<?php
/**
 * SMS rules: one private post per "when this event happens, send this text".
 *
 * @package Smsportal
 */

namespace Smsportal;

defined( 'ABSPATH' ) || exit;

/**
 * Storage of rules in the non-public post type smsportal_rule. The editor UI lives in wp-admin.
 */
class Rules {

	const POST_TYPE = 'smsportal_rule';

	const DEFAULT_EXPIRES_HOURS = 12;

	/**
	 * Reminders: hours before the appointment.
	 */
	const DEFAULT_HOURS_BEFORE = 24;

	const RECIPIENT_TYPES = array( 'customer', 'fixed' );

	/**
	 * Upper bound of expires_hours and hours_before (one week).
	 */
	const MAX_HOURS = 168;

	const META_PREFIX = 'smsportal_';

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public static function register(): void {
		add_action( 'init', array( self::class, 'register_post_type' ) );
	}

	/**
	 * Register the private post type; only administrators (manage_options) can touch it.
	 *
	 * @return void
	 */
	public static function register_post_type(): void {
		register_post_type(
			self::POST_TYPE,
			array(
				'labels'              => array(
					'name'          => __( 'SMS rules', '85pl-android-sms-api' ),
					'singular_name' => __( 'SMS rule', '85pl-android-sms-api' ),
				),
				'public'              => false,
				'show_ui'             => false,
				'show_in_menu'        => false,
				'show_in_rest'        => false,
				'exclude_from_search' => true,
				'publicly_queryable'  => false,
				'rewrite'             => false,
				'query_var'           => false,
				'supports'            => array( 'title' ),
				'capability_type'     => array( 'smsportal_rule', 'smsportal_rules' ),
				'map_meta_cap'        => false,
				'capabilities'        => array(
					'edit_post'              => 'manage_options',
					'read_post'              => 'manage_options',
					'delete_post'            => 'manage_options',
					'edit_posts'             => 'manage_options',
					'edit_others_posts'      => 'manage_options',
					'delete_posts'           => 'manage_options',
					'publish_posts'          => 'manage_options',
					'read_private_posts'     => 'manage_options',
					'delete_private_posts'   => 'manage_options',
					'delete_published_posts' => 'manage_options',
					'delete_others_posts'    => 'manage_options',
					'edit_private_posts'     => 'manage_options',
					'edit_published_posts'   => 'manage_options',
					'create_posts'           => 'manage_options',
				),
			)
		);
	}

	/**
	 * Create or update a rule.
	 *
	 * @param array<string,mixed> $data Rule fields (event_id, recipient_type, fixed_phone, phone_field, template,
	 *                                  expires_hours, hours_before, enabled).
	 * @param int                 $id   Existing rule ID, or 0 to create.
	 * @return int|\WP_Error Rule ID, or an error (also when $id is not an existing rule).
	 */
	public static function save( array $data, int $id = 0 ) {
		if ( $id > 0 && ( ! get_post( $id ) || self::POST_TYPE !== get_post_type( $id ) ) ) {
			return new \WP_Error( 'smsportal_no_rule', __( 'This rule does not exist.', '85pl-android-sms-api' ) );
		}
		$rule    = self::sanitize( $data );
		$post_id = wp_insert_post(
			array(
				'ID'          => $id,
				'post_type'   => self::POST_TYPE,
				'post_status' => 'publish',
				'post_title'  => $rule['event_id'],
			)
		);
		if ( ! is_int( $post_id ) || $post_id <= 0 ) {
			return new \WP_Error( 'smsportal_rule_not_saved', __( 'The rule could not be saved.', '85pl-android-sms-api' ) );
		}
		foreach ( $rule as $key => $value ) {
			update_post_meta( $post_id, self::META_PREFIX . $key, wp_slash( is_bool( $value ) ? (int) $value : $value ) );
		}
		return $post_id;
	}

	/**
	 * One rule.
	 *
	 * @param int $id Rule ID.
	 * @return array<string,mixed>|null
	 */
	public static function get( int $id ): ?array {
		$post = get_post( $id );
		if ( ! $post || self::POST_TYPE !== $post->post_type ) {
			return null;
		}
		$meta = array();
		foreach ( array( 'event_id', 'recipient_type', 'fixed_phone', 'phone_field', 'template', 'expires_hours', 'hours_before', 'enabled' ) as $key ) {
			$meta[ $key ] = get_post_meta( $id, self::META_PREFIX . $key, true );
		}
		return array_merge( array( 'id' => $id ), self::sanitize( $meta ) );
	}

