<?php

declare(strict_types=1);

namespace App\Modules\AI;

use App\Core\{Request, Response, Database};
use GuzzleHttp\Client;
use Throwable;

final class AIController
{
    private Client $httpClient;
    private string $apiKey;
    private string $model;

    public function __construct()
    {
        $this->httpClient = new Client();
        $this->apiKey = $_ENV['GEMINI_API_KEY'] ?? '';
        $this->model = $_ENV['GEMINI_MODEL'] ?? 'gemini-2.0-flash';
    }

    public function query(Request $request): void
    {
        $userQuery = $request->input('query');
        if (!$userQuery) {
            Response::error('يرجى تقديم استفسار', 'MISSING_QUERY', 422);
            return;
        }

        try {
            // 1. Fetch current context data (Summary of stats)
            $stats = $this->getQuickStats($request->tenantId);

            // 2. Ask Gemini to interpret and answer
            $prompt = "You are Musadaq AI Assistant for a Jordanian E-Invoicing SaaS. " .
                     "The user is asking: \"{$userQuery}\". " .
                     "Current User Context: Tenant ID {$request->tenantId}. " .
                     "Current Data Summary: " . json_encode($stats) . ". " .
                     "Answer the user in a friendly Arabic tone (Jordanian dialect is okay). " .
                     "Keep it professional and concise. If you don't have the specific data, say so politely.";

            $response = $this->httpClient->post("https://generativelanguage.googleapis.com/v1beta/models/{$this->model}:generateContent?key={$this->apiKey}", [
                'json' => [
                    'contents' => [['parts' => [['text' => $prompt]]]]
                ]
            ]);

            $data = json_decode($response->getBody()->getContents(), true);
            $answer = $data['candidates'][0]['content']['parts'][0]['text'] ?? 'عذراً، لم أستطع فهم الاستفسار حالياً.';

            Response::json([
                'success' => true,
                'data' => [
                    'answer' => $answer
                ]
            ]);

        } catch (Throwable $e) {
            Response::error('فشل معالجة الاستعلام الذكي', 'AI_QUERY_FAILED', 500, [
                'error' => $e->getMessage()
            ]);
        }
    }

    private function getQuickStats(string $tenantId): array
    {
        $db = Database::getInstance();
        
        $totalInvoices = $db->prepare("SELECT COUNT(*) as total FROM invoices WHERE tenant_id = ?");
        $totalInvoices->execute([$tenantId]);
        
        $approvedCount = $db->prepare("SELECT COUNT(*) as total FROM invoices WHERE tenant_id = ? AND status = 'approved'");
        $approvedCount->execute([$tenantId]);

        return [
            'total_invoices' => $totalInvoices->fetch()['total'],
            'approved_invoices' => $approvedCount->fetch()['total'],
            'current_month' => date('F Y')
        ];
    }
}