<?php
/**
 * Privacy tools: personal data export, erasure and policy text.
 *
 * @package Aslansheed\OTP
 */

namespace Aslansheed\OTP\Security;

use Aslansheed\OTP\Auth\Custom_Fields;
use Aslansheed\OTP\Auth\Identity_Store;
use Aslansheed\OTP\Auth\Register_Fields;
use Aslansheed\OTP\Auth\Two_Factor;
use Aslansheed\OTP\Database\Schema;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Hooks into the WordPress personal data exporter and eraser.
 */
final class Privacy {

	const EXPORT_LIMIT = 500;

	/**
	 * Registers hooks.
	 *
	 * @return void
	 */
	public static function register() {
		add_filter( 'wp_privacy_personal_data_exporters', array( __CLASS__, 'add_exporter' ) );
		add_filter( 'wp_privacy_personal_data_erasers', array( __CLASS__, 'add_eraser' ) );
		add_action( 'admin_init', array( __CLASS__, 'add_policy_text' ) );
	}

	/**
	 * Adds the exporter.
	 *
	 * @param array $exporters Registered exporters.
	 * @return array
	 */
	public static function add_exporter( $exporters ) {
		$exporters['aslansheed-otp'] = array(
			'exporter_friendly_name' => __( 'Aslansheed Login sign-in data', 'aslansheed-login' ),
			'callback'               => array( __CLASS__, 'export' ),
		);

		return $exporters;
	}

	/**
	 * Adds the eraser.
	 *
	 * @param array $erasers Registered erasers.
	 * @return array
	 */
	public static function add_eraser( $erasers ) {
		$erasers['aslansheed-otp'] = array(
			'eraser_friendly_name' => __( 'Aslansheed Login sign-in data', 'aslansheed-login' ),
			'callback'             => array( __CLASS__, 'erase' ),
		);

		return $erasers;
	}

	/**
	 * Exports the linked identities and sign-in events of a user.
	 *
	 * @param string $email Email address of the user.
	 * @return array{data: array, done: bool}
	 */
	public static function export( $email ) {
		global $wpdb;

		$user = get_user_by( 'email', $email );
		$data = array();

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

		foreach ( Identity_Store::all_for_user( (int) $user->ID ) as $identity ) {
			$data[] = array(
				'group_id'    => 'aslansheed-otp-identities',
				'group_label' => __( 'Linked sign-in identities', 'aslansheed-login' ),
				'item_id'     => 'aslansheed-otp-identity-' . (int) $identity->id,
				'data'        => array(
					array(
						'name'  => __( 'Type', 'aslansheed-login' ),
						'value' => (string) $identity->type,
					),
					array(
						'name'  => __( 'Identifier', 'aslansheed-login' ),
						'value' => (string) $identity->identifier,
					),
					array(
						'name'  => __( 'Verified at (UTC)', 'aslansheed-login' ),
						'value' => (string) $identity->verified_at,
					),
				),
			);
		}

		$profile = array();
		$labels  = array(
			'national' => __( 'National ID', 'aslansheed-login' ),
			'postal'   => __( 'Postal code', 'aslansheed-login' ),
			'birth'    => __( 'Birth date', 'aslansheed-login' ),
		);
		$values  = array(
			'national' => Register_Fields::national_id( (int) $user->ID ),
			'postal'   => (string) get_user_meta( $user->ID, Register_Fields::META_POSTAL_CODE, true ),
			'birth'    => (string) get_user_meta( $user->ID, Register_Fields::META_BIRTH_DATE, true ),
		);

		foreach ( Custom_Fields::values( (int) $user->ID ) as $index => $answer ) {
			$labels[ 'custom_' . $index ] = $answer['label'];
			$values[ 'custom_' . $index ] = $answer['value'];
		}

		$labels['twofa'] = __( 'Two-factor authentication (2FA)', 'aslansheed-login' );
		$values['twofa'] = Two_Factor::is_enabled( (int) $user->ID ) ? __( 'On', 'aslansheed-login' ) : '';

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

		if ( $profile ) {
			$data[] = array(
				'group_id'    => 'aslansheed-otp-profile',
				'group_label' => __( 'Registration details', 'aslansheed-login' ),
				'item_id'     => 'aslansheed-otp-profile-' . (int) $user->ID,
				'data'        => $profile,
			);
		}

