<?php

class OpenAIService
{
    private static $apiKey;

    public static function init()
    {
        self::$apiKey = getenv('OPENAI_API_KEY');
    }

    public static function getCompletion($message)
    {
        if (empty(self::$apiKey)) {
            return ['error' => 'OpenAI API key is not configured.'];
        }

        $url = 'https://api.openai.com/v1/chat/completions';

        $data = [
            'model' => 'gpt-3.5-turbo',
            'messages' => [
                ['role' => 'system', 'content' => 'You are a helpful assistant.'],
                ['role' => 'user', 'content' => $message]
            ],
            'max_tokens' => 150
        ];

        $headers = [
            'Content-Type: application/json',
            'Authorization: Bearer ' . self::$apiKey
        ];

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $response = curl_exec($ch);
        $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($error) {
            return ['error' => 'API call failed: ' . $error];
        }

        if ($httpcode !== 200) {
            return ['error' => 'API returned status ' . $httpcode . ': ' . $response];
        }

        $decodedResponse = json_decode($response, true);

        if (isset($decodedResponse['choices'][0]['message']['content'])) {
            return ['reply' => $decodedResponse['choices'][0]['message']['content']];
        } elseif (isset($decodedResponse['error'])) {
            return ['error' => $decodedResponse['error']['message']];
        }

        return ['error' => 'Unexpected API response format.'];
    }
}

OpenAIService::init();