<?php

namespace App\Services\Moderation;

use App\Contracts\Moderation\CommentSpamClassifier;
use App\Data\Moderation\CommentSpamClassification;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Http;
use RuntimeException;

final class TogetherCommentSpamClassifier implements CommentSpamClassifier
{
    public function classify(string $content): CommentSpamClassification
    {
        $config = (array) config('comment_spam.ai', []);
        $key = (string) ($config['api_key'] ?? '');
        $model = (string) ($config['model'] ?? '');
        if ($key === '' || $model === '') {
            throw new RuntimeException('Together AI is not configured.');
        }
        if (! in_array($model, (array) ($config['allowed_models'] ?? []), true)) {
            throw new RuntimeException('Unsupported Together AI comment spam model.');
        }

        $started = microtime(true);
        $response = Http::timeout(min(5, max(1, (int) ($config['timeout'] ?? 5))))
            ->withToken($key)
            ->post(rtrim((string) ($config['base_url'] ?? 'https://api.together.xyz/v1'), '/').'/chat/completions', [
                'model' => $model,
                'temperature' => 0,
                'response_format' => ['type' => 'json_object'],
                'messages' => [
                    ['role' => 'system', 'content' => 'Classify the comment as spam or not spam. Return only JSON: {"spam":true|false,"confidence":0.0,"reason":"short explanation"}. Confidence must be a number from 0 to 1. Spam includes advertising, SEO promotion, unsolicited links, scams, and bot-like promotional repetition.'],
                    ['role' => 'user', 'content' => mb_substr($content, 0, (int) ($config['max_input_chars'] ?? 2500))],
                ],
            ]);

        if ($response->failed()) {
            throw new RuntimeException('Together AI request failed with status '.$response->status().'.');
        }

        $message = Arr::get($response->json(), 'choices.0.message.content');
        $decoded = is_string($message) ? json_decode($message, true) : null;
        if (! is_array($decoded) || ! is_bool($decoded['spam'] ?? null)
            || ! is_numeric($decoded['confidence'] ?? null)
            || $decoded['confidence'] < 0 || $decoded['confidence'] > 1
            || ! is_string($decoded['reason'] ?? null)) {
            throw new RuntimeException('Together AI returned invalid moderation JSON.');
        }

        return new CommentSpamClassification(
            $decoded['spam'],
            (float) $decoded['confidence'],
            mb_substr(trim($decoded['reason']), 0, 500),
            'together',
            $model,
            (int) round((microtime(true) - $started) * 1000),
        );
    }
}