<?php

namespace RoosterLMS\Invitations;

use RoosterLMS\Consent\SuppressionSource;
use RoosterLMS\Consent\Suppressions;
use RoosterLMS\Content\ObjectType;
use RoosterLMS\Data\Db;
use RoosterLMS\Data\SqlPart;
use RoosterLMS\Domain\Services;
use RoosterLMS\Privacy\UserTable;

defined( 'ABSPATH' ) || exit;

final class Privacy {

	public const ID = 'rooster-lms-invitations';

	public static function exporters( $exporters ) {
		if ( is_array( $exporters ) ) {
			$exporters[ self::ID ] = array(
				'exporter_friendly_name' => __( 'Rooster LMS: invitations', 'rooster-lms' ),
				'callback'               => array( self::class, 'export' ),
			);
		}
		return $exporters;
	}

	public static function erasers( $erasers ) {
		if ( is_array( $erasers ) ) {
			$erasers[ self::ID ] = array(
				'eraser_friendly_name' => __( 'Rooster LMS: invitations', 'rooster-lms' ),
				'callback'             => array( self::class, 'erase' ),
			);
		}
		return $erasers;
	}

	public static function registry( $tables ) {
		if ( ! is_array( $tables ) ) {
			return $tables;
		}
		$entry = new UserTable(
			'invitees',
			'user_id',
			'invitations',
			__( 'Rooster LMS: invitations', 'rooster-lms' ),
			array(
				'invitation_id' => __( 'Invitation', 'rooster-lms' ),
				'email'         => __( 'E-mail', 'rooster-lms' ),
				'first_name'    => __( 'First name', 'rooster-lms' ),
				'last_name'     => __( 'Last name', 'rooster-lms' ),
				'source'        => __( 'Added from (1 earlier learners, 2 CSV, 3 organisation, 4 newsletter list, 5 external list, 6 by hand, 7 asked to be notified)', 'rooster-lms' ),
				'sent_at'       => __( 'Sent', 'rooster-lms' ),
				'answer'        => __( 'Answer (0 none, 1 yes, 2 no, 3 maybe)', 'rooster-lms' ),
				'answered_at'   => __( 'Answered', 'rooster-lms' ),
				'outcome'       => __( 'Outcome (0 none yet, 1 attended, 2 enrolled, 3 joined the cohort)', 'rooster-lms' ),
				'outcome_at'    => __( 'Outcome recorded', 'rooster-lms' ),
			),
			'id'
		);
		$last  = end( $tables );
		if ( $last instanceof UserTable && 'people' === $last->table ) {
			array_splice( $tables, count( $tables ) - 1, 0, array( $entry ) );
			return $tables;
		}
		$tables[] = $entry;
		return $tables;
	}

	public static function export( $email, $page = 1 ): array {
		$email = strtolower( trim( (string) $email ) );
		if ( '' === $email || (int) $page > 1 ) {
			return array(
				'data' => array(),
				'done' => true,
			);
		}
		$rows  = Db::rows( 'SELECT /* outside-tx */ i.id, i.email, i.first_name, i.last_name, i.lang, i.source, i.sent_at, i.answer, i.answered_at, i.outcome, i.outcome_at, i.created_at, v.course_id, v.unit_id, v.kind, c.name AS cohort_name FROM %i i JOIN %i v ON v.id = i.invitation_id LEFT JOIN %i c ON c.id = v.target_cohort_id WHERE i.email_hash = %s AND i.user_id = 0 ORDER BY i.id LIMIT 500', Db::table( 'invitees' ), Db::table( 'invitations' ), Db::table( 'cohorts' ), Tokens::email_hash( $email ) );
		$items  = array();
		$checks = \RoosterLMS\Attendance\GuestCheckins::of_invitees( array_map( static fn( array $r ): int => (int) $r['id'], $rows ) );
		foreach ( $rows as $row ) {
			$course = (int) $row['course_id'];
			$unit   = (int) $row['unit_id'];
			$title  = $unit > 0 ? (string) ( Services::posts()->titles( ObjectType::UNIT, array( $unit ) )[ $unit ]['title'] ?? '' ) : (string) ( Services::posts()->titles( ObjectType::COURSE, array( $course ) )[ $course ]['title'] ?? '' );
			$title  = '' === $title && $course <= 0 ? (string) ( $row['cohort_name'] ?? '' ) : $title;
			$answer = RsvpAnswer::tryFrom( (int) $row['answer'] ) ?? RsvpAnswer::NONE;
			$source = InviteeSource::tryFrom( (int) $row['source'] );
			if ( InvitationKind::INTEREST->value === (int) $row['kind'] ) {
				$items[] = array(
					'group_id'    => self::ID,
					'group_label' => __( 'Rooster LMS: invitations', 'rooster-lms' ),
					'item_id'     => self::ID . '-' . (int) $row['id'],
					'data'        => array(
						array(
							'name'  => __( 'Asked to be notified about', 'rooster-lms' ),
							'value' => $title,
						),
						array(
							'name'  => __( 'E-mail', 'rooster-lms' ),
							'value' => (string) $row['email'],
						),
						array(
							'name'  => __( 'Confirmed', 'rooster-lms' ),
							'value' => (string) $row['created_at'],
						),
						array(
							'name'  => __( 'Language', 'rooster-lms' ),
							'value' => (string) $row['lang'],
						),
					),
				);
				continue;
			}
			$items[] = array(
				'group_id'    => self::ID,
				'group_label' => __( 'Rooster LMS: invitations', 'rooster-lms' ),
				'item_id'     => self::ID . '-' . (int) $row['id'],
				'data'        => array(
					array(
						'name'  => __( 'Invitation to', 'rooster-lms' ),
						'value' => $title,
					),
					array(
						'name'  => __( 'E-mail', 'rooster-lms' ),
						'value' => (string) $row['email'],
					),
					array(
						'name'  => __( 'First name', 'rooster-lms' ),
						'value' => (string) $row['first_name'],
					),
					array(
						'name'  => __( 'Last name', 'rooster-lms' ),
						'value' => (string) $row['last_name'],
					),
					array(
						'name'  => __( 'Added from', 'rooster-lms' ),
						'value' => null === $source ? '' : $source->label(),
					),
					array(
						'name'  => __( 'Sent', 'rooster-lms' ),
						'value' => (string) ( $row['sent_at'] ?? '' ),
					),
					array(
						'name'  => __( 'Answer', 'rooster-lms' ),
						'value' => $answer->label(),
					),
					array(
						'name'  => __( 'Answered', 'rooster-lms' ),
						'value' => (string) ( $row['answered_at'] ?? '' ),
					),
					array(
						'name'  => __( 'Outcome', 'rooster-lms' ),
						'value' => ( InviteeOutcome::tryFrom( (int) ( $row['outcome'] ?? 0 ) ) ?? InviteeOutcome::NONE )->label(),
					),
					array(
						'name'  => __( 'Outcome recorded', 'rooster-lms' ),
						'value' => (string) ( $row['outcome_at'] ?? '' ),
					),
				),
			);
			foreach ( $checks[ (int) $row['id'] ] ?? array() as $check ) {
				$items[ count( $items ) - 1 ]['data'][] = array(
					'name'  => __( 'Checked in at the door', 'rooster-lms' ),
					/* translators: 1: the check-in time, 2: the start of the date (both UTC). */
					'value' => sprintf( __( '%1$s (the date starting %2$s)', 'rooster-lms' ), $check['checked_in_at'], $check['starts_at'] ),
				);
			}
		}
		return array(
			'data' => $items,
			'done' => true,
		);
	}

