<?php
/**
 * Date Functions
 *
 * @package WP_Ultimo\Functions
 * @since   2.0.0
 */

// Exit if accessed directly
defined('ABSPATH') || exit;

/**
 * Checks if a date is valid in the Gregorian calendar.
 *
 * @since 2.0.0
 *
 * @param string|false|null $date Date to check.
 * @param string            $format Format to check against.
 * @return bool
 */
function wu_validate_date($date, $format = 'Y-m-d H:i:s') {

	if (is_null($date)) {
		return true;
	} elseif ( ! $date) {
		return false;
	}

	try {
		$d = \DateTime::createFromFormat($format, $date);
	} catch (\Throwable $exception) {
		return false;
	}

	return $d && $d->format($format) === $date;
}

/**
 * Returns a Carbon object to deal with dates in a more compelling way.
 *
 * Note: this function uses the wu_validate function to check
 * if the string passed is a valid date string. If the string
 * is not valid, now is used.
 *
 * @since 2.0.0
 * @see https://carbon.nesbot.com/docs/
 *
 * @param string|false $date Parsable date string.
 * @return \DateTime
 */
function wu_date($date = false) {

	if ( ! wu_validate_date($date)) {
		$date = date_i18n('Y-m-d H:i:s');
	}

	return \DateTime::createFromFormat('Y-m-d H:i:s', $date);
}

/**
 * Returns how many days ago the first date was in relation to the second date.
 *
 * If second date is empty, now is used.
 *
 * @since 1.7.0
 *
 * @param string       $date_1 First date to compare.
 * @param string|false $date_2 Second date to compare.
 * @return integer Negative if days ago, positive if days in the future.
 */
function wu_get_days_ago($date_1, $date_2 = false) {

	$datetime_1 = wu_date($date_1);

	$datetime_2 = wu_date($date_2);

	$dateIntervar = $datetime_1->diff($datetime_2, false);

	return - $dateIntervar->days;
}

/**
 * Returns the current time from the network
 *
 * @param string $type Type of the return string to return.
 * @param bool   $gmt If the date returned should be GMT or not.
 * @return string
 */
function wu_get_current_time($type = 'mysql', $gmt = false) {

	switch_to_blog(wu_get_main_site_id());

		$time = current_time($type, $gmt); // phpcs:ignore

	restore_current_blog();

	return $time;
}

/**
 * Returns a more user friendly version of the duration unit string.
 *
 * @since 2.0.0
 *
 * @param string $unit The duration unit string.
 * @param int    $length The duration.
 * @return string
 */
function wu_filter_duration_unit($unit, $length) {

	$new_unit = '';

	switch ($unit) {
		case 'day':
			$new_unit = $length > 1 ? __('Days', 'wp-ultimo') : __('Day', 'wp-ultimo');
			break;
		case 'month':
			$new_unit = $length > 1 ? __('Months', 'wp-ultimo') : __('Month', 'wp-ultimo');
			break;
		case 'year':
			$new_unit = $length > 1 ? __('Years', 'wp-ultimo') : __('Year', 'wp-ultimo');
			break;
		default:
			$new_unit = $new_unit;
			break;
	}

	return $new_unit;
}

/**
 * Get the human time diff.
 *
 * @since 2.0.0
 *
 * @param string $from  The time to calculate from.
 * @param string $limit The limit to switch back to a normal date representation.
 * @param string $to    The date to compare against.
 */
function wu_human_time_diff($from, $limit = '-5 days', $to = false): string {

	$timestamp_from = is_numeric($from) ? $from : strtotime(get_date_from_gmt($from));

	$limit = strtotime($limit);

	if ($timestamp_from <= $limit) {

		// translators: %s: date.
		return sprintf(__('on %s', 'wp-ultimo'), date_i18n(get_option('date_format'), $timestamp_from));
	}

	if (false === $to) {
		$to = wu_get_current_time('timestamp'); // phpcs:ignore
	}

	$placeholder = wu_get_current_time('timestamp') > $timestamp_from ? __('%s ago', 'wp-ultimo') : __('In %s', 'wp-ultimo'); // phpcs:ignore

	return sprintf($placeholder, human_time_diff($timestamp_from, $to));
}

/**
 * Converts php DateTime format to Javascript Moment format.
 *
 * @since 2.0.10
 *
 * @param string $php_date_format The PHP date format to convert.
 * @return string The moment.js date format
 */
function wu_convert_php_date_format_to_moment_js_format($php_date_format): string {

	$replacements = [
		'A' => 'A',      // for the sake of escaping below
		'a' => 'a',      // for the sake of escaping below
		'B' => '',       // Swatch internet time (.beats), no equivalent
		'c' => 'YYYY-MM-DD[T]HH:mm:ssZ', // ISO 8601
		'D' => 'ddd',
		'd' => 'DD',
		'e' => 'zz',     // deprecated since version 1.6.0 of moment.js
		'F' => 'MMMM',
		'G' => 'H',
		'g' => 'h',
		'H' => 'HH',
		'h' => 'hh',
		'I' => '',       // Daylight Saving Time? => moment().isDST();
		'i' => 'mm',
		'j' => 'D',
		'L' => '',       // Leap year? => moment().isLeapYear();
		'l' => 'dddd',
		'M' => 'MMM',
		'm' => 'MM',
		'N' => 'E',
		'n' => 'M',
		'O' => 'ZZ',
		'o' => 'YYYY',
		'P' => 'Z',
		'r' => 'ddd, DD MMM YYYY HH:mm:ss ZZ', // RFC 2822
		'S' => 'o',
		's' => 'ss',
		'T' => 'z',      // deprecated since version 1.6.0 of moment.js
		't' => '',       // days in the month => moment().daysInMonth();
		'U' => 'X',
		'u' => 'SSSSSS', // microseconds
		'v' => 'SSS',    // milliseconds (from PHP 7.0.0)
		'W' => 'W',      // for the sake of escaping below
		'w' => 'e',
		'Y' => 'YYYY',
		'y' => 'YY',
		'Z' => '',       // time zone offset in minutes => moment().zone();
		'z' => 'DDD',
	];

	// Converts escaped characters.
	foreach ($replacements as $from => $to) {
		$replacements[ '\\' . $from ] = '[' . $from . ']';
	}

	return strtr($php_date_format, $replacements);
}