<?php

use Pods\Static_Cache;
use Pods\Whatsit\Field;

/**
 * @package Pods\Fields
 */
class PodsField_DateTime extends PodsField {

	/**
	 * {@inheritdoc}
	 */
	public static $group = 'Date / Time';

	/**
	 * {@inheritdoc}
	 */
	public static $type = 'datetime';

	/**
	 * {@inheritdoc}
	 */
	public static $label = 'Date / Time';

	/**
	 * {@inheritdoc}
	 */
	public static $prepare = '%s';

	/**
	 * Storage format.
	 *
	 * @var string
	 * @since 2.7.0
	 */
	public static $storage_format = 'Y-m-d H:i:s';

	/**
	 * The default empty value (database)
	 *
	 * @var string
	 * @since 2.7.0
	 */
	public static $empty_value = '0000-00-00 00:00:00';

	/**
	 * {@inheritdoc}
	 */
	public function setup() {

		static::$group = __( 'Date / Time', 'pods' );
		static::$label = __( 'Date / Time', 'pods' );
	}

	/**
	 * {@inheritdoc}
	 */
	public function options() {

		$options = array(
			static::$type . '_type'                  => array(
				'label'      => __( 'Date Format Type', 'pods' ),
				'default'    => 'format',
				// Backwards compatibility
				'type'       => 'pick',
				'help'       => __( 'WordPress Default is the format used in Settings, General under "Date Format".', 'pods' ) . '<br>' . __( 'Predefined Format will allow you to select from a list of commonly used date formats.', 'pods' ) . '<br>' . __( 'Custom will allow you to enter your own using PHP Date/Time Strings.', 'pods' ),
				'data'       => array(
					'wp'     => __( 'WordPress default', 'pods' ) . ': ' . date_i18n( get_option( 'date_format' ) ),
					'format' => __( 'Predefined format', 'pods' ),
					'custom' => __( 'Custom format', 'pods' ),
				),
				'pick_show_select_text' => 0,
				'dependency' => true,
			),
			static::$type . '_format_custom'         => array(
				'label'      => __( 'Date Format for Display', 'pods' ),
				'depends-on' => array( static::$type . '_type' => 'custom' ),
				'default'    => '',
				'type'       => 'text',
				'help'       => sprintf(
					'<a href="https://docs.pods.io/fields/date-time-fields/datetime/" target="_blank" rel="noopener noreferrer">%1$s</a>',
					esc_html__( 'Date / Time field documentation', 'pods' )
				),
			),
			static::$type . '_format_custom_js'      => array(
				'label'      => __( 'Date Format for Input', 'pods' ),
				'depends-on' => array( static::$type . '_type' => 'custom' ),
				'default'    => '',
				'type'       => 'text',
				'help'       => sprintf(
					'<a href="https://docs.pods.io/fields/date-time-fields/datetime/" target="_blank" rel="noopener noreferrer">%1$s</a><br />%2$s',
					esc_html__( 'Date / Time field documentation', 'pods' ),
					esc_html__( 'Leave empty to auto-generate from PHP format.', 'pods' )
				),
			),
			static::$type . '_format'                => array(
				'label'      => __( 'Date Format (predefined)', 'pods' ),
				'depends-on' => array( static::$type . '_type' => 'format' ),
				'default'    => 'mdy',
				'type'       => 'pick',
				'data'       => array(
					'mdy'       => date_i18n( 'm/d/Y' ),
					'mdy_dash'  => date_i18n( 'm-d-Y' ),
					'mdy_dot'   => date_i18n( 'm.d.Y' ),
					'ymd_slash' => date_i18n( 'Y/m/d' ),
					'ymd_dash'  => date_i18n( 'Y-m-d' ),
					'ymd_dot'   => date_i18n( 'Y.m.d' ),
					'fjy'       => date_i18n( 'F j, Y' ),
					'fjsy'      => date_i18n( 'F jS, Y' ),
					'c'         => date_i18n( 'c' ),
				),
				'pick_show_select_text' => 0,
				'dependency' => true,
			),
			static::$type . '_time_type'             => array(
				'label'       => __( 'Time Format Type', 'pods' ),
				'excludes-on' => array( static::$type . '_format' => 'c' ),
				'default'     => '12',
				// Backwards compatibility
				'type'        => 'pick',
				'help'        => __( 'WordPress Default is the format used in Settings, General under "Time Format".', 'pods' ) . '<br>' . __( '12/24 hour will allow you to select from a list of commonly used time formats.', 'pods' ) . '<br>' . __( 'Custom will allow you to enter your own using PHP Date/Time Strings.', 'pods' ),
