<?php

namespace Komponent\Component\Testquestions\Administrator\Service;

defined('_JEXEC') or die;

use Joomla\CMS\Http\HttpFactory;

class AiService
{
    public static function availableModels(): array
    {
        return [
            'openai' => [
                'gpt-4.1-mini' => 'GPT-4.1 mini (starszy)',
                'gpt-5.6-luna' => 'GPT-5.6 Luna',
                'gpt-5.6-terra' => 'GPT-5.6 Terra',
                'gpt-5.6-sol' => 'GPT-5.6 Sol',
                'gpt-6-luna' => 'GPT-6 Luna',
            ],
            'grok' => [
                'grok-4.7' => 'Grok 4.7',
                'grok-4.20' => 'Grok 4.20 Reasoning',
                'grok-4.20-non-reasoning' => 'Grok 4.20 Non-Reasoning',
            ],
            'groq' => [
                'openai/gpt-oss-120b' => 'GPT OSS 120B',
                'openai/gpt-oss-20b' => 'GPT OSS 20B',
                'llama-3.3-70b-versatile' => 'Llama 3.3 70B Versatile',
            ],
            'gemini' => [
                'gemini-3.8-flash' => 'Gemini 3.8 Flash',
                'gemini-3.1-pro-preview' => 'Gemini 3.1 Pro (Preview)',
            ],
        ];
    }

    public function evaluate(string $provider, string $apiKey, string $model, string $question, string $answer, string $pattern, int $maxPoints): array
    {
        $provider = strtolower(trim($provider));
        $provider = preg_replace('/[^a-z]/', '', $provider);
        $config = match ($provider) {
            'grok' => ['url' => 'https://api.x.ai/v1/responses'],
            'groq' => ['url' => 'https://api.groq.com/openai/v1/chat/completions'],
            'gemini' => ['url' => 'https://generativelanguage.googleapis.com/v1beta/models/' . rawurlencode($model) . ':generateContent'],
            default => ['url' => 'https://api.openai.com/v1/responses'],
        };

        if (trim($apiKey) === '') {
            throw new \RuntimeException('AI_NOT_CONFIGURED');
        }

        if (!in_array($provider, ['openai', 'grok', 'groq', 'gemini'], true)) {
            throw new \RuntimeException('Nieprawidłowy dostawca AI: ' . $provider);
        }

        if (!isset(self::availableModels()[$provider][$model])) {
            throw new \RuntimeException('Wybrany model AI nie jest obsługiwany.');
        }

        $input = "Oceń odpowiedź ucznia na pytanie otwarte i ustal liczbę uznanych punktów.\n"
            . "Maksymalna liczba punktów za to pytanie: " . max(0, $maxPoints) . ".\n"
            . "Przyznaj liczbę całkowitą od 0 do maksymalnej liczby punktów. Przyznaj punkty proporcjonalnie za poprawne elementy odpowiedzi; pełne punkty za komplet, część punktów za częściową odpowiedź. Nie przekraczaj limitu.\n\n"
            . "Pytanie:\n" . $question . "\n\n"
            . "Wzorzec odpowiedzi:\n" . $pattern . "\n\n"
            . "Odpowiedź ucznia:\n" . ($answer !== '' ? $answer : 'Brak odpowiedzi') . "\n\n"
            . "Zwróć wyłącznie poprawny obiekt JSON w formacie {\"awarded_points\": liczba_całkowita, \"feedback\": \"krótka ocena po polsku\"}. W ocenie opisz poprawne i brakujące elementy. Nie zmieniaj wzorca odpowiedzi.";

        $requestData = match ($provider) {
            'groq' => [
                'model' => $model,
                'messages' => [['role' => 'user', 'content' => $input]],
                'temperature' => 0.1,
            ],
            'gemini' => [
                'contents' => [['parts' => [['text' => $input]]]],
                'generationConfig' => [
                    'maxOutputTokens' => 256,
                    'responseMimeType' => 'application/json',
                    'thinkingConfig' => ['thinkingLevel' => 'low'],
                ],
            ],
            default => [
                'model' => $model,
                'input' => $input,
            ],
        };
        // GPT-5.x reasoning models do not accept a custom temperature.
        if ($provider === 'grok' || ($provider === 'openai' && $model === 'gpt-4.1-mini')) {
            $requestData['temperature'] = 0.1;
        }
        $payload = json_encode($requestData, JSON_UNESCAPED_UNICODE);

        $headers = [
            'Content-Type' => 'application/json',
        ];
        if ($provider === 'gemini') {
            $headers['x-goog-api-key'] = trim($apiKey);
        } else {
            $headers['Authorization'] = 'Bearer ' . trim($apiKey);
        }

        $response = HttpFactory::getHttp()->post(
            $config['url'],
            $payload,
            $headers,
            $provider === 'gemini' ? 25 : 60
        );
        $body = json_decode((string) $response->body, true);

        if ((int) $response->code < 200 || (int) $response->code >= 300) {
            throw new \RuntimeException((string) ($body['error']['message'] ?? ('HTTP ' . (int) $response->code)));
        }

        $text = $this->extractText($body);
        if ($text === '') {
            throw new \RuntimeException('Brak treści odpowiedzi AI.');
        }

