<?php
/**
 * Numbers that asked not to receive promotional messages.
 *
 * @package Rahkar\WP
 */

declare( strict_types = 1 );

namespace Rahkar\WP\Notifications;

use Rahkar\WP\Database\Schema;
use Rahkar\WP\Support\Events;

defined( 'ABSPATH' ) || exit;

/**
 * The opt-out list ("لغو۱۱").
 *
 * A number on this list gets no promotional message. Order confirmations,
 * login codes and the like still go: opting out of offers is not opting out of
 * the order the customer just placed.
 *
 * The list keeps a blind index and a masked number, never the number itself.
 * That is enough to answer "is this number opted out?" and to show the list to
 * the shop, and it lets the row survive a privacy erasure: keeping it is exactly
 * what stops the same person being messaged again.
 */
final class Optouts {

	public const SOURCES = [ 'sms_reply', 'provider', 'admin' ];

	/**
	 * Is this number on the list?
	 *
	 * @param string $raw Phone number in any form; anything that is not a mobile
	 *                    number (an email address) is never on the list.
	 */
	public static function has( string $raw ): bool {
		$phone = PhoneNumber::parse( $raw );

		if ( null === $phone ) {
			return false;
		}

		global $wpdb;

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Read once per promotional send, in the queue.
		return null !== $wpdb->get_var(
			$wpdb->prepare(
				'SELECT id FROM %i WHERE phone_hash = %s LIMIT 1',
				Schema::table( 'optouts' ),
				SiteKey::phoneHash( $phone->canonical() )
			)
		);
	}

	/**
	 * Put a number on the list.
	 *
	 * @param string $raw    Phone number in any form.
	 * @param string $source One of {@see self::SOURCES}.
	 *
	 * @return bool Whether the number was added; false when invalid or already listed.
	 */
	public static function add( string $raw, string $source ): bool {
		$phone = PhoneNumber::parse( $raw );

		if ( null === $phone || ! in_array( $source, self::SOURCES, true ) ) {
			return false;
		}

		global $wpdb;

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Own table; INSERT IGNORE on the unique hash makes a repeat harmless.
		$added = (int) $wpdb->query(
			$wpdb->prepare(
				'INSERT IGNORE INTO %i (phone_hash, phone_masked, source, created_at) VALUES (%s, %s, %s, %s)',
				Schema::table( 'optouts' ),
				SiteKey::phoneHash( $phone->canonical() ),
				$phone->masked(),
				$source,
				gmdate( 'Y-m-d H:i:s' )
			)
		) > 0;

		if ( $added ) {
			self::report( 'optout.added', $phone, $source );
		}

		return $added;
	}

	/**
	 * Take a number off the list.
	 *
	 * @param string $raw    Phone number in any form.
	 * @param string $source Who asked; one of {@see self::SOURCES}.
	 *
	 * @return bool Whether a row was removed.
	 */
	public static function remove( string $raw, string $source = 'admin' ): bool {
		$phone = PhoneNumber::parse( $raw );

		if ( null === $phone || ! in_array( $source, self::SOURCES, true ) ) {
			return false;
		}

		global $wpdb;

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Own table.
		$removed = (int) $wpdb->query(
			$wpdb->prepare(
				'DELETE FROM %i WHERE phone_hash = %s',
				Schema::table( 'optouts' ),
				SiteKey::phoneHash( $phone->canonical() )
			)
		) > 0;

		if ( $removed ) {
			self::report( 'optout.removed', $phone, $source );
		}

		return $removed;
	}

	/**
	 * A page of the list, newest first.
	 *
	 * @param int    $page   Page number, from 1.
	 * @param int    $per    Rows per page.
	 * @param string $search A phone number to look for; empty for all.
	 *
	 * @return array{rows: list<array{id: int, phone_masked: string, source: string, created_at: string}>, total: int}
	 */
	public static function page( int $page = 1, int $per = 30, string $search = '' ): array {
		global $wpdb;

		$table  = Schema::table( 'optouts' );
		$offset = ( max( 1, $page ) - 1 ) * $per;

		if ( '' !== trim( $search ) ) {
			$phone = PhoneNumber::parse( $search );

			if ( null === $phone ) {
				return [
					'rows'  => [],
					'total' => 0,
				];
			}

			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Admin screen.
			$rows = $wpdb->get_results(
				$wpdb->prepare( 'SELECT id, phone_masked, source, created_at FROM %i WHERE phone_hash = %s', $table, SiteKey::phoneHash( $phone->canonical() ) ),
				ARRAY_A
			);
			$total = count( (array) $rows );
		} else {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Admin screen.
			$rows = $wpdb->get_results(
				$wpdb->prepare( 'SELECT id, phone_masked, source, created_at FROM %i ORDER BY id DESC LIMIT %d OFFSET %d', $table, $per, $offset ),
				ARRAY_A
			);
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Admin screen.
			$total = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i', $table ) );
		}

		$list = [];

		foreach ( (array) $rows as $row ) {
			$list[] = [
				'id'           => (int) $row['id'],
				'phone_masked' => (string) $row['phone_masked'],
				'source'       => (string) $row['source'],
				'created_at'   => (string) $row['created_at'],
			];
		}

		return [
			'rows'  => $list,
			'total' => $total,
		];
	}

	/**
	 * Report a change to the dashboard (EVENTS-v1.md §9).
	 *
	 * @param string      $type   `optout.added` or `optout.removed`.
	 * @param PhoneNumber $phone  The number.
	 * @param string      $source Who asked.
	 */
	private static function report( string $type, PhoneNumber $phone, string $source ): void {
		if ( Events::listening() ) {
			Events::emit(
				$type,
				[
					'phone'   => $phone->canonical(),
					'channel' => 'sms',
					'source'  => $source,
				]
			);
		}
	}
}