<?php

namespace RoosterLMS\Invitations;

use RoosterLMS\Consent\OffersConsent;
use RoosterLMS\Consent\Suppressions;
use RoosterLMS\Core\Clock;
use RoosterLMS\Data\Db;
use RoosterLMS\Data\SqlPart;
use RoosterLMS\I18n\Language;

defined( 'ABSPATH' ) || exit;

final class ChannelInvitees {

	public static function ensure( Invitation $inv, string $email, InviteeSource $source, array $person, string $expiry ): ?array {
		global $wpdb;
		$email = Tokens::address( $email );
		if ( '' === $email || $inv->id <= 0 ) {
			return null;
		}
		$hash  = Tokens::email_hash( $email );
		$now   = Clock::now();
		$first = mb_substr( trim( sanitize_text_field( (string) ( $person['first_name'] ?? '' ) ) ), 0, 100 );
		$last  = mb_substr( trim( sanitize_text_field( (string) ( $person['last_name'] ?? '' ) ) ), 0, 100 );
		$lang  = mb_substr( Language::normalize( (string) ( $person['lang'] ?? '' ) ), 0, 12 );

		$added = Db::query(
			SqlPart::of(
				"INSERT IGNORE INTO %i (invitation_id, user_id, email_hash, email, first_name, last_name, lang, source, token_expires_at, sent_version, state, sent_at, created_at) SELECT %d, COALESCE( acc.ID, 0 ), %s, IF( acc.ID IS NULL, %s, '' ), IF( acc.ID IS NULL, %s, '' ), IF( acc.ID IS NULL, %s, '' ), LEFT( COALESCE( NULLIF( p.lang, '' ), %s ), 12 ), %d, %s, %d, %d, %s, %s FROM ( SELECT 1 AS one ) o LEFT JOIN ( SELECT ua.ID FROM %i ua WHERE ua.user_email = %s ORDER BY ua.ID LIMIT 1 ) acc ON 1 = 1 LEFT JOIN %i p ON p.user_id = acc.ID WHERE NOT ",
				Db::table( 'invitees' ),
				$inv->id,
				$hash,
				$email,
				$first,
				$last,
				$lang,
				$source->value,
				$expiry,
				$inv->version,
				InviteeState::SENT->value,
				$now,
				$now,
				$wpdb->users,
				$email,
				Db::table( 'people' )
			)->add( self::blocked_sql( $hash, $email ) )
		);
		if ( $added > 0 ) {
			$id = Db::insert_id();
			if ( $id <= 0 ) {
				return null;
			}
			$seed = Tokens::seed();
			$done = Db::query( 'UPDATE %i SET token_hash = %s, token_seed = %s WHERE id = %d AND token_hash IS NULL', Db::table( 'invitees' ), Tokens::hash( Tokens::for_invitee( $id, $seed ) ), $seed, $id );
			if ( $done <= 0 ) {
				return null;
			}
			return array(
				'id'      => $id,
				'seed'    => $seed,
				'created' => true,
			);
		}

		$row = Db::row(
			SqlPart::of( 'SELECT /* outside-tx */ i.id, i.user_id, i.state, i.token_hash, i.token_seed, COALESCE( p.notify_offers, 0 ) AS offers, ( CASE WHEN ' )->add( self::blocked_sql( $hash, $email ) )->add( SqlPart::of( ' THEN 1 ELSE 0 END ) AS blocked FROM %i i LEFT JOIN %i p ON p.user_id = i.user_id WHERE i.invitation_id = %d AND i.email_hash = %s LIMIT 1', Db::table( 'invitees' ), Db::table( 'people' ), $inv->id, $hash ) )
		);
		if ( null === $row || 1 === (int) $row['blocked'] || OffersConsent::NO->value === (int) $row['offers'] ) {
			return null;
		}
		$id    = (int) $row['id'];
		$seed  = (string) ( $row['token_seed'] ?? '' );
		$token = Tokens::for_invitee( $id, $seed );
		if ( '' !== $token && hash_equals( (string) ( $row['token_hash'] ?? '' ), Tokens::hash( $token ) ) ) {
			return array(
				'id'      => $id,
				'seed'    => $seed,
				'created' => false,
			);
		}
		$seed = Tokens::seed();
		$old  = (string) ( $row['token_hash'] ?? '' );
		$sql  = SqlPart::of( 'UPDATE %i SET token_hash = %s, token_seed = %s, token_expires_at = %s, state = %d, sent_version = %d, sent_at = %s WHERE id = %d AND ', Db::table( 'invitees' ), Tokens::hash( Tokens::for_invitee( $id, $seed ) ), $seed, $expiry, InviteeState::SENT->value, $inv->version, $now, $id );
		$sql = $sql->add( '' === $old ? SqlPart::of( 'token_hash IS NULL' ) : SqlPart::of( 'token_hash = %s', $old ) );
		if ( Db::query( $sql ) <= 0 ) {
			return null;
		}
		return array(
			'id'      => $id,
			'seed'    => $seed,
			'created' => false,
		);
	}

	private static function blocked_sql( string $hash, string $email ): SqlPart {
		global $wpdb;
		return SqlPart::of( '( ' )->add( Suppressions::exists_sql( SqlPart::of( '%s', $hash ) ) )->add( SqlPart::of( ' OR EXISTS ( SELECT 1 FROM %i sx WHERE sx.email_hash = %s AND sx.user_id = 0 AND sx.state = %d )', Db::table( 'invitees' ), $hash, InviteeState::SUPPRESSED->value ) )->add( SqlPart::of( ' OR EXISTS ( SELECT 1 FROM %i ua2 JOIN %i pa ON pa.user_id = ua2.ID WHERE ua2.user_email = %s AND pa.notify_offers = %d ) )', $wpdb->users, Db::table( 'people' ), $email, OffersConsent::NO->value ) );
	}
}