        $jsonText = preg_replace('/^```(?:json)?\s*|\s*```$/i', '', trim($text));
        $result = json_decode($jsonText, true);

        if (!is_array($result) || !isset($result['awarded_points']) || !is_numeric($result['awarded_points'])) {
            $start = strpos($jsonText, '{');
            $end = strrpos($jsonText, '}');
            if ($start !== false && $end !== false && $end > $start) {
                $result = json_decode(substr($jsonText, $start, $end - $start + 1), true);
            }
        }

        if (!is_array($result) || !isset($result['awarded_points']) || !is_numeric($result['awarded_points'])) {
            throw new \RuntimeException('AI zwróciło nieprawidłowy format oceny i punktów.');
        }

        $actualModel = (string) ($body['model'] ?? $model);
        $usage = $this->getUsage($body, $provider, $model);
        if ($usage !== null) {
            $usage['model'] = $actualModel;
        }

        return [
            'awarded_points' => min(max(0, $maxPoints), max(0, (int) $result['awarded_points'])),
            'feedback' => trim((string) ($result['feedback'] ?? '')),
            'usage' => $usage,
        ];
    }

    private function getUsage(array $body, string $provider, string $model): ?array
    {
        // Gemini uses camelCase UsageMetadata at the response root; the
        // OpenAI-compatible providers return their counters in `usage`.
        $usage = $body['usageMetadata'] ?? $body['usage'] ?? null;
        if (!is_array($usage)) {
            return null;
        }

        $inputTokens = max(0, (int) ($usage['input_tokens'] ?? $usage['prompt_tokens'] ?? $usage['promptTokenCount'] ?? 0));
        $outputTokens = max(0, (int) ($usage['output_tokens'] ?? $usage['completion_tokens'] ?? (
            (int) ($usage['candidatesTokenCount'] ?? 0) + (int) ($usage['thoughtsTokenCount'] ?? 0)
        )));
        if ((!isset($usage['input_tokens']) && !isset($usage['prompt_tokens']) && !isset($usage['promptTokenCount']))
            || (!isset($usage['output_tokens']) && !isset($usage['completion_tokens']) && !isset($usage['candidatesTokenCount']))) {
            return null;
        }
        $cachedTokens = min($inputTokens, max(0, (int) ($usage['input_tokens_details']['cached_tokens'] ?? $usage['cachedContentTokenCount'] ?? 0)));
        $cost = null;
        $costSource = '';

        if ($provider === 'grok' && isset($usage['cost_in_usd_ticks']) && is_numeric($usage['cost_in_usd_ticks'])) {
            $cost = (float) $usage['cost_in_usd_ticks'] / 10000000000;
            $costSource = 'provider';
        } elseif ($provider === 'openai' && isset($this->openAiRates()[$model])) {
            [$inputRate, $cachedRate, $outputRate, $cacheWriteRate] = $this->openAiRates()[$model];
            $uncachedTokens = $inputTokens - $cachedTokens;
            $cacheWriteTokens = min($uncachedTokens, max(0, (int) ($usage['input_tokens_details']['cache_write_tokens'] ?? 0)));
            $uncachedTokens -= $cacheWriteTokens;
            $cost = ($uncachedTokens * $inputRate + $cachedTokens * $cachedRate + $cacheWriteTokens * $cacheWriteRate + $outputTokens * $outputRate) / 1000000;
            $costSource = 'token_rates';
        }

        return [
            'provider' => $provider,
            'model' => $model,
            'input_tokens' => $inputTokens,
            'output_tokens' => $outputTokens,
            'total_tokens' => (int) ($usage['total_tokens'] ?? $usage['totalTokenCount'] ?? ($inputTokens + $outputTokens)),
            'cached_input_tokens' => $cachedTokens,
            'cost_usd' => $cost,
            'cost_source' => $costSource,
        ];
    }

    private function openAiRates(): array
    {
        return [
            'gpt-4.1-mini' => [0.40, 0.10, 1.60, 0.40],
            'gpt-5.6-luna' => [0.20, 0.02, 1.20, 0.25],
            'gpt-5.6-terra' => [2.00, 0.20, 12.00, 2.50],
            'gpt-5.6-sol' => [4.00, 0.40, 20.00, 5.00],
            'gpt-6-luna' => [0.10, 0.01, 0.50, 0.125],
        ];
    }

    private function extractText(array $body): string
    {
        if (isset($body['candidates'][0]['content']['parts']) && is_array($body['candidates'][0]['content']['parts'])) {
            $parts = [];
            foreach ($body['candidates'][0]['content']['parts'] as $part) {
                if (isset($part['text']) && is_string($part['text'])) {
                    $parts[] = $part['text'];
                }
            }
            return trim(implode("\n", $parts));
        }

        if (isset($body['choices'][0]['message']['content']) && is_string($body['choices'][0]['message']['content'])) {
            return trim($body['choices'][0]['message']['content']);
        }

        if (!empty($body['output_text']) && is_string($body['output_text'])) {
            return trim($body['output_text']);
        }

        $parts = [];
        foreach ((array) ($body['output'] ?? []) as $output) {
            foreach ((array) ($output['content'] ?? []) as $content) {
                if (!empty($content['text']) && is_string($content['text'])) {
                    $parts[] = $content['text'];
                }
            }
        }

        return trim(implode("\n", $parts));
    }
}