<?php
// SPDX-License-Identifier: GPL-3.0-or-later
declare(strict_types=1);

namespace Aiwend\Knowledge;

use Aiwend\Db\Connection;

/**
 * The synchronous half of privacy for index generations: bulk removal of a source's generation copies (versions with a generation id,
 * their chunks and vectors, and the build claims that could still publish one). Three statements, no loop, no embedding, no provider,
 * no queue: callers run it inside the transaction that changes the source, so the copy is gone when the change is visible, and a
 * background job is never the only thing between a deleted or private source and a generation.
 *
 * The single (lexical) index is never touched here. Everything is scoped by site id.
 */
final class GenerationCopies
{
    /** Every generation copy and claim of the source (made private, deleted, erased). @return array{versions:int, chunks:int} */
    public static function removeAll(Connection $db, int $siteId, int $sourceId): array
    {
        $chunks = $db->execute(
            'DELETE FROM {knowledge_chunks} WHERE site_id = ? AND source_id = ? AND version_id IN (SELECT id FROM {knowledge_versions} WHERE site_id = ? AND source_id = ? AND generation_id IS NOT NULL)',
            [$siteId, $sourceId, $siteId, $sourceId]
        );
        $versions = $db->execute('DELETE FROM {knowledge_versions} WHERE site_id = ? AND source_id = ? AND generation_id IS NOT NULL', [$siteId, $sourceId]);
        $db->execute('DELETE FROM {knowledge_claims} WHERE site_id = ? AND source_id = ?', [$siteId, $sourceId]);
        return ['versions' => $versions, 'chunks' => $chunks];
    }

    /**
     * Ready generation copies of the source built from other text than $contentHash (the source's content was just replaced). Versions
     * being built are left alone: their publish checks the content hash inside its own transaction.
     *
     * @return array{versions:int, chunks:int}
     */
    public static function removeOtherContent(Connection $db, int $siteId, int $sourceId, string $contentHash): array
    {
        $chunks = $db->execute(
            "DELETE FROM {knowledge_chunks} WHERE site_id = ? AND source_id = ? AND version_id IN (SELECT id FROM {knowledge_versions} WHERE site_id = ? AND source_id = ? AND generation_id IS NOT NULL AND state = 'ready' AND content_hash <> ?)",
            [$siteId, $sourceId, $siteId, $sourceId, $contentHash]
        );
        $versions = $db->execute(
            "DELETE FROM {knowledge_versions} WHERE site_id = ? AND source_id = ? AND generation_id IS NOT NULL AND state = 'ready' AND content_hash <> ?",
            [$siteId, $sourceId, $contentHash]
        );
        return ['versions' => $versions, 'chunks' => $chunks];
    }
}