	public static function erase( $email, $page = 1 ): array {
		unset( $page );
		$email = strtolower( trim( (string) $email ) );
		$user  = '' === $email ? false : get_user_by( 'email', $email );
		if ( '' !== $email ) {
			self::keep_stop( Tokens::email_hash( $email ) );
		}
		$gone = '' === $email ? 0 : Interest::erase( Tokens::email_hash( $email ), $user instanceof \WP_User ? (int) $user->ID : 0 );
		$n    = '' === $email ? 0 : self::anonymise( Tokens::email_hash( $email ), $user instanceof \WP_User ? (int) $user->ID : 0 );
		if ( $gone > 0 && 0 === $n ) {
			return array(
				'items_removed'  => true,
				'items_retained' => false,
				'messages'       => array(),
				'done'           => true,
			);
		}
		return array(
			'items_removed'  => $n > 0,
			'items_retained' => $n > 0,
			'messages'       => $n > 0 ? array( __( 'Invitations: the address, names and links were removed; the answers stay in the counts without anyone\'s name.', 'rooster-lms' ) ) : array(),
			'done'           => true,
		);
	}

	private static function keep_stop( string $email_hash ): void {
		if ( null !== Db::value( 'SELECT /* outside-tx */ 1 FROM %i WHERE email_hash = %s AND user_id = 0 AND state = %d LIMIT 1', Db::table( 'invitees' ), $email_hash, InviteeState::SUPPRESSED->value ) ) {
			Suppressions::add_hash( $email_hash, SuppressionSource::GUEST_STOP );
		}
	}

	public static function on_user_gone( $user_id ): void {
		if ( (int) $user_id > 0 ) {
			Interest::erase( '', (int) $user_id );
			self::anonymise( '', (int) $user_id );
		}
	}

	public static function anonymise( string $email_hash, int $user_id ): int {
		if ( '' === $email_hash && $user_id <= 0 ) {
			return 0;
		}
		global $wpdb;
		$where = array();
		if ( '' !== $email_hash ) {
			$where[] = SqlPart::of( 'email_hash = %s', $email_hash );
		}
		if ( $user_id > 0 ) {
			$where[] = SqlPart::of( 'user_id = %d', $user_id );
		}
		\RoosterLMS\Attendance\GuestCheckins::delete_where( SqlPart::of( '( i.' )->add( SqlPart::join( ' OR i.', $where ) )->add( ' )' ) );
		$sql = SqlPart::of( "UPDATE %i SET user_id = 0, email = '', first_name = '', last_name = '', lang = '', token_hash = NULL, token_seed = NULL, token_expires_at = NULL, email_hash = SHA2( CONCAT( %s, id ), 256 ) WHERE ", Db::table( 'invitees' ), 'erased:' )->add( '( ' )->add( SqlPart::join( ' OR ', $where ) )->add( ' )' );
		return max( 0, Db::query( $sql ) );
	}
}