<?php

namespace App\Services\Agent\OpenAi;

use App\Services\Agent\ProviderException;
use Illuminate\Http\Client\ConnectionException;
use Illuminate\Support\Facades\Http;
use Psr\Http\Message\ResponseInterface;

class OpenAiApiClient
{
    public function __construct(
        private ?string $baseUrl = null,
        private ?string $apiKey = null,
        private ?string $organization = null,
        private ?string $project = null,
        private ?int $timeoutSeconds = null,
        private ?int $connectTimeoutSeconds = null,
    ) {
        $this->baseUrl = $this->baseUrl ?? (string) config('agent.openai.base_url', '');
        $this->apiKey = $this->apiKey ?? (string) config('agent.openai.api_key', '');
        $this->organization = $this->organization ?? (string) config('agent.openai.organization', '');
        $this->project = $this->project ?? (string) config('agent.openai.project', '');
        $this->timeoutSeconds = $this->timeoutSeconds ?? (int) config('agent.provider.timeout_seconds', 30);
        $this->connectTimeoutSeconds = $this->connectTimeoutSeconds ?? (int) config('agent.provider.connect_timeout_seconds', 5);
    }

    /**
     * Opens a streaming response for the Chat Completions endpoint.
     *
     * @param array<string, mixed> $payload
     */
    public function openStream(array $payload): ResponseInterface
    {
        $baseUrl = trim((string) $this->baseUrl);
        $apiKey = trim((string) $this->apiKey);

        if ($baseUrl === '' || $apiKey === '') {
            throw new ProviderException('CONFIG_MISSING', 'Agent provider configuration missing', false);
        }

        $endpoint = rtrim($baseUrl, '/').'/chat/completions';
        $headers = [
            'Authorization' => 'Bearer '.$apiKey,
            'Accept' => 'text/event-stream',
        ];

        if (trim((string) $this->organization) !== '') {
            $headers['OpenAI-Organization'] = (string) $this->organization;
        }

        if (trim((string) $this->project) !== '') {
            $headers['OpenAI-Project'] = (string) $this->project;
        }

        try {
            $response = Http::withHeaders($headers)
                ->connectTimeout($this->connectTimeoutSeconds)
                ->timeout($this->timeoutSeconds)
                ->withOptions(['stream' => true])
                ->post($endpoint, $payload);
        } catch (ConnectionException $exception) {
            throw new ProviderException(
                'CONNECTION_FAILED',
                'Agent provider connection failed',
                true,
                null,
                $exception->getMessage()
            );
        }

        $status = $response->status();

        if ($status < 200 || $status >= 300) {
            $retryable = $status === 429 || $status >= 500;
            throw new ProviderException(
                'HTTP_ERROR',
                'Agent provider failed',
                $retryable,
                $status,
                $response->body()
            );
        }

        return $response->toPsrResponse();
    }
}