<?php
/**
 * Privacy exporter and eraser.
 *
 * @package HostKhata
 */

namespace HostKhata\Domain\Customers;

defined( 'ABSPATH' ) || exit;

use HostKhata\Core\Hookable;
use HostKhata\Database\Repositories\ActivityRepository;
use HostKhata\Database\Repositories\ContactRepository;
use HostKhata\Database\Repositories\CustomerRepository;
use HostKhata\Database\Repositories\NoteRepository;
use WP_Error;

/**
 * Plugs customers into the WordPress personal data export and erasure tools.
 *
 * Erasing anonymises the customer rather than deleting the row, because
 * invoices and payments must stay valid for accounting.
 *
 * @since 0.1.0
 */
final class CustomerPrivacy implements Hookable {

	/**
	 * Customers.
	 *
	 * @var CustomerRepository
	 */
	private $customers;

	/**
	 * Contacts.
	 *
	 * @var ContactRepository
	 */
	private $contacts;

	/**
	 * Notes.
	 *
	 * @var NoteRepository
	 */
	private $notes;

	/**
	 * Activity log.
	 *
	 * @var ActivityRepository
	 */
	private $activity;

	/**
	 * Customer service.
	 *
	 * @var CustomerService
	 */
	private $service;

	/**
	 * Constructor.
	 *
	 * @param CustomerRepository $customers Customers.
	 * @param ContactRepository  $contacts  Contacts.
	 * @param NoteRepository     $notes     Notes.
	 * @param ActivityRepository $activity  Activity log.
	 * @param CustomerService    $service   Customer service.
	 */
	public function __construct(
		CustomerRepository $customers,
		ContactRepository $contacts,
		NoteRepository $notes,
		ActivityRepository $activity,
		CustomerService $service
	) {
		$this->customers = $customers;
		$this->contacts  = $contacts;
		$this->notes     = $notes;
		$this->activity  = $activity;
		$this->service   = $service;
	}

	/**
	 * {@inheritdoc}
	 */
	public function register(): void {
		add_filter( 'wp_privacy_personal_data_exporters', array( $this, 'register_exporter' ) );
		add_filter( 'wp_privacy_personal_data_erasers', array( $this, 'register_eraser' ) );
	}

	/**
	 * Adds the exporter.
	 *
	 * @since 0.1.0
	 *
	 * @param array<string, mixed> $exporters Registered exporters.
	 * @return array<string, mixed>
	 */
	public function register_exporter( $exporters ) {
		$exporters['hostkhata-customer'] = array(
			'exporter_friendly_name' => __( 'HostKhata customer data', 'hostkhata' ),
			'callback'               => array( $this, 'export' ),
		);

		return $exporters;
	}

	/**
	 * Adds the eraser.
	 *
	 * @since 0.1.0
	 *
	 * @param array<string, mixed> $erasers Registered erasers.
	 * @return array<string, mixed>
	 */
	public function register_eraser( $erasers ) {
		$erasers['hostkhata-customer'] = array(
			'eraser_friendly_name' => __( 'HostKhata customer data', 'hostkhata' ),
			'callback'             => array( $this, 'erase' ),
		);

		return $erasers;
	}

	/**
	 * Exports the data held about the person with the given email address.
	 *
	 * @since 0.1.0
	 *
	 * @param string $email Email address.
	 * @return array{data: array<int, array<string, mixed>>, done: bool}
	 */
	public function export( $email ): array {
		$customer = $this->customer_by_email( (string) $email );

		if ( null === $customer ) {
			return array(
				'data' => array(),
				'done' => true,
			);
		}

		$id     = $customer['id'];
		$groups = array();

		$profile = array(
			__( 'Name', 'hostkhata' )           => trim( $customer['first_name'] . ' ' . $customer['last_name'] ),
			__( 'Email', 'hostkhata' )          => $customer['user_email'],
			__( 'Company', 'hostkhata' )        => $customer['company'],
			__( 'Phone', 'hostkhata' )          => $customer['phone'],
			__( 'Address', 'hostkhata' )        => implode( ', ', array_filter( array( $customer['address_1'], $customer['address_2'], $customer['city'], $customer['state'], $customer['postcode'], $customer['country'] ) ) ),
			__( 'Status', 'hostkhata' )         => $customer['status'],
			__( 'Tags', 'hostkhata' )           => implode( ', ', $customer['tags'] ),
			__( 'Customer since', 'hostkhata' ) => $customer['created_at_gmt'] . ' UTC',
		);

