<?php
/**
 * Settings storage, defaults, sanitizing and REST exposure.
 *
 * @package Stayrail
 */

namespace Stayrail;

defined( 'ABSPATH' ) || exit;

/**
 * Class Settings
 */
class Settings {

	const OPTION = 'stayrail_settings';

	/**
	 * Hook registration.
	 */
	public static function init() {
		add_action( 'init', array( __CLASS__, 'register' ) );
	}

	/**
	 * Default settings.
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			'custom_selectors'    => '',
			'margin_top'          => 0,
			'auto_header_offset'  => true,
			'margin_bottom'       => 0,
			'stack_gap'           => 16,
			'stop_selectors'      => '',
			'auto_stop_footer'    => true,
			'devices'             => array(
				'desktop' => true,
				'tablet'  => true,
				'mobile'  => false,
			),
			'tablet_breakpoint'   => 1024,
			'mobile_breakpoint'   => 768,
			'min_viewport_width'  => 0,
			'min_viewport_height' => 0,
			'z_index'             => 99,
		);
	}

	/**
	 * Current settings merged with defaults.
	 *
	 * @return array
	 */
	public static function get() {
		$saved = get_option( self::OPTION, array() );

		if ( ! is_array( $saved ) ) {
			$saved = array();
		}

		$settings            = array_merge( self::defaults(), $saved );
		$settings['devices'] = array_merge( self::defaults()['devices'], (array) $settings['devices'] );

		return $settings;
	}

	/**
	 * Save settings (sanitized).
	 *
	 * @param array $settings Settings to save.
	 *
	 * @return array Saved settings.
	 */
	public static function update( array $settings ) {
		$clean = self::sanitize( $settings );
		update_option( self::OPTION, $clean );

		return $clean;
	}

	/**
	 * Register the option so it can be read and saved via /wp/v2/settings.
	 */
	public static function register() {
		register_setting(
			'stayrail',
			self::OPTION,
			array(
				'type'              => 'object',
				'default'           => self::defaults(),
				'sanitize_callback' => array( __CLASS__, 'sanitize' ),
				'show_in_rest'      => array(
					'schema' => self::schema(),
				),
			)
		);
	}

	/**
	 * REST schema for the settings object.
	 *
	 * @return array
	 */
	public static function schema() {
		return array(
			'type'                 => 'object',
			'additionalProperties' => false,
			'properties'           => array(
				'custom_selectors'    => array( 'type' => 'string' ),
				'margin_top'          => array( 'type' => 'integer' ),
				'auto_header_offset'  => array( 'type' => 'boolean' ),
				'margin_bottom'       => array( 'type' => 'integer' ),
				'stack_gap'           => array( 'type' => 'integer' ),
				'stop_selectors'      => array( 'type' => 'string' ),
				'auto_stop_footer'    => array( 'type' => 'boolean' ),
				'devices'             => array(
					'type'                 => 'object',
					'additionalProperties' => false,
					'properties'           => array(
						'desktop' => array( 'type' => 'boolean' ),
						'tablet'  => array( 'type' => 'boolean' ),
						'mobile'  => array( 'type' => 'boolean' ),
					),
				),
				'tablet_breakpoint'   => array( 'type' => 'integer' ),
				'mobile_breakpoint'   => array( 'type' => 'integer' ),
				'min_viewport_width'  => array( 'type' => 'integer' ),
				'min_viewport_height' => array( 'type' => 'integer' ),
				'z_index'             => array( 'type' => 'integer' ),
			),
		);
	}

	/**
	 * Sanitize a settings array.
	 *
	 * @param mixed $input Raw input.
	 *
	 * @return array
	 */
	public static function sanitize( $input ) {
		$defaults = self::defaults();
		$input    = is_array( $input ) ? $input : array();
		$out      = array();

		$out['custom_selectors'] = self::sanitize_selectors( isset( $input['custom_selectors'] ) ? $input['custom_selectors'] : '' );
		$out['stop_selectors']   = self::sanitize_selectors( isset( $input['stop_selectors'] ) ? $input['stop_selectors'] : '' );

		$ints = array(
			'margin_top'          => array( 0, 1000 ),
			'margin_bottom'       => array( 0, 2000 ),
			'stack_gap'           => array( 0, 500 ),
			'tablet_breakpoint'   => array( 320, 4000 ),
			'mobile_breakpoint'   => array( 240, 4000 ),
			'min_viewport_width'  => array( 0, 4000 ),
			'min_viewport_height' => array( 0, 4000 ),
			'z_index'             => array( 0, 2147483647 ),
		);

		foreach ( $ints as $key => $range ) {
			$value       = isset( $input[ $key ] ) ? (int) $input[ $key ] : (int) $defaults[ $key ];
			$out[ $key ] = max( $range[0], min( $range[1], $value ) );
		}

		if ( $out['mobile_breakpoint'] >= $out['tablet_breakpoint'] ) {
			$out['mobile_breakpoint'] = max( 240, $out['tablet_breakpoint'] - 1 );
		}

		foreach ( array( 'auto_header_offset', 'auto_stop_footer' ) as $key ) {
			$out[ $key ] = isset( $input[ $key ] ) ? rest_sanitize_boolean( $input[ $key ] ) : (bool) $defaults[ $key ];
		}

		$devices        = isset( $input['devices'] ) && is_array( $input['devices'] ) ? $input['devices'] : array();
		$out['devices'] = array();

		foreach ( $defaults['devices'] as $device => $default ) {
			$out['devices'][ $device ] = isset( $devices[ $device ] ) ? rest_sanitize_boolean( $devices[ $device ] ) : (bool) $default;
		}

		return $out;
	}

	/**
	 * Keep one CSS selector per line and strip anything that can't be part of a selector list.
	 *
	 * @param mixed $value Raw textarea value.
	 *
	 * @return string
	 */
	public static function sanitize_selectors( $value ) {
		$value = sanitize_textarea_field( (string) $value );
		$lines = preg_split( '/\r\n|\r|\n/', $value );
		$clean = array();

		foreach ( $lines as $line ) {
			// "{", "}", ";" and "<" never belong in a selector list. ">" is kept: it is the child combinator.
			$line = trim( str_replace( array( '{', '}', ';', '<' ), '', $line ) );

			if ( '' !== $line ) {
				$clean[] = $line;
			}
		}

		return implode( "\n", array_unique( $clean ) );
	}

	/**
	 * Selector textarea value as an array.
	 *
	 * @param string $value Newline-separated selectors.
	 *
	 * @return string[]
	 */
	public static function lines( $value ) {
		return array_values( array_filter( array_map( 'trim', preg_split( '/\r\n|\r|\n/', (string) $value ) ) ) );
	}
}