<?php
/**
 * Notes Field
 *
 * @since       1.17
 * @license     GPL2+
 * @package     GravityView
 * @author      Katz Web Services, Inc.
 * @link        https://www.gravitykit.com
 * @copyright   Copyright 2016, Katz Web Services, Inc.
 */

/**
 * Add Entry Notes
 *
 * @since 1.17
 */
class GravityView_Field_Notes extends GravityView_Field {
	const ASSETS_HANDLE = 'gravityview-notes';

	/**
	 * @since 1.17
	 * @var string Current __FILE__
	 */
	public static $file;

	/**
	 * @since 1.17
	 * @var string plugin_dir_path() of the current field file
	 */
	public static $path;

	/**
	 * @since 1.17
	 * @var bool Are we doing an AJAX request?
	 */
	private $doing_ajax = false;

	/**
	 * The name of the GravityView field type
	 *
	 * @var string
	 */
	public $name = 'notes';

	/** @var string $icon Icon class for the field. */
	public $icon = 'dashicons-admin-comments';

	/**
	 * Constructor.
	 */
	public function __construct() {

		self::$path = plugin_dir_path( __FILE__ );
		self::$file = __FILE__;

		$this->doing_ajax = defined( 'DOING_AJAX' ) && DOING_AJAX;

		$this->add_hooks();

		parent::__construct();
	}

	/**
	 * Add AJAX hooks, [gv_note_add] shortcode, and template loading paths
	 *
	 * @since 1.17
	 *
	 * @return void
	 */
	private function add_hooks() {

		add_shortcode( 'gv_note_add', [ 'GravityView_Field_Notes', 'get_add_note_part' ] );

		add_action( 'wp', [ $this, 'maybe_delete_notes' ], 1000 );
		add_action( 'wp_ajax_nopriv_gv_delete_notes', [ $this, 'maybe_delete_notes' ] );
		add_action( 'wp_ajax_gv_delete_notes', [ $this, 'maybe_delete_notes' ] );

		add_action( 'wp', [ $this, 'maybe_add_note' ], 1000 );
		add_action( 'wp_ajax_nopriv_gv_note_add', [ $this, 'maybe_add_note' ] );
		add_action( 'wp_ajax_gv_note_add', [ $this, 'maybe_add_note' ] );

		// add template path to check for field
		add_filter( 'gravityview_template_paths', [ $this, 'add_template_path' ] );
		add_filter( 'gravityview/template/fields_template_paths', [ $this, 'add_template_path' ] );

		add_action( 'gravityview/field/notes/scripts', [ $this, 'enqueue_scripts' ] );

		add_filter( 'gravityview_entry_default_fields', [ $this, 'add_entry_default_field' ], 10, 3 );
	}


	/**
	 * Add Entry Notes to the Add Field picker in Edit View
	 *
	 * @since 1.17
	 *
	 * @see   GravityView_Admin_Views::get_entry_default_fields()
	 *
	 * @param array  $entry_default_fields Fields configured to show in the picker
	 * @param array  $form                 Gravity Forms form array
	 * @param string $zone                 Current context: `directory`, `single`, `edit`
	 *
	 * @return array Fields array with notes added, if in Multiple Entries or Single Entry context
	 */
	public function add_entry_default_field( $entry_default_fields, $form, $zone ) {

		if ( in_array( $zone, [ 'directory', 'single' ] ) ) {
			$entry_default_fields['notes'] = [
				'label' => __( 'Entry Notes', 'gk-gravityview' ),
				'type'  => 'notes',
				'desc'  => __( 'Display, add, and delete notes for an entry.', 'gk-gravityview' ),
				'icon'  => 'dashicons-admin-comments',
			];
		}

		return $entry_default_fields;
	}

	/**
	 * Registers scripts and styles used in the UI.
	 *
	 * @since 1.17
	 *
	 * @return void
	 */
	public function register_scripts() {
		$css_file = gravityview_css_url( 'entry-notes.css', self::$path . 'assets/css/' );

		wp_register_style( self::ASSETS_HANDLE, $css_file, [], GV_PLUGIN_VERSION );
		wp_register_script( self::ASSETS_HANDLE, plugins_url( '/assets/js/entry-notes.js', self::$file ), [ 'jquery' ], GV_PLUGIN_VERSION, true );
	}

