3000-5999
					$cal = '@#DHEBREW@';
				} else {
					$cal = '@#DGREGORIAN@';
				}
			}
		}
		// Now construct an object of the correct type
		switch ($cal) {
			case '@#DGREGORIAN@':
				return new GregorianDate([$y, $m, $d]);
			case '@#DJULIAN@':
				return new JulianDate([$y, $m, $d]);
			case '@#DHEBREW@':
				return new JewishDate([$y, $m, $d]);
			case '@#DHIJRI@':
				return new HijriDate([$y, $m, $d]);
			case '@#DFRENCH R@':
				return new FrenchDate([$y, $m, $d]);
			case '@#DJALALI@':
				return new JalaliDate([$y, $m, $d]);
			case '@#DROMAN@':
				return new RomanDate([$y, $m, $d]);
			default:
				throw new \DomainException('Invalid calendar');
		}
	}

	/**
	 * A list of supported calendars and their names.
	 *
	 * @return string[]
	 */
	public static function calendarNames() {
		return [
			'gregorian' => /* I18N: The gregorian calendar */ I18N::translate('Gregorian'),
			'julian'    => /* I18N: The julian calendar */ I18N::translate('Julian'),
			'french'    => /* I18N: The French calendar */ I18N::translate('French'),
			'jewish'    => /* I18N: The Hebrew/Jewish calendar */ I18N::translate('Jewish'),
			'hijri'     => /* I18N: The Arabic/Hijri calendar */ I18N::translate('Hijri'),
			'jalali'    => /* I18N: The Persian/Jalali calendar */ I18N::translate('Jalali'),
		];
	}

	/**
	 * Convert a date to the preferred format and calendar(s) display.
	 *
	 * @param bool|null   $url               Wrap the date in a link to calendar.php
	 * @param string|null $date_format       Override the default date format
	 * @param bool|null   $convert_calendars Convert the date into other calendars
	 *
	 * @return string
	 */
	public function display($url = false, $date_format = null, $convert_calendars = true) {
		global $WT_TREE;

		$CALENDAR_FORMAT = $WT_TREE->getPreference('CALENDAR_FORMAT');

		if ($date_format === null) {
			$date_format = I18N::dateFormat();
		}

		if ($convert_calendars) {
			$calendar_format = explode('_and_', $CALENDAR_FORMAT);
		} else {
			$calendar_format = [];
		}

		// Two dates with text before, between and after
		$q1 = $this->qual1;
		$d1 = $this->date1->format($date_format, $this->qual1);
		$q2 = $this->qual2;
		if (is_null($this->date2)) {
			$d2 = '';
		} else {
			$d2 = $this->date2->format($date_format, $this->qual2);
		}
		// Con vert to other calendars, if requested
		$conv1 = '';
		$conv2 = '';
		foreach ($calendar_format as $cal_fmt) {
			if ($cal_fmt != 'none') {
				$d1conv = $this->date1->convertToCalendar($cal_fmt);
				if ($d1conv->inValidRange()) {
					$d1tmp = $d1conv->format($date_format, $this->qual1);
				} else {
					$d1tmp = '';
				}
				if (is_null($this->date2)) {
					$d2conv = null;
					$d2tmp  = '';
				} else {
					$d2conv = $this->date2->convertToCalendar($cal_fmt);
					if ($d2conv->inValidRange()) {
						$d2tmp = $d2conv->format($date_format, $this->qual2);
					} else {
						$d2tmp = '';
					}
				}
				// If the date is different from the unconverted date, add it to the date string.
				if ($d1 != $d1tmp && $d1tmp !== '') {
					if ($url) {
						if ($CALENDAR_FORMAT !== 'none') {
							$conv1 .= ' <span dir="' . I18N::direction() . '">(<a href="' . $d1conv->calendarUrl($date_format) . '" rel="nofollow">' . $d1tmp . '</a>)</span>';
						} else {
							$conv1 .= ' <span dir="' . I18N::direction() . '"><br><a href="' . $d1conv->calendarUrl($date_format) . '" rel="nofollow">' . $d1tmp . '</a></span>';
						}
					} else {
						$conv1 .= ' <span dir="' . I18N::direction() . '">(' . $d1tmp . ')</span>';
					}
				}
				if (!is_null($this->date2) && $d2 != $d2tmp && $d1tmp != '') {
					if ($url) {
						$conv2 .= ' <span dir="' . I18N::direction() . '">(<a href="' . $d2conv->calendarUrl($date_format) . '" rel="nofollow">' . $d2tmp . '</a>)</span>';
					} else {
						$conv2 .= ' <span dir="' . I18N::direction() . '">(' . $d2tmp . ')</span>';
					}
				}
			}
		}

