<?php

namespace Common;

/**
 * Date class
 */
class Date {

  /**
	 * Fuzzy date strings
	 *
	 * @var  array
	 */
	protected $_time_formats = array(
		array(60, 'just now'),
		array(90, '1 minute'),
		array(3600, 'minutes', 60),
		array(5400, '1 hour'),
		array(86400, 'hours', 3600),
		array(129600, '1 day'),
		array(604800, 'days', 86400),
		array(907200, '1 week'),
		array(2628000, 'weeks', 604800),
		array(3942000, '1 month'),
		array(31536000, 'months', 2628000),
		array(47304000, '1 year'),
		array(3153600000, 'years', 31536000)
	);

	protected $_time_format = 'H:i';


	/**
	 * Timestamp
	 *
	 * @var  DateTime
	 */
	protected $_timestamp = null;


	/**
	 * Use current timestamp
	 *
	 * @return  Date
	 */
	static public function now() {
		return self::with('now');
	}


	/**
	 * Specified time
	 *
	 * @param   int|string  $date
	 * @return  Date
	 */
	static public function with($date) {
		return new self($date);
	}


	/**
	 * Constructor
	 *
	 * @param  int|string  $date
	 */
	public function __construct($date) {
		// If the timestamp is not valid, set the timestamp to now
		if (($this->_timestamp = strtotime($date)) === false) {
			$this->_timestamp = strtotime('now');
		}
	}


	/**
	 * Pretty formatted date. Yes, this is an actual method. Deal with it!
	 *
	 * @return  string
	 */
	public function pretty_date($time = true) {
		return $this->formatted('F j, Y'.($time ? ' '.$this->_time_format : ''));
	}


	/**
	 * Timezone string. Or timezone abbreviation
	 *
	 * @param   bool  $abbrev
	 * @return  string
	 */
	public function timezone($abbrev = false) {
		$abbrev = ($abbrev) ? 'T' : 'e';

		return $this->formatted($abbrev);
	}


	/**
	 * Timezone offset in seconds
	 *
	 * @return  string
	 */
	public function timezone_offset() {
		return $this->formatted('z');
	}


	/**
	 * Difference to Greenwich time (GMT)
	 *
	 * @param   bool  $colon
	 * @return  string
	 */
	public function gmt_diff($colon = false) {
		$colon = ($colon) ? 'P' : 'O';

		return $this->formatted($colon);
	}


	/**
	 * Current timestamp
	 *
	 * @return  int
	 */
	public function timestamp() {
		return (int) $this->formatted('U');
	}


	/**
	 * Day
	 *
	 * @param   bool  $text
	 * @param   bool  $full
	 * @return  string
	 */
	public function day($text = false, $full = true) {
		if ($text) {
			return $this->day_text($full);
		}

		return $this->day_num($full);
	}


	/**
	 * Day of month. Optionally with leading 0
	 *
	 * @param   bool  $leading
	 * @return  string
	 */
	public function day_num($leading = false) {
		$leading = ($leading) ? 'd' : 'j';

		return $this->formatted($leading);
	}


	/**
	 * A textual representation of a day
	 *
	 * @param   bool  $full
	 * @return  string
	 */
	public function day_text($full = true) {
		$full = ($full) ? 'l' : 'D';

		return $this->formatted($full);
	}

	/**
	 * English ordinal suffix for the day of the month, 2 characters
	 *
	 * @return  string
	 */
	public function ordinal() {
		return $this->formatted('S');
	}


	/**
	 * Numeric representation of the day of the week
	 *
	 * @param   bool  $iso8601
	 * @return  string
	 */
	public function day_of_week($iso8601 = false) {
		$iso8601 = ($iso8601) ? 'N' : 'w';

		return $this->formatted($iso8601);
	}


	/**
	 * The day of the year (starting from 0)
	 *
	 * @return  string
	 */
	public function day_of_year() {
		return $this->formatted('z');
	}


	/**
	 * Number of days in the given month
	 *
	 * @return  string
	 */
	public function days_in_month() {
		return $this->formatted('t');
	}


	/**
	 * Month
	 *
	 * @param   bool  $text
	 * @param   bool  $full
	 * @return  string
	 */
	public function month($text = false, $full = true) {
		if ($text) {
			return $this->monthText($full);
		}

		return $this->month_num($full);
	}


	/**
	 * Numeric representation of a month
	 *
	 * @param   bool  $leading
	 * @return  string
	 */
	public function month_num($leading = true) {
		$leading = ($leading) ? 'm' : 'n';

		return $this->formatted($leading);
	}


	/**
	 * A textual representation of a month
	 *
	 * @param   bool  $abbrev
	 * @return  string
	 */
	public function monthText($abbrev = true) {
		$abbrev = ($abbrev) ? 'M' : 'F';

		return $this->formatted($abbrev);
	}


	/**
	 * ISO-8601 week number of year, weeks starting on Monday
	 *
	 * @return  string
	 */
	public function week_of_year() {
		return $this->formatted('W');
	}