	/**
	 * Enqueues and localizes scripts and styles.
	 *
	 * @since 1.17
	 *
	 * @return void
	 */
	public function enqueue_scripts() {
		if ( wp_script_is( self::ASSETS_HANDLE ) ) {
			return;
		}

		if ( ! wp_script_is( self::ASSETS_HANDLE, 'registered' ) ) {
			$this->register_scripts();
		}

		$strings = self::strings();

		wp_localize_script(
			self::ASSETS_HANDLE,
			'GVNotes',
			[
				'ajaxurl' => admin_url( 'admin-ajax.php' ),
				'text'    => [
					'processing'       => $strings['processing'],
					'delete_confirm'   => $strings['delete-confirm'],
					'note_added'       => $strings['added-note'],
					'error_invalid'    => $strings['error-invalid'],
					'error_empty_note' => $strings['error-empty-note'],
				],
			]
		);

		wp_enqueue_style( self::ASSETS_HANDLE );
		wp_enqueue_script( self::ASSETS_HANDLE );
	}

	/**
	 * Verify permissions, check if $_POST is set and as expected. If so, use process_add_note.
	 *
	 * @since 1.17
	 *
	 * @see process_add_note()
	 *
	 * @return void
	 */
	public function maybe_add_note() {
		if ( ! isset( $_POST['action'] ) || 'gv_note_add' !== $_POST['action'] ) {
			return;
		}

		if ( ! GVCommon::has_cap( 'gravityview_add_entry_notes' ) ) {
			gravityview()->log->error( "The user isn't allowed to add entry notes." );

			return;
		}

		$post = wp_unslash( $_POST );

		if ( $this->doing_ajax ) {
			parse_str( $post['data'], $data );
		} else {
			$data = $post;
		}

		// Sanitize fields appropriately based on their expected content
		$sanitized_data = $this->sanitize_note_data( $data );

		$this->process_add_note( (array) $sanitized_data );
	}

	/**
	 * Sanitize note data fields appropriately based on their expected content type.
	 *
	 * @since 1.17
	 *
	 * @param array $data Raw data from $_POST.
	 *
	 * @return array Sanitized data array.
	 */
	private function sanitize_note_data( $data ) {
		$sanitized = [];

		$single_line_text_fields = [
			'entry-slug',
			'gv_note_add',
			'action',
			'add_note',
			'_wp_http_referer',
			'gv-note-to',
			'gv-note-subject',
		];

		foreach ( $single_line_text_fields as $field ) {
			if ( ! isset( $data[ $field ] ) ) {
				continue;
			}

			$sanitized[ $field ] = sanitize_text_field( $data[ $field ] );
		}

		if ( isset( $data['gv-note-content'] ) ) {
			$sanitized['gv-note-content'] = sanitize_textarea_field( $data['gv-note-content'] );
		}

		if ( isset( $data['gv-note-to-custom'] ) ) {
			$sanitized['gv-note-to-custom'] = sanitize_email( $data['gv-note-to-custom'] );
		}

		if ( isset( $data['show-delete'] ) ) {
			$sanitized['show-delete'] = (int) $data['show-delete'];
		}

		foreach ( $data as $key => $value ) {
			if ( ! isset( $sanitized[ $key ] ) ) {
				$sanitized[ $key ] = sanitize_text_field( $value );
			}
		}

		return $sanitized;
	}

	/**
	 * Handle adding a note.
	 *
	 * Verify the request. If valid, add the note. If AJAX request, send response JSON.
	 *
	 * @since 1.17
	 *
	 * @param array $data {
	 *     Array of note data.
	 *
	 *     @type string $action           Action name "gv_note_add".
	 *     @type string $entry-slug       Entry slug or ID to add note to.
	 *     @type string $gv_note_add      Nonce with action "gv_note_add_{entry slug}" and name "gv_note_add".
	 *     @type string $_wp_http_referer Relative URL to submitting page ('/view/example/entry/123/').
	 *     @type string $gv-note-content  Note content.
	 *     @type string $add_note         Submit button value ('Add Note').
	 * }
	 *
	 * @return void
	 */
	private function process_add_note( $data ) {

		if ( empty( $data['entry-slug'] ) ) {

			$error = self::strings( 'error-invalid' );
			gravityview()->log->error( 'The note is missing an Entry ID.' );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( $error ) ] );
			}

			return;
		}

		$valid = wp_verify_nonce( $data['gv_note_add'], 'gv_note_add_' . $data['entry-slug'] );