		// Add URLs, if requested
		if ($url) {
			$d1 = '<a href="' . $this->date1->calendarUrl($date_format) . '" rel="nofollow">' . $d1 . '</a>';
			if (!is_null($this->date2)) {
				$d2 = '<a href="' . $this->date2->calendarUrl($date_format) . '" rel="nofollow">' . $d2 . '</a>';
			}
		}

		// Localise the date
		switch ($q1 . $q2) {
			case '':
				$tmp = $d1 . $conv1;
				break;
			case 'ABT':
				$tmp = /* I18N: Gedcom ABT dates */ I18N::translate('about %s', $d1 . $conv1);
				break;
			case 'CAL':
				$tmp = /* I18N: Gedcom CAL dates */ I18N::translate('calculated %s', $d1 . $conv1);
				break;
			case 'EST':
				$tmp = /* I18N: Gedcom EST dates */ I18N::translate('estimated %s', $d1 . $conv1);
				break;
			case 'INT':
				$tmp = /* I18N: Gedcom INT dates */ I18N::translate('interpreted %s (%s)', $d1 . $conv1, $this->text);
				break;
			case 'BEF':
				$tmp = /* I18N: Gedcom BEF dates */ I18N::translate('before %s', $d1 . $conv1);
				break;
			case 'AFT':
				$tmp = /* I18N: Gedcom AFT dates */ I18N::translate('after %s', $d1 . $conv1);
				break;
			case 'FROM':
				$tmp = /* I18N: Gedcom FROM dates */ I18N::translate('from %s', $d1 . $conv1);
				break;
			case 'TO':
				$tmp = /* I18N: Gedcom TO dates */ I18N::translate('to %s', $d1 . $conv1);
				break;
			case 'BETAND':
				$tmp = /* I18N: Gedcom BET-AND dates */ I18N::translate('between %s and %s', $d1 . $conv1, $d2 . $conv2);
				break;
			case 'FROMTO':
				$tmp = /* I18N: Gedcom FROM-TO dates */ I18N::translate('from %s to %s', $d1 . $conv1, $d2 . $conv2);
				break;
			default:
				$tmp = I18N::translate('Invalid date');
				break; // e.g. BET without AND
		}
		if ($this->text && !$q1) {
			$tmp = I18N::translate('%1$s (%2$s)', $tmp, $this->text);
		}

		if (strip_tags($tmp) === '') {
			return '';
		} else {
			return '<span class="date">' . $tmp . '</span>';
		}
	}

	/**
	 * Get the earliest calendar date from this GEDCOM date.
	 *
	 * In the date “FROM 1900 TO 1910”, this would be 1900.
	 *
	 * @return CalendarDate
	 */
	public function minimumDate() {
		return $this->date1;
	}

	/**
	 * Get the latest calendar date from this GEDCOM date.
	 *
	 * In the date “FROM 1900 TO 1910”, this would be 1910.
	 *
	 * @return CalendarDate
	 */
	public function maximumDate() {
		if (is_null($this->date2)) {
			return $this->date1;
		} else {
			return $this->date2;
		}
	}

	/**
	 * Get the earliest Julian day number from this GEDCOM date.
	 *
	 * @return int
	 */
	public function minimumJulianDay() {
		return $this->minimumDate()->minJD;
	}

	/**
	 * Get the latest Julian day number from this GEDCOM date.
	 *
	 * @return int
	 */
	public function maximumJulianDay() {
		return $this->maximumDate()->maxJD;
	}

	/**
	 * Get the middle Julian day number from the GEDCOM date.
	 *
	 * For a month-only date, this would be somewhere around the 16th day.
	 * For a year-only date, this would be somewhere around 1st July.
	 *
	 * @return int
	 */
	public function julianDay() {
		return (int) (($this->minimumJulianDay() + $this->maximumJulianDay()) / 2);
	}

	/**
	 * Offset this date by N years, and round to the whole year.
	 *
	 * This is typically used to create an estimated death date,
	 * which is before a certain number of years after the birth date.
	 *
	 * @param int     $years     a number of years, positive or negative
	 * @param string  $qualifier typically “BEF” or “AFT”
	 *
	 * @return Date
	 */
	public function addYears(int $years, string $qualifier = '') {
		$tmp = clone $this;
		$tmp->date1->y += $years;
		$tmp->date1->m = 0;
		$tmp->date1->d = 0;
		$tmp->date1->setJdFromYmd();
		$tmp->qual1 = $qualifier;
		$tmp->qual2 = '';
		$tmp->date2 = null;