				'data'        => array(
					'wp'     => __( 'WordPress default', 'pods' ) . ': ' . date_i18n( get_option( 'time_format' ) ),
					'12'     => __( '12 hour', 'pods' ),
					'24'     => __( '24 hour', 'pods' ),
					'custom' => __( 'Custom', 'pods' ),
				),
				'pick_show_select_text' => 0,
				'dependency'  => true,
			),
			static::$type . '_time_format_custom'    => array(
				'label'       => __( 'Time Format for Display', 'pods' ),
				'depends-on'  => array( static::$type . '_time_type' => 'custom' ),
				'excludes-on' => array( static::$type . '_format' => 'c' ),
				'default'     => '',
				'type'        => 'text',
				'help'       => sprintf(
					'<a href="https://docs.pods.io/fields/date-time-fields/datetime/" target="_blank" rel="noopener noreferrer">%1$s</a>',
					esc_html__( 'Date / Time field documentation', 'pods' )
				),
			),
			static::$type . '_time_format_custom_js' => array(
				'label'       => __( 'Time Format for Input', 'pods' ),
				'depends-on'  => array( static::$type . '_time_type' => 'custom' ),
				'excludes-on' => array( static::$type . '_format' => 'c' ),
				'default'     => '',
				'type'        => 'text',
				'help'       => sprintf(
					'<a href="https://docs.pods.io/fields/date-time-fields/datetime/" target="_blank" rel="noopener noreferrer">%1$s</a><br />%2$s',
					esc_html__( 'Date / Time field documentation', 'pods' ),
					esc_html__( 'Leave empty to auto-generate from PHP format.', 'pods' )
				),
			),
			static::$type . '_time_format'           => array(
				'label'       => __( 'Time Format (12 hour)', 'pods' ),
				'depends-on'  => array( static::$type . '_time_type' => '12' ),
				'excludes-on' => array( static::$type . '_format' => 'c' ),
				'default'     => 'h_mma',
				'type'        => 'pick',
				'data'        => array(
					'h_mm_A'     => date_i18n( 'g:i A' ),
					'h_mm_ss_A'  => date_i18n( 'g:i:s A' ),
					'hh_mm_A'    => date_i18n( 'h:i A' ),
					'hh_mm_ss_A' => date_i18n( 'h:i:s A' ),
					'h_mma'      => date_i18n( 'g:ia' ),
					'hh_mma'     => date_i18n( 'h:ia' ),
					'h_mm'       => date_i18n( 'g:i' ),
					'h_mm_ss'    => date_i18n( 'g:i:s' ),
					'hh_mm'      => date_i18n( 'h:i' ),
					'hh_mm_ss'   => date_i18n( 'h:i:s' ),
				),
				'pick_show_select_text' => 0,
			),
			static::$type . '_time_format_24'        => array(
				'label'       => __( 'Time Format (24 hour)', 'pods' ),
				'depends-on'  => array( static::$type . '_time_type' => '24' ),
				'excludes-on' => array( static::$type . '_format' => 'c' ),
				'default'     => 'hh_mm',
				'type'        => 'pick',
				'data'        => array(
					'hh_mm'    => date_i18n( 'H:i' ),
					'hh_mm_ss' => date_i18n( 'H:i:s' ),
				),
				'pick_show_select_text' => 0,
			),
			static::$type . '_year_range_custom' => array(
				'label'   => __( 'Year Range', 'pods' ),
				'default' => '',
				'type'    => 'text',
				'help'    => sprintf(
					'%1$s<br /><a href="https://docs.pods.io/fields/date-time-fields/datetime/" target="_blank" rel="noopener noreferrer">%2$s</a>',
					sprintf(
						esc_html__( 'Example: %1$s for specifying a hard coded year range or %2$s for the last and next 10 years.', 'pods' ),
						'<code>2010:2030</code>',
						'<code>-10:+10</code>'
					),
					esc_html__( 'Date / Time field documentation', 'pods' )
				),
			),
			static::$type . '_allow_empty'           => array(
				'label'   => __( 'Allow empty value', 'pods' ),
				'default' => 1,
				'type'    => 'boolean',
			),
			static::$type . '_html5'                 => array(
				'label'   => __( 'Enable HTML5 Input Field', 'pods' ),
				'default' => apply_filters( 'pods_form_ui_field_html5', 0, static::$type ),
				'type'    => 'boolean',
			),
		);