		$has_cap = GVCommon::has_cap( 'gravityview_add_entry_notes' );

		if ( ! $has_cap ) {
			gravityview()->log->error( 'Adding a note failed: the user does not have the "gravityview_add_entry_notes" capability.' );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-cap-add' ) ) ] );
			}

			return;
		}

		if ( ! $valid ) {
			gravityview()->log->error( 'Nonce validation failed; the note was not created' );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-invalid' ) ) ] );
			}

			return;
		}

		$entry = gravityview_get_entry( $data['entry-slug'], true, false );

		if ( ! $entry ) {
			gravityview()->log->error( 'The entry was not found', [ 'data' => compact( 'data' ) ] );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-invalid' ) ) ] );
			}

			return;
		}

		$added = $this->add_note( $entry, $data );

		// Error adding note
		if ( is_wp_error( $added ) ) {

			gravityview()->log->error( 'Error adding note', [ 'data' => compact( 'added' ) ] );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( $added->get_error_message() ) ] );
			}

			return;
		}

		if ( ! class_exists( 'GFAPI' ) ) {
			gravityview()->log->error( 'GFAPI is not loaded' );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-add-note' ) ) ] );
			}
			return;
		}

		// Confirm the note was added, because GF doesn't return note ID on success.
		$note = GFAPI::get_note( $added );

		if ( is_wp_error( $note ) ) {
			gravityview()->log->error( 'The note was not successfully created', [ 'data' => compact( 'note', 'data' ) ] );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-add-note' ) ) ] );
			}

			return;
		}

		// Possibly email peeps about this great new note.
		$email_success = $this->maybe_send_entry_notes( $note, $entry, $data );

		if ( is_wp_error( $email_success ) ) {
			gravityview()->log->error( 'The note was not successfully emailed', [ 'data' => compact( 'note', 'data' ) ] );

			if ( $this->doing_ajax ) {
				wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-email-note' ) ) ] );
			}
		}

		$success = self::display_note( $note, ! empty( $data['show-delete'] ) );

		gravityview()->log->debug( 'The note was successfully created', [ 'data' => compact( 'note', 'data' ) ] );

		if ( ! $this->doing_ajax ) {
			return;
		}

		if ( $success ) {
			if ( $this->doing_ajax ) {
				wp_send_json_success( [ 'html' => $success ] );
			}
			return;
		}

		if ( $this->doing_ajax ) {
			wp_send_json_error( [ 'error' => esc_html( self::strings( 'error-invalid' ) ) ] );
		}
	}

	/**
	 * Possibly delete notes, if request is proper.
	 *
	 * Verify permissions. Check expected $_POST. Parse args, then send to process_delete_notes.
	 *
	 * @since 1.17
	 *
	 * @see process_delete_notes()
	 *
	 * @return void
	 */
	public function maybe_delete_notes() {

		if ( ! GVCommon::has_cap( 'gravityview_delete_entry_notes' ) ) {
			return;
		}

		if ( isset( $_POST['action'] ) && 'gv_delete_notes' === $_POST['action'] ) {

			$post = wp_unslash( $_POST );
			if ( $this->doing_ajax ) {
				parse_str( $post['data'], $data );
			} else {
				$data = $post;
			}

			$required_args = [
				'gv_delete_notes' => '',
				'entry-slug'      => '',
			];

			$data = wp_parse_args( $data, $required_args );

			// Sanitize the delete data
			$data['gv_delete_notes'] = sanitize_text_field( $data['gv_delete_notes'] );
			$data['entry-slug']      = sanitize_text_field( $data['entry-slug'] );
			if ( isset( $data['note'] ) && is_array( $data['note'] ) ) {
				$data['note'] = array_map( 'absint', $data['note'] );
			}

			$this->process_delete_notes( $data );
		}
	}

	/**
	 * Handle deleting notes.
	 *
	 * @since 1.17
	 *
	 * @param array $data {
	 *     Array of deletion data.
	 *
	 *     @type string $action           Action name "gv_delete_notes".
	 *     @type string $entry-slug       Entry slug or ID to delete notes from.
	 *     @type string $gv_delete_notes  Nonce with action "gv_delete_notes_{entry slug}" and name "gv_delete_notes".
	 *     @type string $_wp_http_referer Relative URL to submitting page ('/view/example/entry/123/').
	 *     @type int[]  $note             Array of Note IDs to be deleted.
	 * }
	 *
	 * @return void
	 */
	public function process_delete_notes( $data ) {