		$groups[] = $this->item( 'hostkhata-customer', __( 'Customer profile', 'hostkhata' ), 'customer-' . $id, $profile );

		foreach ( $this->contacts->for_customer( $id ) as $contact ) {
			$groups[] = $this->item(
				'hostkhata-contacts',
				__( 'Customer contacts', 'hostkhata' ),
				'contact-' . $contact['id'],
				array(
					__( 'Name', 'hostkhata' )  => $contact['name'],
					__( 'Email', 'hostkhata' ) => $contact['email'],
					__( 'Phone', 'hostkhata' ) => $contact['phone'],
					__( 'Role', 'hostkhata' )  => $contact['job_role'],
				)
			);
		}

		foreach ( $this->notes->for_customer( $id, 500 ) as $note ) {
			$groups[] = $this->item(
				'hostkhata-notes',
				__( 'Notes about the customer', 'hostkhata' ),
				'note-' . $note['id'],
				array(
					__( 'Note', 'hostkhata' )  => $note['note'],
					__( 'Added', 'hostkhata' ) => $note['created_at_gmt'] . ' UTC',
				)
			);
		}

		foreach ( $this->activity->for_customer( $id, 500 ) as $entry ) {
			$groups[] = $this->item(
				'hostkhata-activity',
				__( 'Account activity', 'hostkhata' ),
				'activity-' . $entry['id'],
				array(
					__( 'Action', 'hostkhata' ) => $entry['action'],
					__( 'Date', 'hostkhata' )   => $entry['created_at_gmt'] . ' UTC',
				)
			);
		}

		return array(
			'data' => $groups,
			'done' => true,
		);
	}

	/**
	 * Erases the data held about the person with the given email address.
	 *
	 * @since 0.1.0
	 *
	 * @param string $email Email address.
	 * @return array{items_removed: bool, items_retained: bool, messages: string[], done: bool}
	 */
	public function erase( $email ): array {
		$result   = array(
			'items_removed'  => false,
			'items_retained' => false,
			'messages'       => array(),
			'done'           => true,
		);
		$customer = $this->customer_by_email( (string) $email );

		if ( null === $customer || CustomerStatus::ANONYMISED === $customer['status'] ) {
			return $result;
		}

		$counts  = $this->customers->related_counts( $customer['id'] );
		$outcome = $this->service->anonymise( $customer['id'] );

		if ( $outcome instanceof WP_Error ) {
			$result['items_retained'] = true;
			$result['messages'][]     = $outcome->get_error_message();

			return $result;
		}

		$result['items_removed'] = true;

		if ( array_sum( $counts ) > 0 ) {
			$result['items_retained'] = true;
			$result['messages'][]     = __( 'Orders, invoices and payments are kept for accounting. They no longer contain personal details.', 'hostkhata' );
		}

		return $result;
	}

	/**
	 * Finds the customer behind an email address.
	 *
	 * @param string $email Email address.
	 * @return array<string, mixed>|null
	 */
	private function customer_by_email( string $email ): ?array {
		$user = get_user_by( 'email', $email );

		return $user ? $this->customers->find_by_user_id( (int) $user->ID ) : null;
	}

	/**
	 * Builds one export item.
	 *
	 * @param string                $group_id    Group id.
	 * @param string                $group_label Group label.
	 * @param string                $item_id     Item id.
	 * @param array<string, string> $values      Name and value pairs.
	 * @return array<string, mixed>
	 */
	private function item( string $group_id, string $group_label, string $item_id, array $values ): array {
		$data = array();

		foreach ( $values as $name => $value ) {
			if ( '' !== (string) $value ) {
				$data[] = array(
					'name'  => $name,
					'value' => (string) $value,
				);
			}
		}

		return array(
			'group_id'    => $group_id,
			'group_label' => $group_label,
			'item_id'     => $item_id,
			'data'        => $data,
		);
	}
}