<?php
namespace Mince;

use InvalidArgumentException;
use RuntimeException;
use Index\Data\{DbStatementCache,IDbConnection};
use Index\Net\IPAddress;
use Index\Serialisation\Base32;
use Ramsey\Uuid\UuidInterface;

class Verifications {
    private IDbConnection $dbConn;
    private DbStatementCache $cache;

    public function __construct(IDbConnection $dbConn) {
        $this->dbConn = $dbConn;
        $this->cache = new DbStatementCache($dbConn);
    }

    public static function generateCode(): string {
        return Base32::encode(random_bytes(6));
    }

    public function prune(): void {
        $this->dbConn->execute('DELETE FROM verifications WHERE verify_created < NOW() - INTERVAL 15 MINUTE');
    }

    public function getVerification(
        ?string $code = null,
        UuidInterface|string|null $uuid = null,
        IPAddress|string|null $remoteAddr = null
    ): VerificationInfo {
        $hasCode = $code !== null;
        $hasUuid = $uuid !== null;
        $hasRemoteAddr = $remoteAddr !== null;

        $values = [];
        $query = 'SELECT verify_code, verify_uuid, verify_name, INET6_NTOA(verify_addr), UNIX_TIMESTAMP(verify_created) FROM verifications';
        if($hasCode) {
            $query .= ' WHERE verify_code = ?';
            $values[] = $code;
        } else {
            $args = 0;

            if($hasUuid) {
                if($uuid instanceof UuidInterface)
                    $uuid = $uuid->getBytes();

                ++$args;
                $query .= ' WHERE verify_uuid = ?';
                $values[] = $uuid;
            }

            if($hasRemoteAddr) {
                if($remoteAddr instanceof IPAddress)
                    $remoteAddr = (string)$remoteAddr;

                $query .= sprintf(' %s verify_addr = INET6_ATON(?)', ++$args > 1 ? 'AND' : 'WHERE');
                $values[] = $remoteAddr;
            }
        }

        if(empty($values))
            throw new InvalidArgumentException('Not enough arguments specified.');

        $args = 0;
        $stmt = $this->cache->get($query);
        foreach($values as $value)
            $stmt->addParameter(++$args, $value);
        $stmt->execute();

        $result = $stmt->getResult();
        if(!$result->next())
            throw new RuntimeException('Verification info not found.');

        return VerificationInfo::fromResult($result);
    }

    public function createVerification(
        UuidInterface|string $uuid,
        string $name,
        IPAddress|string $remoteAddr
    ): string {
        if($uuid instanceof UuidInterface)
            $uuid = $uuid->getBytes();
        if($remoteAddr instanceof IPAddress)
            $remoteAddr = (string)$remoteAddr;

        $code = self::generateCode();

        $stmt = $this->cache->get('REPLACE INTO verifications (verify_code, verify_uuid, verify_name, verify_addr) VALUES (?, ?, ?, INET6_ATON(?))');
        $stmt->addParameter(1, $code);
        $stmt->addParameter(2, $uuid);
        $stmt->addParameter(3, $name);
        $stmt->addParameter(4, $remoteAddr);
        $stmt->execute();

        return $code;
    }

    public function deleteVerification(VerificationInfo|string $code): void {
        if($code instanceof VerificationInfo)
            $code = $code->getCode();

        $stmt = $this->cache->get('DELETE FROM verifications WHERE verify_code = ?');
        $stmt->addParameter(1, $code);
        $stmt->execute();
    }
}