<?php

namespace App\Services\BrentPriceSources;

use App\Services\ApiLogger;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Throwable;

final class FredBrentPriceSource
{
    private const string URL = 'https://api.stlouisfed.org/fred/series/observations';

    public function __construct(private readonly ApiLogger $apiLogger) {}

    /**
     * @return array{date: string, price_usd: float}[]|null
     */
    public function fetch(): ?array
    {
        try {
            $response = $this->apiLogger->send('fred', 'GET', self::URL, fn () => Http::timeout(10)
                ->get(self::URL, [
                    'series_id' => 'DCOILBRENTEU',
                    'api_key' => config('services.fred.api_key'),
                    'sort_order' => 'desc',
                    'limit' => 30,
                    'file_type' => 'json',
                ]));

            if (! $response->successful()) {
                Log::error('FredBrentPriceSource: request failed', ['status' => $response->status()]);

                return null;
            }

            $rows = collect($response->json('observations') ?? [])
                ->filter(fn (array $obs) => $obs['value'] !== '.')
                ->map(fn (array $obs) => [
                    'date' => $obs['date'],
                    'price_usd' => (float) $obs['value'],
                ])
                ->all();

            if ($rows === []) {
                Log::warning('FredBrentPriceSource: no valid observations returned');

                return null;
            }

            return $rows;
        } catch (Throwable $e) {
            Log::error('FredBrentPriceSource: fetch failed', ['error' => $e->getMessage()]);

            return null;
        }
    }
}