		return $tmp;
	}

	/**
	 * Calculate the the age of a person, on a date.
	 *
	 * @param Date $d1
	 * @param Date $d2
	 * @param int  $format
	 *
	 * @throws \InvalidArgumentException
	 *
	 * @return int|string
	 */
	public static function getAge(Date $d1, Date $d2 = null, $format = 0) {
		if ($d2) {
			if ($d2->maximumJulianDay() >= $d1->minimumJulianDay() && $d2->minimumJulianDay() <= $d1->minimumJulianDay()) {
				// Overlapping dates
				$jd = $d1->minimumJulianDay();
			} else {
				// Non-overlapping dates
				$jd = $d2->minimumJulianDay();
			}
		} else {
			// If second date not specified, use today’s date
			$jd = WT_CLIENT_JD;
		}

		switch ($format) {
			case 0:
				// Years - integer only (for statistics, rather than for display)
				if ($jd && $d1->minimumJulianDay() && $d1->minimumJulianDay() <= $jd) {
					return $d1->minimumDate()->getAge(false, $jd, false);
				} else {
					return -1;
				}
			case 1:
				// Days - integer only (for sorting, rather than for display)
				if ($jd && $d1->minimumJulianDay()) {
					return $jd - $d1->minimumJulianDay();
				} else {
					return -1;
				}
			case 2:
				// Just years, in local digits, with warning for negative/
				if ($jd && $d1->minimumJulianDay()) {
					if ($d1->minimumJulianDay() > $jd) {
						return '<i class="icon-warning"></i>';
					} else {
						return I18N::number($d1->minimumDate()->getAge(false, $jd));
					}
				} else {
					return '';
				}
			default:
				throw new \InvalidArgumentException('format: ' . $format);
		}
	}

	/**
	 * Calculate the years/months/days between two events
	 * Return a gedcom style age string: "1y 2m 3d" (for fact details)
	 *
	 * @param Date      $d1
	 * @param Date|null $d2
	 *
	 * @return string
	 */
	public static function getAgeGedcom(Date $d1, Date $d2 = null) {
		if (is_null($d2)) {
			return $d1->date1->getAge(true, WT_CLIENT_JD, true);
		} else {
			// If dates overlap, then can’t calculate age.
			if (self::compare($d1, $d2)) {
				return $d1->date1->getAge(true, $d2->minimumJulianDay(), true);
			} elseif (self::compare($d1, $d2) == 0 && $d1->minimumJulianDay() == $d2->minimumJulianDay()) {
				return '0d';
			} else {
				return '';
			}
		}
	}

	/**
	 * Compare two dates, so they can be sorted.
	 *
	 * return <0 if $a<$b
	 * return >0 if $b>$a
	 * return  0 if dates same/overlap
	 * BEF/AFT sort as the day before/after
	 *
	 * @param Date $a
	 * @param Date $b
	 *
	 * @return int
	 */
	public static function compare(Date $a, Date $b) {
		// Get min/max JD for each date.
		switch ($a->qual1) {
			case 'BEF':
				$amin = $a->minimumJulianDay() - 1;
				$amax = $amin;
				break;
			case 'AFT':
				$amax = $a->maximumJulianDay() + 1;
				$amin = $amax;
				break;
			default:
				$amin = $a->minimumJulianDay();
				$amax = $a->maximumJulianDay();
				break;
		}
		switch ($b->qual1) {
			case 'BEF':
				$bmin = $b->minimumJulianDay() - 1;
				$bmax = $bmin;
				break;
			case 'AFT':
				$bmax = $b->maximumJulianDay() + 1;
				$bmin = $bmax;
				break;
			default:
				$bmin = $b->minimumJulianDay();
				$bmax = $b->maximumJulianDay();
				break;
		}
		if ($amax < $bmin) {
			return -1;
		} elseif ($amin > $bmax && $bmax > 0) {
			return 1;
		} elseif ($amin < $bmin && $amax <= $bmax) {
			return -1;
		} elseif ($amin > $bmin && $amax >= $bmax && $bmax > 0) {
			return 1;
		} else {
			return 0;
		}
	}

	/**
	 * Check whether a gedcom date contains usable calendar date(s).
	 *
	 * An incomplete date such as "12 AUG" would be invalid, as
	 * we cannot sort it.
	 *
	 * @return bool
	 */
	public function isOK() {
		return $this->minimumJulianDay() && $this->maximumJulianDay();
	}

	/**
	 * Calculate the gregorian year for a date. This should NOT be used internally
	 * within WT - we should keep the code "calendar neutral" to allow support for
	 * jewish/arabic users. This is only for interfacing with external entities,
	 * such as the ancestry.com search interface or the dated fact icons.
	 *
	 * @return int
	 */
	public function gregorianYear() {
		if ($this->isOK()) {
			$gregorian_calendar = new GregorianCalendar;
			list($year)         = $gregorian_calendar->jdToYmd($this->julianDay());

			return $year;
		} else {
			return 0;
		}
	}
}