		$valid   = wp_verify_nonce( $data['gv_delete_notes'], 'gv_delete_notes_' . $data['entry-slug'] );
		$has_cap = GVCommon::has_cap( 'gravityview_delete_entry_notes' );
		$success = false;

		if ( $valid && $has_cap ) {
			GravityView_Entry_Notes::delete_notes( $data['note'] );
			$success = true;
		}

		if ( $this->doing_ajax ) {

			if ( $success ) {
				wp_send_json_success();
			} else {
				if ( ! $valid ) {
					$error_message = self::strings( 'error-invalid' );
				} else {
					$error_message = self::strings( 'error-permission-delete' );
				}

				wp_send_json_error( [ 'error' => $error_message ] );
			}
		}
	}

	/**
	 * Include this extension templates path.
	 *
	 * @since 1.17
	 *
	 * @param array $file_paths List of template paths ordered.
	 *
	 * @return array File paths with `./` and `./partials/` paths added.
	 */
	public function add_template_path( $file_paths ) {

		$file_paths[172] = self::$path;
		$file_paths[173] = self::$path . 'partials/';

		return $file_paths;
	}

	public function field_options( $field_options, $template_id, $field_id, $context, $input_type, $form_id ) {

		unset( $field_options['show_as_link'] );

		$notes_options = [
			'notes' => [
				'type'    => 'checkboxes',
				'label'   => __( 'Note Settings', 'gk-gravityview' ),
				'desc'    => sprintf( _x( 'Only users with specific capabilities will be able to view, add and delete notes. %1$sRead more%2$s.', '%s is opening and closing HTML link', 'gk-gravityview' ), '<a href="https://docs.gravitykit.com/article/311-gravityview-capabilities">', '</a>' ),
				'options' => [
					'view'           => [
						'label' => __( 'Display notes?', 'gk-gravityview' ),
					],
					'view_loggedout' => [
						'label'    => __( 'Display notes to users who are not logged-in?', 'gk-gravityview' ),
						'requires' => 'view',
					],
					'add'            => [
						'label' => __( 'Enable adding notes?', 'gk-gravityview' ),
					],
					'email'          => [
						'label'    => __( 'Allow emailing notes?', 'gk-gravityview' ),
						'requires' => 'add',
					],
					'delete'         => [
						'label' => __( 'Allow deleting notes?', 'gk-gravityview' ),
					],
				],
				'value'   => [
					'view'  => 1,
					'add'   => 1,
					'email' => 1,
				],
			],
		];

		return $notes_options + $field_options;
	}

	/**
	 * Get strings used by the Entry Notes field.
	 *
	 * Use `gravityview/field/notes/strings` filter to modify the strings.
	 *
	 * @since 1.17
	 *
	 * @param string $key If set, return the string with the key of $key.
	 *
	 * @return array|string Array of strings with keys and values. If $key is set, returns string. If missing $strings[ $key ], empty string.
	 */
	public static function strings( $key = '' ) {

		$strings = [
			'add-note'              => __( 'Add Note', 'gk-gravityview' ),
			'added-note'            => __( 'Note added.', 'gk-gravityview' ),
			'content-label'         => __( 'Note Content', 'gk-gravityview' ),
			'delete'                => __( 'Delete', 'gk-gravityview' ),
			'delete-confirm'        => __( 'Are you sure you want to delete the selected notes?', 'gk-gravityview' ),
			'caption'               => __( 'Notes for this entry', 'gk-gravityview' ),
			'toggle-notes'          => __( 'Toggle all notes', 'gk-gravityview' ),
			'no-notes'              => __( 'There are no notes.', 'gk-gravityview' ),
			'processing'            => __( 'Processing&hellip;', 'gk-gravityview' ),
			'other-email'           => __( 'Other email address', 'gk-gravityview' ),
			'email-label'           => __( 'Email address', 'gk-gravityview' ),
			'email-placeholder'     => _x( 'you@example.com', 'Example email address used as a placeholder', 'gk-gravityview' ),
			'subject-label'         => __( 'Subject', 'gk-gravityview' ),
			'subject'               => __( 'Email subject', 'gk-gravityview' ),
			'default-email-subject' => __( 'New entry note', 'gk-gravityview' ),
			'email-footer'          => __( 'This note was sent from {url}', 'gk-gravityview' ),
			'also-email'            => __( 'Also email this note to', 'gk-gravityview' ),
			'error-add-note'        => __( 'There was an error adding the note.', 'gk-gravityview' ),
			'error-email-note'      => __( 'There was an error emailing the note.', 'gk-gravityview' ),
			'error-invalid'         => __( 'The request was invalid. Refresh the page and try again.', 'gk-gravityview' ),
			'error-empty-note'      => _x( 'Note cannot be blank.', 'Message to display when submitting a note without content.', 'gk-gravityview' ),
			'error-cap-delete'      => __( 'You don\'t have the ability to delete notes.', 'gk-gravityview' ),
			'error-cap-add'         => __( 'You don\'t have the ability to add notes.', 'gk-gravityview' ),
		];

