<?php

namespace app\service\AdminConsole;

use app\service\Search\OpenSearchClientFactory;
use support\Db;
use Throwable;

class OpenSearchAdminService
{
    public function status(): array
    {
        $config = config('opensearch.default', []);
        $indexName = config('opensearch.indices.chunks', 'proofdb_chunks');

        $status = [
            'config' => [
                'hosts' => $config['hosts'] ?? [],
                'ssl_verify' => (bool) ($config['ssl_verify'] ?? true),
                'index_name' => $indexName,
            ],
            'database' => [
                'archives_total' => (int) Db::table('archives')->count(),
                'chunks_total' => (int) Db::table('chunks')->count(),
                'embedded_chunks' => (int) Db::table('chunks')->where('embedding_status', 3)->count(),
                'indexed_chunks' => (int) Db::table('chunks')->where('search_index_status', 3)->count(),
            ],
            'opensearch' => [
                'reachable' => false,
                'index_exists' => false,
                'cluster_name' => null,
                'health' => null,
                'docs_count' => 0,
                'mapping_fields' => [],
                'error' => null,
            ],
        ];

        try {
            $client = (new OpenSearchClientFactory())->make();
            $health = $client->cluster()->health();
            $status['opensearch']['reachable'] = true;
            $status['opensearch']['cluster_name'] = $health['cluster_name'] ?? null;
            $status['opensearch']['health'] = $health['status'] ?? null;

            $exists = (bool) $client->indices()->exists(['index' => $indexName]);
            $status['opensearch']['index_exists'] = $exists;

            if ($exists) {
                $stats = $client->indices()->stats(['index' => $indexName]);
                $mapping = $client->indices()->getMapping(['index' => $indexName]);
                $status['opensearch']['docs_count'] = (int) (($stats['_all']['primaries']['docs']['count'] ?? 0));
                $status['opensearch']['mapping_fields'] = array_keys($mapping[$indexName]['mappings']['properties'] ?? []);
            }
        } catch (Throwable $exception) {
            $status['opensearch']['error'] = $exception->getMessage();
        }

        return $status;
    }

    public function documents(string $query = '', int $size = 20): array
    {
        $size = min(50, max(1, $size));
        $indexName = config('opensearch.indices.chunks', 'proofdb_chunks');
        $client = (new OpenSearchClientFactory())->make();

        if (!(bool) $client->indices()->exists(['index' => $indexName])) {
            return [
                'index_name' => $indexName,
                'items' => [],
                'total' => 0,
            ];
        }

        $body = [
            '_source' => [
                'includes' => [
                    'chunk_uid',
                    'archive_uid',
                    'chunk_index',
                    'page_start',
                    'page_end',
                    'title',
                    'summary',
                    'source',
                    'author',
                    'year',
                    'series',
                    'tags',
                    'text',
                    'embedding_model',
                    'embedding_dimensions',
                    'created_time',
                    'updated_time',
                ],
            ],
            'size' => $size,
            'sort' => [
                ['updated_time' => ['order' => 'desc']],
            ],
        ];

        $query = trim($query);
        if ($query === '') {
            $body['query'] = ['match_all' => (object) []];
        } else {
            $body['query'] = [
                'multi_match' => [
                    'query' => $query,
                    'fields' => ['text^3', 'title^2', 'summary^2', 'source', 'author', 'tags'],
                    'type' => 'best_fields',
                ],
            ];
        }

        $response = $client->search([
            'index' => $indexName,
            'body' => $body,
        ]);

        $hits = $response['hits']['hits'] ?? [];

        return [
            'index_name' => $indexName,
            'total' => (int) (($response['hits']['total']['value'] ?? 0)),
            'items' => array_map(function (array $hit): array {
                $source = $hit['_source'] ?? [];
                $text = trim((string) ($source['text'] ?? ''));
                return [
                    'score' => $hit['_score'] ?? null,
                    'chunk_uid' => $source['chunk_uid'] ?? ($hit['_id'] ?? null),
                    'archive_uid' => $source['archive_uid'] ?? null,
                    'chunk_index' => $source['chunk_index'] ?? null,
                    'page_start' => $source['page_start'] ?? null,
                    'page_end' => $source['page_end'] ?? null,
                    'title' => $source['title'] ?? null,
                    'summary' => $source['summary'] ?? null,
                    'source' => $source['source'] ?? null,
                    'author' => $source['author'] ?? null,
                    'year' => $source['year'] ?? null,
                    'series' => $source['series'] ?? null,
                    'tags' => $source['tags'] ?? [],
                    'text_preview' => mb_substr($text, 0, 320),
                    'embedding_model' => $source['embedding_model'] ?? null,
                    'embedding_dimensions' => $source['embedding_dimensions'] ?? null,
                    'created_time' => $source['created_time'] ?? null,
                    'updated_time' => $source['updated_time'] ?? null,
                ];
            }, $hits),
        ];
    }
}