		// Check if PHP DateTime::createFromFormat exists for additional supported formats
		if ( method_exists( 'DateTime', 'createFromFormat' ) || apply_filters( 'pods_form_ui_field_datetime_custom_formatter', false ) ) {
			$options[ static::$type . '_format' ]['data'] = array_merge(
				$options[ static::$type . '_format' ]['data'], array(
					'dmy'      => date_i18n( 'd/m/Y' ),
					'dmy_dash' => date_i18n( 'd-m-Y' ),
					'dmy_dot'  => date_i18n( 'd.m.Y' ),
					'dMy'      => date_i18n( 'd/M/Y' ),
					'dMy_dash' => date_i18n( 'd-M-Y' ),
				)
			);
		}

		$options[ static::$type . '_format' ]['data']    = apply_filters( 'pods_form_ui_field_date_format_options', $options[ static::$type . '_format' ]['data'] );
		$options[ static::$type . '_format' ]['default'] = apply_filters( 'pods_form_ui_field_date_format_default', $options[ static::$type . '_format' ]['default'] );

		$options[ static::$type . '_time_type' ]['default']      = apply_filters( 'pods_form_ui_field_time_format_type_default', $options[ static::$type . '_time_type' ]['default'] );
		$options[ static::$type . '_time_format' ]['data']       = apply_filters( 'pods_form_ui_field_time_format_options', $options[ static::$type . '_time_format' ]['data'] );
		$options[ static::$type . '_time_format' ]['default']    = apply_filters( 'pods_form_ui_field_time_format_default', $options[ static::$type . '_time_format' ]['default'] );
		$options[ static::$type . '_time_format_24' ]['data']    = apply_filters( 'pods_form_ui_field_time_format_24_options', $options[ static::$type . '_time_format_24' ]['data'] );
		$options[ static::$type . '_time_format_24' ]['default'] = apply_filters( 'pods_form_ui_field_time_format_24_default', $options[ static::$type . '_time_format_24' ]['default'] );

		return $options;
	}

	/**
	 * {@inheritdoc}
	 */
	public function schema( $options = null ) {

		$schema = 'DATETIME NOT NULL default "0000-00-00 00:00:00"';

		return $schema;
	}

	/**
	 * {@inheritdoc}
	 */
	public function is_empty( $value = null ) {

		$is_empty = false;

		$value = trim( $value );

		if ( empty( $value ) || in_array( $value, array( '0000-00-00', '0000-00-00 00:00:00' ), true ) ) {
			$is_empty = true;
		}

		return $is_empty;

	}

	/**
	 * {@inheritdoc}
	 */
	public function display( $value = null, $name = null, $options = null, $pod = null, $id = null ) {

		$value = $this->format_value_display( $value, $options, false );

		return $value;
	}

	/**
	 * {@inheritdoc}
	 */
	public function input( $name, $value = null, $options = null, $pod = null, $id = null ) {

		$options         = ( is_array( $options ) || is_object( $options ) ) ? $options : (array) $options;
		$form_field_type = PodsForm::$field_type;

		$value = $this->normalize_value_for_input( $value, $options );

		// @todo Remove? Format Value (done in field template).
		//$value = $this->format_value_display( $value, $options, true );

		$field_type = static::$type;

		$is_read_only = (boolean) pods_v( 'read_only', $options, false );

		if ( isset( $options['name'] ) && ! pods_permission( $options ) ) {
			if ( $is_read_only ) {
				$options['readonly'] = true;

				$field_type = 'text';
			} else {
				return;
			}
		} elseif ( ! pods_has_permissions( $options ) && $is_read_only ) {
			$options['readonly'] = true;

			$field_type = 'text';
		}

		if ( ! empty( $options['disable_dfv'] ) ) {
			return pods_view( PODS_DIR . 'ui/fields/' . $field_type . '.php', compact( array_keys( get_defined_vars() ) ) );
		}

		// Convert the date/time formats to MomentJS.
	    $options = $this->prepare_options_for_moment_js( $options );

		$type = pods_v( 'type', $options, static::$type );

		$args = compact( array_keys( get_defined_vars() ) );
		$args = (object) $args;

		$this->render_input_script( $args );
	}

	/**
	 * {@inheritdoc}
	 */
	public function validate( $value, $name = null, $options = null, $fields = null, $pod = null, $id = null, $params = null ) {
		$validate = parent::validate( $value, $name, $options, $fields, $pod, $id, $params );

		$errors = array();

		if ( is_array( $validate ) ) {
			$errors = $validate;
		}

		if ( ! $this->is_empty( $value ) ) {

			// Value should always be passed as storage format since 2.7.15.
			// This was broken since 2.8.x and restored in 2.9.2 (#6389).
			$formats = [
				static::$storage_format,
			];

			if ( ! $this->is_storage_format( $value ) ) {
				// Allow input values compatible with the input (JS) or display (PHP) formats.
				$formats = [
					$this->format_display( $options, true ),
					$this->format_display( $options, false ),
				];

				$formats = array_unique( array_filter( $formats ) );
			}

			$check = $this->convert_date( $value, static::$storage_format, $formats, true );

			if ( false === $check ) {
				$label = pods_v( 'label', $options, ucwords( str_replace( '_', ' ', $name ) ) );

				// Translators: %1$s is the field label and %2$s is the input value.
				$errors[] = sprintf( esc_html__( '%1$s was not provided in a recognizable format: "%2$s"', 'pods' ), $label, $value );
			}
		}

		if ( ! empty( $errors ) ) {
			return $errors;
		}

		return $validate;
	}

	/**
	 * {@inheritdoc}
	 */
	public function pre_save( $value, $id = null, $name = null, $options = null, $fields = null, $pod = null, $params = null ) {

		// Value should always be passed as storage format since 2.7.15.
		$format = static::$storage_format;

		if ( ! $this->is_empty( $value ) ) {
			if ( ! $this->is_storage_format( $value ) ) {
				// Allow input values compatible with the display format.
				$format = $this->format_display( $options, false );
			}
			$value = $this->convert_date( $value, static::$storage_format, $format );
		} elseif ( pods_v( static::$type . '_allow_empty', $options, 1 ) ) {
			$value = static::$empty_value;
		} else {
			$value = date_i18n( static::$storage_format );
		}

		return $value;
	}

	/**
	 * {@inheritdoc}
	 */
	public function ui( $id, $value, $name = null, $options = null, $fields = null, $pod = null ) {

