<?php

declare(strict_types=1);

namespace TFGraphics\SmartImport\Knowledge;

final class KnowledgeHistory
{
    private array $entries = [];

    public function record(KnowledgeEntry $entry): KnowledgeEntry
    {
        $fingerprint = $entry->getFingerprint();
        $latest = $this->getLatest($fingerprint);

        if ($latest !== null && $latest->getHash() === $entry->getHash()) {
            return $entry->withVersion($latest->getVersion());
        }

        $version = $latest === null
            ? new KnowledgeVersion(1, $entry->getHash(), $entry->getRetrievedAt())
            : $latest->getVersion()->next($entry->getHash(), $entry->getRetrievedAt());
        $versionedEntry = $entry->withVersion($version);
        $this->entries[$fingerprint][] = $versionedEntry;

        return $versionedEntry;
    }

    public function get(string $fingerprint): array
    {
        return $this->entries[$fingerprint] ?? [];
    }

    public function getLatest(string $fingerprint): ?KnowledgeEntry
    {
        $entries = $this->get($fingerprint);

        return $entries === [] ? null : $entries[array_key_last($entries)];
    }

    public function count(string $fingerprint): int
    {
        return count($this->get($fingerprint));
    }
}