<?php

declare( strict_types=1 );

namespace Senti\Subscription;

use SentiVendor\WPDesk\Init\Binding\Hookable;
use wpdb;

/**
 * Handles WordPress personal data export and erasure for subscriptions.
 */
final class Privacy implements Hookable {

	private const PAGE_SIZE = 50;

	public function __construct(
		private wpdb $wpdb
	) {}

	public function hooks(): void {
		add_filter( 'wp_privacy_personal_data_exporters', [ $this, 'exporters' ] );
		add_filter( 'wp_privacy_personal_data_erasers', [ $this, 'erasers' ] );
	}

	/**
	 * @internal
	 * @param array<string, array<string, mixed>> $exporters
	 * @return array<string, array<string, mixed>>
	 */
	public function exporters( array $exporters ): array {
		$exporters['senti-subscriptions'] = [
			'exporter_friendly_name' => __( 'Senti subscriptions', 'senti-feedback' ),
			'callback'               => [ $this, 'export' ],
		];
		return $exporters;
	}

	/**
	 * @internal
	 * @param array<string, array<string, mixed>> $erasers
	 * @return array<string, array<string, mixed>>
	 */
	public function erasers( array $erasers ): array {
		$erasers['senti-subscriptions'] = [
			'eraser_friendly_name' => __( 'Senti subscriptions', 'senti-feedback' ),
			'callback'             => [ $this, 'erase' ],
		];
		return $erasers;
	}

	/**
	 * @internal
	 * @return array{data: array<int, array<string, mixed>>, done: bool}
	 */
	public function export( string $email, int $page = 1 ): array {
		$rows = $this->rows( $email, max( 0, $page - 1 ) * self::PAGE_SIZE, self::PAGE_SIZE );
		$data = [];
		foreach ( $rows as $row ) {
			$data[] = [
				'group_id'    => 'senti-subscriptions',
				'group_label' => __( 'Senti subscriptions', 'senti-feedback' ),
				'item_id'     => 'senti-subscription-' . $row['id'],
				'data'        => [
					[
						'name'  => __( 'Subscription subject', 'senti-feedback' ),
						'value' => $row['subject_type'] . ':' . $row['subject_id'],
					],
					[
						'name'  => __( 'Subscription state', 'senti-feedback' ),
						'value' => $row['state'],
					],
					[
						'name'  => __( 'Subscribed', 'senti-feedback' ),
						'value' => $row['created_gmt'],
					],
				],
			];
		}
		return [
			'data' => $data,
			'done' => count( $rows ) < self::PAGE_SIZE,
		];
	}

	/**
	 * @internal
	 * @return array{items_removed: bool, items_retained: bool, messages: string[], done: bool}
	 */
	public function erase( string $email, int $page = 1 ): array {
		$query = $this->wpdb->prepare( 'SELECT id FROM %i WHERE email_hash = %s ORDER BY id LIMIT %d', $this->wpdb->prefix . 'senti_subscriptions', $this->email_hash( $email ), self::PAGE_SIZE );
		// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- $query is prepared immediately above.
		$ids = is_string( $query ) ? array_map( 'intval', $this->wpdb->get_col( $query ) ) : [];
		if ( $ids !== [] ) {
			$placeholders        = implode( ',', array_fill( 0, count( $ids ), '%d' ) );
			$notifications_table = "{$this->wpdb->prefix}senti_notifications";
			$subscriptions_table = "{$this->wpdb->prefix}senti_subscriptions";

			// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber
			$notif_delete = $this->wpdb->prepare( "DELETE FROM %i WHERE subscription_id IN ($placeholders)", $notifications_table, ...$ids );
			if ( is_string( $notif_delete ) ) {
				// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
				$this->wpdb->query( $notif_delete );
			}

			// phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.PreparedSQL.NotPrepared, WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber
			$sub_delete = $this->wpdb->prepare( "DELETE FROM %i WHERE id IN ($placeholders)", $subscriptions_table, ...$ids );
			// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
			$removed = is_string( $sub_delete ) ? $this->wpdb->query( $sub_delete ) : false;
		} else {
			$removed = 0;
		}
		$remaining_query = $this->wpdb->prepare( 'SELECT COUNT(*) FROM %i WHERE email_hash = %s', $this->wpdb->prefix . 'senti_subscriptions', $this->email_hash( $email ) );
		// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- $remaining_query is prepared immediately above.
		$remaining = is_string( $remaining_query ) ? (int) $this->wpdb->get_var( $remaining_query ) : 0;
		return [
			'items_removed'  => $removed !== false && $removed > 0,
			'items_retained' => false,
			'messages'       => [],
			'done'           => $remaining === 0,
		];
	}

	/**
	 * @return list<array<string, string>>
	 */
	private function rows( string $email, int $offset, int $limit ): array {
		$query = $this->wpdb->prepare( 'SELECT id, subject_type, subject_id, state, created_gmt FROM %i WHERE email_hash = %s ORDER BY id LIMIT %d OFFSET %d', $this->wpdb->prefix . 'senti_subscriptions', $this->email_hash( $email ), $limit, $offset );
		// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- $query is prepared immediately above.
		return is_string( $query ) ? $this->wpdb->get_results( $query, ARRAY_A ) ?: [] : [];
	}

	private function email_hash( string $email ): string {
		return hash( 'sha256', strtolower( sanitize_email( $email ) ) );
	}
}