		$value = $this->display( $value, $name, $options, $pod, $id );

		if ( $this->is_empty( $value ) && pods_v( static::$type . '_allow_empty', $options, 1 ) ) {
			$value = false;
		}

		return $value;
	}

	/**
	 * Convert value to the correct format for display.
	 *
	 * @param string $value   Field value.
	 * @param array  $options Field options.
	 * @param bool   $js      Return formatted from jQuery UI format? (only for custom formats).
	 *
	 * @return string
	 * @since 2.7.0
	 */
	public function format_value_display( $value, $options, $js = false ) {

		$format = $this->format_display( $options, $js );

		if ( ! $this->is_empty( $value ) ) {
			// Try default storage format.
			$date = $this->createFromFormat( static::$storage_format, (string) $value );

			// Convert to timestamp.
			if ( $date instanceof DateTime ) {
				$timestamp = $date->getTimestamp();
			} else {
				// Try field format.
				$date_local = $this->createFromFormat( $format, (string) $value );

				if ( $date_local instanceof DateTime ) {
					$timestamp = $date_local->getTimestamp();
				} else {
					// Fallback.
					$timestamp = strtotime( (string) $value );
				}
			}

			$value = date_i18n( $format, $timestamp );
		} elseif ( ! pods_v( static::$type . '_allow_empty', $options, 1 ) ) {
			$value = date_i18n( $format );
		} else {
			$value = '';
		}

		return $value;
	}

	/**
	 * Build date and/or time display format string based on options
	 *
	 * @since 2.7.13
	 *
	 * @param  array $options Field options.
	 * @param  bool  $js      Whether to return format for jQuery UI.
	 *
	 * @return string
	 */
	public function format_display( $options, $js = false ) {

		if ( 'custom' === pods_v( static::$type . '_type', $options, 'format' ) ) {
			if ( $js ) {

				// Gets format strings in jQuery UI format.
				$date = $this->format_date( $options, $js );
				$time = $this->format_time( $options, $js );

				// Convert them to PHP date format.
				$date = $this->convert_format( $date, array( 'source' => 'jquery_ui', 'type' => 'date' ) );
				$time = $this->convert_format( $time, array( 'source' => 'jquery_ui', 'type' => 'time' ) );

				return $date . ' ' . $time;

			} else {
				$format = $this->format_datetime( $options, $js );
			}
		} else {
			$js = false;
			$format = $this->format_datetime( $options, $js );
		}

		return $format;
	}

	/**
	 * Build date and/or time format string based on options
	 *
	 * @since 2.7.0
	 *
	 * @param  array $options Field options.
	 * @param  bool  $js      Whether to return format for jQuery UI.
	 *
	 * @return string
	 */
	public function format_datetime( $options, $js = false ) {

		$format = $this->format_date( $options, $js );

		$type = pods_v( static::$type . '_type', $options, 'format' );

		if ( 'format' !== $type || 'c' !== pods_v( static::$type . '_format', $options, '' ) ) {
			$format .= ' ' . $this->format_time( $options, $js );
		}

		return $format;
	}

	/**
	 * Build date format string based on options
	 *
	 * @since 2.7.0
	 *
	 * @param  array $options Field options.
	 * @param  bool  $js      Whether to return format for jQuery UI.
	 *
	 * @return string
	 */
	public function format_date( $options, $js = false ) {

		switch ( (string) pods_v( static::$type . '_type', $options, 'format', true ) ) {
			case 'wp':
				$format = get_option( 'date_format' );

				if ( $js ) {
					$format = $this->convert_format( $format, array( 'source' => 'php', 'type' => 'date' ) );
				}

				break;
			case 'custom':
				if ( ! $js ) {
					$format = pods_v( static::$type . '_format_custom', $options, '' );
				} else {
					$format = pods_v( static::$type . '_format_custom_js', $options, '' );

					if ( empty( $format ) ) {
						$format = pods_v( static::$type . '_format_custom', $options, '' );

						if ( $js ) {
							$format = $this->convert_format( $format, array( 'source' => 'php', 'type' => 'date' ) );
						}
					}
				}

				break;
			default:
				$date_format = $this->get_date_formats( $js );

				$format      = $date_format[ pods_v( static::$type . '_format', $options, 'ymd_dash', true ) ];

				break;
		}//end switch

		return $format;
	}

	/**
	 * Build time format string based on options
	 *
	 * @since 2.7.0
	 *
	 * @param  array $options Field options.
	 * @param  bool  $js      Whether to return format for jQuery UI.
	 *
	 * @return string
	 */
	public function format_time( $options, $js = false ) {

		switch ( (string) pods_v( static::$type . '_time_type', $options, '12', true ) ) {
			case '12':
				$time_format = $this->get_time_formats( $js );

				$format = $time_format[ pods_v( static::$type . '_time_format', $options, 'hh_mm', true ) ];

				break;
			case '24':
				$time_format_24 = $this->get_time_formats_24( $js );

				$format = $time_format_24[ pods_v( static::$type . '_time_format_24', $options, 'hh_mm', true ) ];

				break;
			case 'custom':
				if ( ! $js ) {
					$format = pods_v( static::$type . '_time_format_custom', $options, '' );
				} else {
					$format = pods_v( static::$type . '_time_format_custom_js', $options, '' );
					$js     = false; // Already in JS format.