		/**
		 * Modify the strings used by the Entry Notes field.
		 *
		 * @since 1.17
		 *
		 * @param array $strings Text in key => value pairs
		 */
		$strings = gv_map_deep( apply_filters( 'gravityview/field/notes/strings', $strings ), 'esc_html' );

		if ( $key ) {
			return isset( $strings[ $key ] ) ? $strings[ $key ] : '';
		}

		return $strings;
	}

	/**
	 * Generate HTML output for a single note.
	 *
	 * @since 1.17
	 * @since 2.0
	 *
	 * @param object               $note        Note object with id, user_id, date_created, value, note_type, user_name, user_email vars.
	 * @param bool                 $show_delete Whether to show the bulk delete inputs.
	 * @param \GV\Template_Context $context     The context.
	 *
	 * @return string HTML.
	 */
	public static function display_note( $note, $show_delete = false, $context = null ) {

		if ( ! is_object( $note ) ) {
			return '';
		}

		$note_content = [
			'avatar'                 => get_avatar( $note->user_id, 48 ),
			'user_name'              => esc_html( $note->user_name ),
			'user_email'             => esc_html( $note->user_email ),
			'added_on'               => esc_html__( 'added on {date_created_formatted}', 'gk-gravityview' ),
			'value'                  => wpautop( esc_html( $note->value ) ),
			'date_created'           => esc_html( $note->date_created ),
			'date_created_formatted' => esc_html( GFCommon::format_date( $note->date_created, false ) ),
			'user_id'                => intval( $note->user_id ),
			'note_type'              => esc_html( $note->note_type ),
			'note_id'                => intval( $note->id ),
		];

		/**
		 * Modify the note content before rendering in the template.
		 *
		 * @since 1.17
		 * @since 2.0
		 *
		 * @param object               $note         Note object with id, user_id, date_created, value, note_type, user_name, user_email vars
		 * @param boolean              $show_delete  True: Notes are editable. False: no editing notes.
		 * @param array                $note_content Array of note content that will be replaced in template files
		 * @param \GV\Template_Context $context      The context.
		 */
		$note_content = apply_filters( 'gravityview/field/notes/content', $note_content, $note, $show_delete, $context );

		$note_row_template = ( $show_delete && GVCommon::has_cap( 'gravityview_delete_entry_notes' ) ) ? 'row-editable' : 'row';

		if ( $context instanceof \GV\Template_Context ) {

			ob_start();
			$context->template->get_template_part( 'note', 'detail', true );
			$note_detail_html = ob_get_clean();

			ob_start();
			$context->template->get_template_part( 'note', $note_row_template, true );
			$note_row = ob_get_clean();

		} else {
			/** @deprecated path */
			ob_start();
			GravityView_View::getInstance()->get_template_part( 'note', 'detail' );
			$note_detail_html = ob_get_clean();

			ob_start();
			GravityView_View::getInstance()->get_template_part( 'note', $note_row_template );
			$note_row = ob_get_clean();
		}

		foreach ( $note_content as $tag => $value ) {
			// Ensure value is a string and handle null values safely.
			$replacement = $value !== null ? (string) $value : '';
			// The tag itself should be safe as it comes from our code, not user input.
			$note_detail_html = str_replace( '{' . esc_attr( $tag ) . '}', $replacement, $note_detail_html );
		}

		$replacements = [
			'{note_id}'     => $note_content['note_id'],
			'{row_class}'   => 'gv-note',
			'{note_detail}' => $note_detail_html,
		];

		// Strip extra whitespace in template.
		$output = gravityview_strip_whitespace( $note_row );

		foreach ( $replacements as $tag => $replacement ) {
			$output = str_replace( $tag, $replacement, $output );
		}

		return $output;
	}

	/**
	 * Add a note.
	 *
	 * @since 1.17
	 *
	 * @see GravityView_Entry_Notes::add_note() This method is mostly a wrapper.
	 *
	 * @param array $entry Entry array.
	 * @param array $data  Note details array.
	 *
	 * @return int|WP_Error Note ID on success, WP_Error on failure.
	 */
	private function add_note( $entry, $data ) {
		global $current_user;