		$table = Schema::table( 'audit_log' );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,PluginCheck.Security.DirectDB.UnescapedDBParameter -- Custom table; trusted table name.
		$events = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$table} WHERE user_id = %d ORDER BY id DESC LIMIT %d", (int) $user->ID, self::EXPORT_LIMIT ) );

		foreach ( (array) $events as $event ) {
			$data[] = array(
				'group_id'    => 'aslansheed-otp-events',
				'group_label' => __( 'Sign-in events', 'aslansheed-login' ),
				'item_id'     => 'aslansheed-otp-event-' . (int) $event->id,
				'data'        => array(
					array(
						'name'  => __( 'Event', 'aslansheed-login' ),
						'value' => (string) $event->event,
					),
					array(
						'name'  => __( 'IP address', 'aslansheed-login' ),
						'value' => (string) $event->ip,
					),
					array(
						'name'  => __( 'Time (UTC)', 'aslansheed-login' ),
						'value' => (string) $event->created_at,
					),
				),
			);
		}

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

	/**
	 * Erases the identities of a user and anonymizes their audit entries.
	 *
	 * @param string $email Email address of the user.
	 * @return array{items_removed: int, items_retained: bool, messages: array, done: bool}
	 */
	public static function erase( $email ) {
		global $wpdb;

		$result = array(
			'items_removed'  => 0,
			'items_retained' => false,
			'messages'       => array(),
			'done'           => true,
		);
		$user   = get_user_by( 'email', $email );

		if ( ! $user ) {
			return $result;
		}

		$result['items_removed'] += count( Identity_Store::all_for_user( (int) $user->ID ) );
		Identity_Store::delete_for_user( (int) $user->ID );

		foreach ( array( Register_Fields::META_NATIONAL_ID, Register_Fields::META_NATIONAL_ID_INDEX, Register_Fields::META_POSTAL_CODE, Register_Fields::META_BIRTH_DATE, Two_Factor::META_SECRET, Two_Factor::META_ENABLED, Two_Factor::META_LAST_STEP, Two_Factor::META_RECOVERY, Two_Factor::META_SKIPPED ) as $meta_key ) {
			if ( metadata_exists( 'user', (int) $user->ID, $meta_key ) ) {
				delete_user_meta( (int) $user->ID, $meta_key );
				++$result['items_removed'];
			}
		}

		// Answers stored under the plugin's own prefix go; keys the owner chose, such as billing fields, belong to other plugins' erasers.
		foreach ( Custom_Fields::stored_keys( (int) $user->ID ) as $meta_key ) {
			if ( metadata_exists( 'user', (int) $user->ID, $meta_key ) ) {
				delete_user_meta( (int) $user->ID, $meta_key );
				++$result['items_removed'];
			}
		}

		$table = Schema::table( 'audit_log' );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.PreparedSQL.InterpolatedNotPrepared,PluginCheck.Security.DirectDB.UnescapedDBParameter -- Custom table; trusted table name.
		$changed = $wpdb->query( $wpdb->prepare( "UPDATE {$table} SET user_id = 0, identifier = '', ip = '', user_agent = '' WHERE user_id = %d", (int) $user->ID ) );

		$result['items_removed'] += (int) $changed;

		return $result;
	}

	/**
	 * Suggests text for the site's privacy policy.
	 *
	 * @return void
	 */
	public static function add_policy_text() {
		if ( ! function_exists( 'wp_add_privacy_policy_content' ) ) {
			return;
		}

		wp_add_privacy_policy_content(
			'Aslansheed Login',
			wp_kses_post(
				'<p class="privacy-policy-tutorial">' . __( 'Suggested text for sites that use Aslansheed Login. Adjust it to the channels you enabled.', 'aslansheed-login' ) . '</p>'
				. '<p>' . __( 'When you sign in or register with your phone number or email, we store that identifier so we can recognise you. We send you a one-time code through the delivery service we use (for example an SMS provider, WhatsApp, Telegram or email), which receives your phone number or email address and the code. We keep a security log with the time, IP address and browser of sign-in events to protect your account. If you use Google sign-in, Google tells us your name and verified email address.', 'aslansheed-login' ) . '</p>'
			)
		);
	}
}