					if ( empty( $format ) ) {
						$format = pods_v( static::$type . '_time_format_custom', $options, '' );
						$js     = true;
					}
				}

				break;
			default:
				$format = get_option( 'time_format' );

				break;
		}//end switch

		return $format;
	}

	/**
	 * Get the date formats.
	 *
	 * @since 2.7.0
	 *
	 * @param  bool $js Whether to return format for jQuery UI.
	 *
	 * @return array
	 */
	public function get_date_formats( $js = false ) {

		$date_format = array(
			'mdy'       => 'm/d/Y',
			'mdy_dash'  => 'm-d-Y',
			'mdy_dot'   => 'm.d.Y',
			'dmy'       => 'd/m/Y',
			'dmy_dash'  => 'd-m-Y',
			'dmy_dot'   => 'd.m.Y',
			'ymd_slash' => 'Y/m/d',
			'ymd_dash'  => 'Y-m-d',
			'ymd_dot'   => 'Y.m.d',
			'dMy'       => 'd/M/Y',
			'dMy_dash'  => 'd-M-Y',
			'fjy'       => 'F j, Y',
			'fjsy'      => 'F jS, Y',
			'y'         => 'Y',
			'c'         => 'c',
		);

		$filter = 'pods_form_ui_field_date_formats';

		if ( $js ) {
			foreach ( $date_format as $key => $value ) {
				$date_format[ $key ] = $this->convert_format( $value, array( 'type' => 'date' ) );
			}

			$filter = 'pods_form_ui_field_date_js_formats';
		}

		return apply_filters( $filter, $date_format );
	}

	/**
	 * Get the time formats.
	 *
	 * @since 2.7.0
	 *
	 * @param  bool $js Whether to return format for jQuery UI.
	 *
	 * @return array
	 */
	public function get_time_formats( $js = false ) {

		$time_format = array(
			'h_mm_A'     => 'g:i A',
			'h_mm_ss_A'  => 'g:i:s A',
			'hh_mm_A'    => 'h:i A',
			'hh_mm_ss_A' => 'h:i:s A',
			'h_mma'      => 'g:ia',
			'hh_mma'     => 'h:ia',
			'h_mm'       => 'g:i',
			'h_mm_ss'    => 'g:i:s',
			'hh_mm'      => 'h:i',
			'hh_mm_ss'   => 'h:i:s',
		);

		$filter = 'pods_form_ui_field_time_formats';

		if ( $js ) {
			foreach ( $time_format as $key => $value ) {
				$time_format[ $key ] = $this->convert_format( $value, array( 'type' => 'time' ) );
			}

			$filter = 'pods_form_ui_field_time_js_formats';
		}

		return apply_filters( $filter, $time_format );
	}

	/**
	 * Get the time formats.
	 *
	 * @since 2.7.0
	 *
	 * @param  bool $js Whether to return format for jQuery UI.
	 *
	 * @return array
	 */
	public function get_time_formats_24( $js = false ) {

		$time_format_24 = array(
			'hh_mm'    => 'H:i',
			'hh_mm_ss' => 'H:i:s',
		);

		$filter = 'pods_form_ui_field_time_formats_24';

		if ( $js ) {
			foreach ( $time_format_24 as $key => $value ) {
				$time_format_24[ $key ] = $this->convert_format( $value, array( 'type' => 'time' ) );
			}

			$filter         = 'pods_form_ui_field_time_js_formats_24';
		}

		return apply_filters( $filter, $time_format_24 );
	}

	/**
	 * PHP backwards compatibility for createFromFormat.
	 *
	 * @param string  $format           Format string.
	 * @param string  $date             Defaults to time() if empty.
	 * @param boolean $return_timestamp Whether to return the strtotime() or createFromFormat result or not.
	 *
	 * @return DateTime|null|int|false
	 */
	public function createFromFormat( $format, $date, $return_timestamp = false ) {

		$datetime = null;

		try {
			if ( method_exists( 'DateTime', 'createFromFormat' ) ) {

				$datetime = DateTime::createFromFormat( $format, (string) $date );

				if ( false === $datetime ) {
					$datetime = DateTime::createFromFormat( static::$storage_format, (string) $date );
				}

				if ( false !== $datetime && $return_timestamp ) {
					return $datetime;
				}

			}//end if

			if ( in_array( $datetime, array( null, false ), true ) ) {
				if ( empty( $date ) ) {
					$timestamp = time();
				} else {
					$timestamp = strtotime( (string) $date );

					if ( $return_timestamp ) {
						return $timestamp;
					}
				}

				if ( $timestamp ) {
					$datetime = new DateTime( date_i18n( static::$storage_format, $timestamp ) );
				}
			}
		} catch ( Exception $e ) {
			// There is no saving this time value, it's an exception to the rule.
		}

		return apply_filters( 'pods_form_ui_field_datetime_formatter', $datetime, $format, $date );
	}

	/**
	 * Check if a value is compatible with the storage format.
	 *
	 * Valid:
	 * - 0000-00-00 00:00:00
	 * - 0000-00-00 00:00
	 * - 0000-00-00
	 * - 0000-00
	 * - etc.
	 *
	 * @param  string $value The date value.
	 * @return bool
	 */
	public function is_storage_format( $value ) {
		$value_parts  = str_split( $value );
		$format_parts = str_split( gmdate( static::$storage_format ) );