		$user_data = get_userdata( $current_user->ID );

		$note_content = trim( $data['gv-note-content'] );

		if ( empty( $note_content ) ) {
			return new WP_Error( 'gv-add-note-empty', __( 'The note is empty.', 'gk-gravityview' ) );
		}

		return GravityView_Entry_Notes::add_note( $entry['id'], $user_data->ID, $user_data->display_name, $note_content, 'gravityview/field/notes' );
	}

	/**
	 * Get the Add Note form HTML.
	 *
	 * @since 1.17
	 * @since 2.0
	 *
	 * @param array                $atts    Shortcode attributes for entry ID.
	 * @param \GV\Template_Context $context The context, when called outside of a shortcode.
	 *
	 * @return string HTML of the Add Note form, or empty string if the user doesn't have the `gravityview_add_entry_notes` cap.
	 */
	public static function get_add_note_part( $atts, $context = null ) {

		$atts = shortcode_atts( [ 'entry' => null ], $atts );

		if ( ! GVCommon::has_cap( 'gravityview_add_entry_notes' ) ) {
			gravityview()->log->error( 'User does not have permission to add entry notes ("gravityview_add_entry_notes").' );

			return '';
		}

		if ( $context instanceof \GV\Template_Context ) {

			ob_start();
			$context->template->get_template_part( 'note', 'add-note', true );
			$add_note_html = ob_get_clean();

			$visibility_settings = $context->field->notes;
			$gv_entry            = $context->entry;
		} else {
			$gravityview_view = GravityView_View::getInstance();

			ob_start();
			$gravityview_view->get_template_part( 'note', 'add-note' );
			$add_note_html = ob_get_clean();

			$visibility_settings = $gravityview_view->getCurrentFieldSetting( 'notes' );

			if ( $atts['entry'] ) {
				$entry = GFAPI::get_entry( $atts['entry'] );
			}

			if ( ! isset( $entry ) || ! $entry ) {
				$entry = $gravityview_view->getCurrentEntry();
			}

			$gv_entry = \GV\GF_Entry::from_entry( $entry );
		}

		// Strip extra whitespace in template.
		$add_note_html = gravityview_strip_whitespace( $add_note_html );
		$entry_slug    = $gv_entry->get_slug();
		$nonce_field   = wp_nonce_field( 'gv_note_add_' . $entry_slug, 'gv_note_add', false, false );

		// Only generate the dropdown if the field settings allow it.
		$email_fields = '';
		if ( ! empty( $visibility_settings['email'] ) ) {
			$email_fields = self::get_note_email_fields( $entry_slug );
		}

		$add_note_html = str_replace( '{entry_slug}', $entry_slug, $add_note_html );
		$add_note_html = str_replace( '{nonce_field}', $nonce_field, $add_note_html );
		$add_note_html = str_replace( '{show_delete}', (string) intval( empty( $visibility_settings['delete'] ) ? 0 : $visibility_settings['delete'] ), $add_note_html );
		$add_note_html = str_replace( '{email_fields}', $email_fields, $add_note_html );
		$add_note_html = str_replace( '{url}', esc_url_raw( add_query_arg( [] ) ), $add_note_html );

		return $add_note_html;
	}

	/**
	 * Get array of emails addresses from the stored entry.
	 *
	 * @since 1.17
	 *
	 * @return array Array of email addresses connected to the entry.
	 */
	private static function get_note_emails_array() {

		$gravityview_view = GravityView_View::getInstance();

		$email_fields = GFCommon::get_email_fields( $gravityview_view->getForm() );

		$entry = $gravityview_view->getCurrentEntry();

		$note_emails = [];

		foreach ( $email_fields as $email_field ) {
			if ( ! empty( $entry[ "{$email_field->id}" ] ) && is_email( $entry[ "{$email_field->id}" ] ) ) {
				$note_emails[] = $entry[ "{$email_field->id}" ];
			}
		}