	/**
	 * Year representation
	 *
	 * @param   bool  $full
	 * @return  string
	 */
	public function year($full = true) {
		$full = ($full) ? 'Y' : 'y';

		return $this->formatted($full);
	}


	/**
	 * Whether it's a leap year
	 *
	 * @return  bool
	 */
	public function leapyear() {
		return (bool) $this->formatted('L');
	}


	/**
	 * 12 or 24-hour format of an hour with or without leading zeros
	 *
	 * @param   bool  $leading
	 * @param   bool  $military
	 * @return  string
	 */
	public function hour($leading = true, $military = true) {
		if ($military) {
			return $this->hour12($leading);
		}

		return $this->hour24($leading);
	}


	/**
	 * 12-hour format of an hour with or without leading zeros
	 *
	 * @param   bool  $leading
	 * @return  string
	 */
	public function hour12($leading = true) {
		$format = ($leading) ? 'h' : 'g';

		return $this->formatted($format);
	}


	/**
	 * 24-hour format of an hour with or without leading zeros
	 *
	 * @param   bool  $leading
	 * @return  string
	 */
	public function hour24($leading = true) {
		$format = ($leading) ? 'H' : 'G';

		return $this->formatted($format);
	}


	/**
	 * Minutes with leading zeros
	 *
	 * @return  string
	 */
	public function minutes() {
		return $this->formatted('i');
	}


	/**
	 * Seconds with leading zeros
	 *
	 * @return  string
	 */
	public function seconds() {
		return $this->formatted('s');
	}


	/**
	 * Microseconds
	 *
	 * @return  string
	 */
	public function microseconds() {
		return $this->formatted('u');
	}


	/**
	 * Ante meridiem or Post meridiem
	 *
	 * @param   bool  $upper
	 * @return  string
	 */
	public function meridiem($upper = true) {
		$upper = ($upper) ? 'A' : 'a';

		return $this->formatted($upper);
	}


	/**
	 * Whether or not the date is in daylight saving time
	 *
	 * @return  bool
	 */
	public function daylight_saving() {
		return (bool) $this->formatted('I');
	}


	/**
	 * ISO 8601 date (eg. 2004-02-12T15:19:21+00:00)
	 *
	 * @param 	bool	$utc
	 * @return  string
	 */
	public function iso8601($utc = false) {
		return $utc ? gmdate('c', $this->_timestamp) : $this->formatted('c');
	}

	/**
	 * RFC 2822 formatted date (eg. Thu, 21 Dec 2000 16:01:07 +0200)
	 *
	 * @return  string
	 */
	public function rfc2822() {
		return $this->formatted('r');
	}


	/**
	 * Find the age in years
	 *
	 * @return  int
	 */
	public function age() {
		// Current
		$now = self::now();

		// Differences
		$year_diff  = $now->year() - $this->year();
		$month_diff = $now->month_num() - $this->month_num();
		$day_diff   = $now->day_num() - $this->day_num();

		if ($day_diff < 0 || $month_diff < 0) {
			$year_diff --;
		}

		return $year_diff;
	}

	/**
	 * Find MySQL Date format (eg. 2014-02-25 00:00:00)
	 *
	 * @return string
	 */
	public function mysql($time = true) {
		return $this->formatted('Y-m-d'.($time ? ' H:i:s' : ''));
	}


	/**
	 * Find the relative date
	 *
	 * @return  string
	 */
	public function fuzzy($append = 'ago') {
		// Difference between now and the passed date
		$diff = time() - $this->_timestamp;

		$val = '';

		// Waaaayyyy to long ago (earlier than 1970)
		if ($this->_timestamp <= 0) {
			// A long time ago... in a galaxy far, far away
			$val = 'a long time '.$append;
		}

		// Future date
		else if ($diff < 0) {
			$val = 'in the future';
		}

		// Past date
		else {
			// Loop through each format measurement
			foreach ($this->_time_formats as $format) {
				// if the difference from now and passed time is less than first option in format measurement
				if ($diff < $format[0]) {
					// If the format array item has no calculation value
					if (count($format) == 2) {
						$val = $format[1].($format[0] === 60 ? '' : ' '.$append);

						break;
					}

					// Divide difference by format item value to get number of units
					else {
						$val = ceil($diff / $format[2]).' '.$format[1].' '.$append;

						break;
					}
				}
			}
		}

		return $val;
	}

	public function short($time = true) {
		return $this->formatted('m/d/Y'.($time ? ' '.$this->_time_format : ''));
	}


	/**
	 * Generic date format. See http://php.net/manual/en/function.date.php
	 *
	 * @param   string  $format
	 * @return  mixed
	 */
	public function formatted($format = null) {
		$format = $format ? : 'F j, Y, '.$this->_time_format.' T';
		return date($format, $this->_timestamp);
	}

}