		$valid = true;
		foreach ( $value_parts as $i => $part ) {
			if ( isset( $format_parts[ $i ] ) ) {
				if ( is_numeric( $format_parts[ $i ] ) ) {
					if ( ! is_numeric( $part ) ) {
						$valid = false;
						break;
					}
				} elseif ( $format_parts[ $i ] !== $part ) {
					$valid = false;
					break;
				}
			}
		}
		return $valid;
	}

	/**
	 * Convert a date from one format to another.
	 *
	 * @param string       $value            Field value.
	 * @param string       $new_format       New format string.
	 * @param string|array $original_format  Original format string(s) (if known).
	 * @param boolean      $return_timestamp Whether to return the strtotime() or createFromFormat result or not.
	 *
	 * @return string|int|boolean|DateTime
	 */
	public function convert_date( $value, $new_format, $original_format = '', $return_timestamp = false ) {

		if ( empty( $original_format ) ) {
			$original_format = static::$storage_format;
		}

		if ( is_array( $original_format ) ) {
			foreach ( $original_format as $original_format_option ) {
				$value = $this->convert_date( $value, $new_format, $original_format_option, $return_timestamp );

				if ( false !== $value ) {
					return $value;
				}
			}

			return false;
		}

		$date = '';

		if ( ! $this->is_empty( $value ) ) {
			$date = $this->createFromFormat( $original_format, (string) $value, $return_timestamp );

			if ( $date instanceof DateTime ) {
				$value = $date->format( $new_format );
			} elseif ( false !== $date ) {
				$date = strtotime( (string) $value );

				$value = date_i18n( $new_format, $date );
			}
		} else {
			$value = date_i18n( $new_format );
		}

		// Return timestamp conversion result instead
		if ( $return_timestamp ) {
			return $date;
		}

		return $value;
	}

	/**
	 * Matches each symbol of PHP date format standard with jQuery equivalent codeword.
	 *
	 * @link   http://stackoverflow.com/questions/16702398/convert-a-php-date-format-to-a-jqueryui-datepicker-date-format
	 * @link   https://api.jqueryui.com/datepicker/
	 * @link   http://trentrichardson.com/examples/timepicker/
	 *
	 * @since 2.7.0
	 *
	 * @param  string $source_format Source format string.
	 * @param  array  $args          Format arguments.
	 *
	 * @return string
	 */
	public function convert_format( $source_format, $args = array() ) {

		// @todo Improve source/target logic.
		$args = array_merge(
			array(
				'source' => 'php',
				'type'   => 'date',
			// 'jquery_ui' for reverse.
			), $args
		);

		// Keep keys and values sorted by string length.
		if ( 'time' === $args['type'] || 'time' === static::$type ) {

			$symbols = array(
				// AM/PM.
				'a' => 'tt',
				'A' => 'TT',
				// Swatch internet time (not supported).
				'B' => '',
				// Hour.
				'h' => 'hh',
				'H' => 'HH',
				'g' => 'h',
				'G' => 'H',
				// Minute.
				'i' => 'mm',
				// Second.
				's' => 'ss',
				// Microsecond.
				'u' => 'c',
				// Timezone.
				'O' => 'z',
				'P' => 'Z',
			);

			if ( version_compare( PHP_VERSION, '7.0.0' ) >= 0 ) {
				// Millisecond.
				$symbols['v'] = 'l';
			}

		} else {

			$symbols = array(
				// Day.
				'd' => 'dd',
				'l' => 'DD',
				'D' => 'D',
				'j' => 'd',
				'N' => '',
				'S' => '',
				'w' => '',
				'z' => 'o',
				// Week.
				'W' => '',
				// Month.
				'F' => 'MM',
				'm' => 'mm',
				'M' => 'M',
				'n' => 'm',
				't' => '',
				// Year.
				'L' => '',
				'o' => '',
				'Y' => 'yy',
				'y' => 'y',
			);
		}

		if ( 'jquery_ui' === $args['source'] ) {
			// Remove empty values.
			$symbols = array_filter( $symbols );
			$symbols = array_flip( $symbols );
		}

		$new_format = '';
		$escaping   = false;

		$source_format_length = strlen( $source_format );

		for ( $i = 0; $i < $source_format_length; $i ++ ) {
			$char = $source_format[ $i ];

			// PHP date format escaping character
			// @todo Do we want to support non-format characters?
			if ( '\\' === $char ) {
				$i ++;

				if ( $escaping ) {
					$new_format .= $source_format[ $i ];
				} else {
					$new_format .= '\'' . $source_format[ $i ];
				}

				$escaping = true;
			} else {
				if ( $escaping ) {
					$new_format .= "'";
					$escaping    = false;
				}

				$symbol_key = false;

				if ( isset( $source_format[ $i + 1 ] ) ) {
					$symbol_key = $char . $source_format[ $i + 1 ];
				}

				// Support 2 characters.
				if ( $symbol_key && isset( $symbols[ $symbol_key ] ) ) {
					$new_format .= $symbols[ $symbol_key ];