		/**
		 * Modify the dropdown values displayed in the "Also email note to" dropdown.
		 *
		 * @since 1.17
		 *
		 * @param array $note_emails Array of email addresses connected to the entry.
		 * @param array $entry       Current entry.
		 */
		$note_emails = apply_filters( 'gravityview/field/notes/emails', $note_emails, $entry );

		return (array) $note_emails;
	}

	/**
	 * Generate a HTML dropdown of email values based on email fields from the current form.
	 *
	 * @since 1.17
	 *
	 * @uses get_note_emails_array()
	 *
	 * @param int|string $entry_slug Current entry unique ID.
	 *
	 * @return string HTML output.
	 */
	private static function get_note_email_fields( $entry_slug = '' ) {

		if ( ! GVCommon::has_cap( 'gravityview_email_entry_notes' ) ) {
			gravityview()->log->error( 'User does not have permission to email entry notes ("gravityview_email_entry_notes").' );

			return '';
		}

		$entry_slug_esc = esc_attr( $entry_slug );

		$note_emails = self::get_note_emails_array();

		$strings = self::strings();

		/**
		 * Whether to include a Custom Email option for users to define a custom email to mail notes to.
		 *
		 * @since 1.17
		 *
		 * @param bool $include_custom Default: true.
		 */
		$include_custom = apply_filters( 'gravityview/field/notes/custom-email', true );

		ob_start();

		if ( ! empty( $note_emails ) || $include_custom ) { ?>
			<div class="gv-note-email-container">
				<label for="gv-note-email-to-<?php echo $entry_slug_esc; ?>" class="screen-reader-text"><?php echo $strings['also-email']; ?></label>
				<select class="gv-note-email-to" name="gv-note-to" id="gv-note-email-to-<?php echo $entry_slug_esc; ?>">
					<option value=""><?php echo $strings['also-email']; ?></option>
					<?php
					foreach ( $note_emails as $email ) {
						?>
						<option value="<?php echo esc_attr( $email ); ?>"><?php echo esc_html( $email ); ?></option>
						<?php
					}
					if ( $include_custom ) {
						?>
						<option value="custom"><?php echo self::strings( 'other-email' ); ?></option>
					<?php } ?>
				</select>
				<fieldset class="gv-note-to-container">
					<?php if ( $include_custom ) { ?>
						<div class='gv-note-to-custom-container'>
							<label for="gv-note-email-to-custom-<?php echo $entry_slug_esc; ?>"><?php echo $strings['email-label']; ?></label>
							<input type="text" name="gv-note-to-custom" placeholder="<?php echo $strings['email-placeholder']; ?>" id="gv-note-to-custom-<?php echo $entry_slug_esc; ?>" value="" />
						</div>
					<?php } ?>
					<div class='gv-note-subject-container'>
						<label for="gv-note-subject-<?php echo $entry_slug_esc; ?>"><?php echo $strings['subject-label']; ?></label>
						<input type="text" name="gv-note-subject" placeholder="<?php echo $strings['subject']; ?>" id="gv-note-subject-<?php echo $entry_slug_esc; ?>" value="" />
					</div>
				</fieldset>
			</div>
			<?php
		}

		return ob_get_clean();
	}

	/**
	 * If note has an email to send, and the user has the right caps, send it.
	 *
	 * Note: Tap in to Gravity Forms' `gform_after_email` action if you want a return result from sending the email.
	 *
	 * @since 1.17
	 *
	 * @param false|object $note  If note was created, object. Otherwise, false.
	 * @param array        $entry Entry data.
	 * @param array        $data  $_POST data.
	 *
	 * @return void|false|WP_Error Returns false if email not configured, WP_Error on failure, void on success.
	 */
	private function maybe_send_entry_notes( $note = false, $entry = [], $data = [] ) {

		// Emailing notes is not configured.
		if ( empty( $data['gv-note-to'] ) ) {
			return false;
		}

		// The note is empty.
		if ( ! $note ) {
			return new WP_Error( 'gv-add-note-empty', __( 'The note is empty.', 'gk-gravityview' ) );
		}

		// The user does not have the "gravityview_email_entry_notes" cap.
		if ( ! GVCommon::has_cap( 'gravityview_email_entry_notes' ) ) {
			gravityview()->log->error( 'User doesn\'t have "gravityview_email_entry_notes" cap', [ 'data' => $note ] );
			return new WP_Error( 'gv-email-note-cap', __( 'You do not have permission to email entry notes.', 'gk-gravityview' ) );
		}

		gravityview()->log->debug( '$data', [ 'data' => $data ] );

		$default_data = [
			'gv-note-to'        => '',
			'gv-note-to-custom' => '',
			'gv-note-subject'   => '',
			'gv-note-content'   => '',
			'current-url'       => '',
		];