	/**
	 * All rules, oldest first.
	 *
	 * @return array<int,array<string,mixed>>
	 */
	public static function all(): array {
		$ids = get_posts(
			array(
				'post_type'   => self::POST_TYPE,
				'post_status' => 'publish',
				'numberposts' => -1,
				'fields'      => 'ids',
				'orderby'     => 'ID',
				'order'       => 'ASC',
			)
		);
		$rules = array();
		foreach ( $ids as $id ) {
			$rule = self::get( (int) $id );
			if ( null !== $rule ) {
				$rules[] = $rule;
			}
		}
		return $rules;
	}

	/**
	 * Delete a rule.
	 *
	 * @param int $id Rule ID.
	 * @return bool False when it is not a rule.
	 */
	public static function delete( int $id ): bool {
		if ( $id <= 0 || self::POST_TYPE !== get_post_type( $id ) ) {
			return false;
		}
		return wp_delete_post( $id, true ) instanceof \WP_Post;
	}

	/**
	 * Enabled rules of an event.
	 *
	 * @param string $event_id Event ID.
	 * @return array<int,array<string,mixed>>
	 */
	public static function enabled_for_event( string $event_id ): array {
		$ids = get_posts(
			array(
				'post_type'        => self::POST_TYPE,
				'post_status'      => 'publish',
				'numberposts'      => -1,
				'fields'           => 'ids',
				'orderby'          => 'ID',
				'order'            => 'ASC',
				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query -- few rules, filtered by event.
				'meta_query'       => array(
					array(
						'key'   => self::META_PREFIX . 'event_id',
						'value' => $event_id,
					),
				),
			)
		);
		$rules = array();
		foreach ( $ids as $id ) {
			$rule = self::get( (int) $id );
			if ( null !== $rule && $rule['enabled'] ) {
				$rules[] = $rule;
			}
		}
		return $rules;
	}

	/**
	 * Clean rule fields and fill the defaults.
	 *
	 * phone_field: form field holding the customer's number (Contact Form 7 rules with recipient "customer").
	 * hours_before: how long before the appointment a reminder goes out (reminder events).
	 *
	 * @param array<string,mixed> $data Raw fields.
	 * @return array<string,mixed>
	 */
	private static function sanitize( array $data ): array {
		$type    = (string) ( $data['recipient_type'] ?? 'customer' );
		$hours   = $data['expires_hours'] ?? self::DEFAULT_EXPIRES_HOURS;
		$before  = $data['hours_before'] ?? '';
		$enabled = $data['enabled'] ?? true;
		return array(
			'event_id'       => sanitize_text_field( (string) ( $data['event_id'] ?? '' ) ),
			'recipient_type' => in_array( $type, self::RECIPIENT_TYPES, true ) ? $type : 'customer',
			'fixed_phone'    => sanitize_text_field( (string) ( $data['fixed_phone'] ?? '' ) ),
			'phone_field'    => sanitize_text_field( (string) ( $data['phone_field'] ?? '' ) ),
			'template'       => self::clean_template( is_scalar( $data['template'] ?? '' ) ? (string) ( $data['template'] ?? '' ) : '' ),
			'expires_hours'  => '' === $hours ? self::DEFAULT_EXPIRES_HOURS : self::hours( $hours ),
			'hours_before'   => '' === $before || self::hours( $before ) < 1 ? self::DEFAULT_HOURS_BEFORE : self::hours( $before ),
			'enabled'        => ! in_array( $enabled, array( false, 0, '0', '' ), true ),
		);
	}

	/**
	 * SMS text as plain text: valid UTF-8, line breaks as "\n", no other control characters, trimmed.
	 * Markup characters stay as typed (an SMS is not HTML); screens escape it when printing.
	 *
	 * @param string $template Text.
	 * @return string
	 */
	public static function clean_template( string $template ): string {
		$text = str_replace( array( "\r\n", "\r" ), "\n", wp_check_invalid_utf8( $template, true ) );
		$text = (string) preg_replace( '/[\x00-\x09\x0B-\x1F\x7F]/u', '', $text );
		return trim( $text );
	}

	/**
	 * Whole hours between 0 and MAX_HOURS.
	 *
	 * @param mixed $value Hours.
	 * @return int
	 */
	private static function hours( $value ): int {
		return max( 0, min( self::MAX_HOURS, (int) ( is_scalar( $value ) ? $value : 0 ) ) );
	}
}