					$i ++;
				} elseif ( isset( $symbols[ $char ] ) ) {
					$new_format .= $symbols[ $char ];
				} else {
					$new_format .= $char;
				}
			}//end if
		}//end for

		return $new_format;
	}

	/**
	 * Prepare the date/datetime/time field object or options for MomentJS formatting.
	 *
	 * @since 2.8.11
	 *
	 * @param array|Field $options The field object or options.
	 *
	 * @return array|Field The field object or options.
	 */
	public function prepare_options_for_moment_js( $options ) {
		// Handle time formats for datetime.
		if ( 'datetime' === static::$type ) {
			$date_format = $this->get_format_from_options_for_type( $options, static::$type, '', true );
			$time_format = $this->get_format_from_options_for_type( $options, static::$type, '_time', true );

			$date_format_moment_js = $this->convert_format_to_moment_js( $date_format['format'], [
				'source' => $date_format['is_js'] ? 'jquery_ui' : 'php',
				'type'   => 'date',
			] );
			$time_format_moment_js = $this->convert_format_to_moment_js( $time_format['format'], [
				'source' => $time_format['is_js'] ? 'jquery_ui' : 'php',
				'type'   => 'time',
			] );

			$options[ static::$type . '_date_format_moment_js' ] = $date_format_moment_js;
			$options[ static::$type . '_time_format_moment_js' ] = $time_format_moment_js;
		} elseif ( 'date' === static::$type ) {
			$date_format = $this->get_format_from_options_for_type( $options, static::$type, '', true );

			$date_format_moment_js = $this->convert_format_to_moment_js( $date_format['format'], [
				'source' => $date_format['is_js'] ? 'jquery_ui' : 'php',
				'type'   => 'date',
			] );

			$options[ static::$type . '_format_moment_js' ] = $date_format_moment_js;
		} elseif ( 'time' === static::$type ) {
			$time_format = $this->get_format_from_options_for_type( $options, static::$type, '', true );

			$time_format_moment_js = $this->convert_format_to_moment_js( $time_format['format'], [
				'source' => $time_format['is_js'] ? 'jquery_ui' : 'php',
				'type'   => 'time',
			] );

			$options[ static::$type . '_format_moment_js' ] = $time_format_moment_js;
		}

		return $options;
	}

	/**
	 * Get the format from the options for a specific type (date/datetime/time).
	 *
	 * @since 2.8.11
	 *
	 * @param array|Field $options The field object or options.
	 * @param string      $type    The specific field type.
	 * @param string      $prefix  The prefix to use on the format options if needed (like "_time" in datetime_time_format).
	 * @param bool        $js      Whether we want to get the format in the JS context.
	 *
	 * @return array The format information including if found/using the JS context option and the format.
	 */
	public function get_format_from_options_for_type( $options, $type, $prefix = '', $js = false ) {
		$format_type = pods_v( $type . $prefix . '_type', $options );

		$is_date_format = (
			'date' === $type
			|| (
				'datetime' === $type
				&& '' === $prefix
			)
		);

		$is_24_hour = '24' === $format_type;

		if ( '12' === $format_type || $is_24_hour ) {
			$format_type = 'format';
		}

		// Get the format from the field setting.
		if ( 'format' === $format_type ) {
			if ( $is_date_format ) {
				// Get the format for date.
				$formats = $this->get_date_formats();
			} elseif ( $is_24_hour ) {
				// Get the format for time (24-hour).
				$formats = $this->get_time_formats_24();
			} else {
				// Get the format for time (12-hour).
				$formats = $this->get_time_formats();
			}

			$format = pods_v( $type . $prefix . '_format', $options );

			// Get 24-hour format.
			if ( $is_24_hour ) {
				$format = pods_v( $type . $prefix . '_format_24', $options );
			}

			// Check if format is registered.
			if ( ! empty( $formats[ $format ] ) ) {
				return [
					'is_js'  => false,
					'format' => $formats[ $format ],
				];
			}
		}

		// Get the custom format from the field setting.
		if ( 'custom' === $format_type ) {
			$format_custom = pods_v( $type . $prefix . '_format_custom', $options );

			$is_js = false;

			if ( $js ) {
				$format_custom_js = pods_v( $type . $prefix . '_format_custom_js', $options );

				if ( ! empty( $format_custom_js ) ) {
					$is_js = true;

					$format_custom = $format_custom_js;
				}
			}

			// Check if there's a custom format.
			if ( ! empty( $format_custom ) ) {
				return [
					'is_js'  => $is_js,
					'format' => $format_custom,
				];
			}
		}

		// Fallback to wp format.
		$options[ $type . $prefix . '_type' ] = 'wp';

		// Maybe get the date format from WordPress.
		if ( $is_date_format ) {
			return [
				'is_js'  => false,
				'format' => get_option( 'date_format' ),
			];
		}

		// Get the time format from WordPress.
		return [
			'is_js'  => false,
			'format' => get_option( 'time_format' ),
		];
	}

	/**
	 * Convert the source format to MomentJS format for PHP / jQuery UI formats.
	 *
	 * @since 2.8.11
	 *
	 * @param string|mixed $source_format The source format.
	 * @param array        $args          The list of format arguments including source (php/jquery_ui) and type (date/time).
	 *
	 * @return string|mixed The converted MomentJS format.
	 */
	public function convert_format_to_moment_js( $source_format, $args = array() ) {
		if ( ! is_string( $source_format ) || '' === trim( $source_format ) ) {
			return $source_format;
		}

