<?php

namespace App\Services;

use Illuminate\Support\Facades\Http;
use RuntimeException;

/**
 * Minimal client for ClickHouse's HTTP interface — used instead of a
 * ClickHouse composer package to avoid an extra dependency for what's just
 * "POST a query, get JSONEachRow back". Queries are parameterized via
 * ClickHouse's own {name:Type} placeholders (sent as param_name=value query
 * params), never string-concatenated, so this is safe against injection.
 */
class ClickHouseClient
{
    public function __construct(
        private readonly string $baseUrl,
        private readonly string $database,
        private readonly string $username,
        private readonly string $password,
    ) {}

    /**
     * @param  array<string, scalar>  $params  Bound to {name:Type} placeholders in $sql.
     * @return array<int, array<string, mixed>>
     */
    public function query(string $sql, array $params = []): array
    {
        $query = array_merge(
            ['database' => $this->database, 'default_format' => 'JSONEachRow'],
            collect($params)->mapWithKeys(fn ($value, $key) => ["param_{$key}" => $value])->all(),
        );

        $response = Http::withBasicAuth($this->username, $this->password)
            ->withBody($sql, 'text/plain')
            ->post("{$this->baseUrl}/?".http_build_query($query));

        if ($response->failed()) {
            throw new RuntimeException("ClickHouse query failed ({$response->status()}): {$response->body()}");
        }

        // JSONEachRow: one JSON object per line, not a JSON array.
        return collect(explode("\n", trim($response->body())))
            ->filter(fn (string $line) => $line !== '')
            ->map(fn (string $line) => json_decode($line, true))
            ->all();
    }
}