		$current_user = wp_get_current_user();
		$email_data   = wp_parse_args( $data, $default_data );

		$from = $current_user->user_email;
		$to   = $email_data['gv-note-to'];

		/**
		 * Documented in get_note_email_fields.
		 *
		 * @see get_note_email_fields
		 */
		$include_custom = apply_filters( 'gravityview/field/notes/custom-email', true );

		if ( 'custom' === $to && $include_custom ) {
			$to = $email_data['gv-note-to-custom'];
			gravityview()->log->debug( 'Sending note to a custom email address: {to}', [ 'to' => $to ] );
		}

		if ( ! GFCommon::is_valid_email_list( $to ) ) {
			gravityview()->log->error(
				'$to not a valid email or email list (CSV of emails): {to}',
				[
					'to'   => print_r( $to, true ),
					'data' => $email_data,
				]
			);

			return new WP_Error( 'gv-add-note-invalid-email', __( 'The email address is invalid.', 'gk-gravityview' ) );
		}

		$bcc      = false;
		$reply_to = $from;
		$subject  = trim( $email_data['gv-note-subject'] );

		// We use empty() here because GF uses empty to check against, too. `0` isn't a valid subject to GF
		$subject        = empty( $subject ) ? self::strings( 'default-email-subject' ) : $subject;
		$message        = $email_data['gv-note-content'];
		$email_footer   = self::strings( 'email-footer' );
		$from_name      = $current_user->display_name;
		$message_format = 'html';

		/**
		 * Modify the values passed when sending a note email.
		 *
		 * @since 1.17
		 * @see   GVCommon::send_email
		 *
		 * @param array $email_settings Values being passed to the GVCommon::send_email() method: 'from', 'to', 'bcc', 'reply_to', 'subject', 'message', 'from_name', 'message_format', 'entry', 'email_footer'
		 */
		$email_content = apply_filters( 'gravityview/field/notes/email_content', compact( 'from', 'to', 'bcc', 'reply_to', 'subject', 'message', 'from_name', 'message_format', 'entry', 'email_footer' ) );

		extract( $email_content );

		$is_html = ( 'html' === $message_format );

		// Add the message footer.
		$message .= $this->get_email_footer( $email_footer, $is_html, $email_data );

		/**
		 * Should the message content have paragraphs added automatically, if using HTML message format.
		 *
		 * @since 1.18
		 *
		 * @param bool $wpautop_email True: Apply wpautop() to the email message if using; False: Leave as entered (Default: true).
		 */
		$wpautop_email = apply_filters( 'gravityview/field/notes/wpautop_email', true );

		if ( $is_html && $wpautop_email ) {
			$message = wpautop( $message );
		}

		GVCommon::send_email( $from, $to, $bcc, $reply_to, $subject, $message, $from_name, $message_format, '', $entry, false );

		$form = isset( $entry['form_id'] ) ? GVCommon::get_form( $entry['form_id'] ) : [];

		/**
		 * @see https://www.gravityhelp.com/documentation/article/10146-2/ It's here for compatibility with Gravity Forms.
		 */
		do_action( 'gform_post_send_entry_note', __METHOD__, $to, $from, $subject, $message, $form, $entry );
	}

	/**
	 * Get the footer for Entry Note emails.
	 *
	 * `{url}` is replaced by the URL of the page where the note form was embedded.
	 *
	 * @since 1.18
	 *
	 * @see GravityView_Field_Notes::strings() The default value of $message_footer is set here, with the key 'email-footer'.
	 *
	 * @param string $email_footer The message footer value.
	 * @param bool   $is_html      True: Email is being sent as HTML; False: sent as text.
	 * @param array  $email_data   Email data array.
	 *
	 * @return string If email footer is not empty, return the message with placeholders replaced with dynamic values.
	 */
	private function get_email_footer( $email_footer = '', $is_html = true, $email_data = [] ) {

		$output = '';

		if ( ! empty( $email_footer ) ) {
			$url = \GV\Utils::get( $email_data, 'current-url' );
			$url = html_entity_decode( $url );
			$url = site_url( $url );

			$content = $is_html ? "<a href='{$url}'>{$url}</a>" : $url;

			$email_footer = str_replace( '{url}', $content, $email_footer );

			$output .= "\n\n$email_footer";
		}

		return $output;
	}
}

new GravityView_Field_Notes();