		$defaults = [
			'source' => 'php', // php or jquery_ui.
			'type'   => 'date', // date or time.
		];

		$args = array_merge( $defaults, $args );

		// For PHP symbols, see https://www.php.net/manual/en/datetime.format.php
		// For Moment.js symbols, see https://momentjs.com/docs/#/displaying/format/
		$php_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',
		];

		// For jQuery symbols, see https://api.jqueryui.com/datepicker/#utility-formatDate
		// For Moment.js symbols, see https://momentjs.com/docs/#/displaying/format/
		$jquery_ui_date_replacements = [
			'dd' => 'DD', // day of month (two digit)
			'd'  => 'D', // day of month (no leading zero)
			'oo' => 'DDDD', // day of the year (three digit)
			'o'  => 'DDD', // day of the year (no leading zeros)
			'DD' => 'dddd', // day name long
			'D'  => 'dd', // day name short
			'mm' => 'MM', // month of year (two digit)
			'm'  => 'M', // month of year (no leading zero)
			'MM' => 'MMMM', // month name long
			'M'  => 'MMM', // month name short
			'yy' => 'YYYY', // year (four digit)
			'y'  => 'YY', // year (two digit)
			'@'  => 'X', // Unix timestamp (ms since 01/01/1970)
			'!'  => '', // Windows ticks (100ns since 01/01/0001), no equivalent
		];

		// For jQuery symbols, see http://trentrichardson.com/examples/timepicker/#tp-formatting
		// For Moment.js symbols, see https://momentjs.com/docs/#/displaying/format/
		$jquery_ui_time_replacements = [
			'HH' => 'HH', // Hour with leading 0 (24 hour)
			'H'  => 'H', // Hour with no leading 0 (24 hour)
			'hh' => 'hh', // Hour with leading 0 (12 hour)
			'h'  => 'h', // Hour with no leading 0 (12 hour)
			'mm' => 'mm', // Minute with leading 0
			'm'  => 'm', // Minute with no leading 0
			'i'  => 'mm', // In case they got confused with PHP time format
			'ss' => 'ss', // Second with leading 0
			's'  => 's', // Second with no leading 0
			'l'  => 'SSS', // Milliseconds always with leading 0
			'c'  => 'SSSSSS', // Microseconds always with leading 0
			't'  => 'a', // a or p for AM/PM, no equivalent, switches to am/pm
			'TT' => 'A', // AM or PM for AM/PM
			'tt' => 'a', // am or pm for AM/PM
			'T'  => 'A', // A or P for AM/PM, no equivalent, switches to AM/PM
			'z'  => '', // Timezone as defined by timezoneList => moment().zone();
			'Z'  => '', // Timezone in Iso 8601 format (+04:45) => moment().zone();
		];

		// Handle PHP first since it only has one replacement logic.
		if ( 'php' === $args['source'] ) {
			return pods_replace_keys_to_values( $source_format, $php_replacements );
		}

		// Handle jQuery UI replacements.
		if ( 'jquery_ui' === $args['source'] ) {
			if ( 'date' === $args['type'] ) {
				return pods_replace_keys_to_values( $source_format, $jquery_ui_date_replacements );
			} elseif ( 'time' === $args['type'] ) {
				return pods_replace_keys_to_values( $source_format, $jquery_ui_time_replacements );
			}
		}

		return $source_format;
	}

	/**
	 * Enqueue the i18n files for jquery date/timepicker
	 *
	 * @deprecated since 2.8.0
	 *
	 * @since 2.7.0
	 */
	public function enqueue_jquery_ui_i18n() {
		$done = (array) pods_static_cache_get( 'done', __METHOD__ );

		$types = array();

		switch ( static::$type ) {
			case 'time':
				$types['time'] = true;

				break;
			case 'date':
				$types['date'] = true;

				break;
			case 'datetime':
				$types['time'] = true;
				$types['date'] = true;

				break;
		}

		$locale = str_replace( '_', '-', get_locale() );

		if ( isset( $types['date'] ) && ! isset( $done[ 'date-' . $locale ] ) ) {
			if ( function_exists( 'wp_localize_jquery_ui_datepicker' ) ) {
				wp_localize_jquery_ui_datepicker();
			}

			$done['date'] = true;
		}

		if ( isset( $types['time'] ) && ! isset( $done[ 'time-' . $locale ] ) ) {
			$locale_exists = file_exists( PODS_DIR . 'ui/js/timepicker/i18n/jquery-ui-timepicker-' . $locale . '.js' );

			// Local files.
			if ( ! $locale_exists ) {
				// Fallback to the base language (non-region specific).
				$locale = substr( $locale, 0, strpos( $locale, '-' ) );

				$locale_exists = file_exists( PODS_DIR . 'ui/js/timepicker/i18n/jquery-ui-timepicker-' . $locale . '.js' );
			}

			if ( $locale_exists && ! wp_script_is( 'jquery-ui-timepicker-i18n-' . $locale ) ) {
				wp_enqueue_script( 'jquery-ui-timepicker-i18n-' . $locale, PODS_URL . 'ui/js/timepicker/i18n/jquery-ui-timepicker-' . $locale . '.js', [ 'jquery-ui-timepicker' ], '1.6.3' );
			}

			$done[ 'time-' . $locale ] = true;
		}
	}
}