<?php

declare(strict_types=1);

namespace App\Services;

use App\Core\Database;

final class RiskAnalysisService
{
    public function calculateCompanyRiskScore(string $companyId): array
    {
        $db = Database::getInstance();
        $score = 100;
        $factors = [];

        // 1. Rejection Rate
        $stmt = $db->prepare("SELECT status, COUNT(*) as count FROM invoices WHERE company_id = ? GROUP BY status");
        $stmt->execute([$companyId]);
        $stats = $stmt->fetchAll();
        
        $total = 0;
        $rejected = 0;
        foreach ($stats as $stat) {
            $total += $stat['count'];
            if ($stat['status'] === 'rejected' || $stat['status'] === 'validation_failed') {
                $rejected += $stat['count'];
            }
        }

        if ($total > 0) {
            $rejectionRate = $rejected / $total;
            if ($rejectionRate > 0.10) { // More than 10% rejections
                $penalty = min(30, (int)(($rejectionRate - 0.10) * 100));
                $score -= $penalty;
                $factors[] = "نسبة رفض عالية: " . round($rejectionRate * 100, 1) . "% (خصم {$penalty} نقطة)";
            }
        }

        // 2. High Value Cash Invoices
        $stmt = $db->prepare("SELECT COUNT(*) as count FROM invoices WHERE company_id = ? AND invoice_type = 'cash' AND grand_total > 5000");
        $stmt->execute([$companyId]);
        $highValueCash = $stmt->fetch()['count'];

        if ($highValueCash > 0) {
            $penalty = min(20, $highValueCash * 2);
            $score -= $penalty;
            $factors[] = "وجود فواتير نقدية بقيم عالية: {$highValueCash} فاتورة (خصم {$penalty} نقطة)";
        }

        // 3. Late submissions (invoice_date is much older than created_at)
        $stmt = $db->prepare("SELECT COUNT(*) as count FROM invoices WHERE company_id = ? AND DATEDIFF(created_at, invoice_date) > 7");
        $stmt->execute([$companyId]);
        $lateInvoices = $stmt->fetch()['count'];

        if ($lateInvoices > 0) {
            $penalty = min(15, $lateInvoices * 1);
            $score -= $penalty;
            $factors[] = "تأخير في رفع الفواتير: {$lateInvoices} فاتورة متأخرة بأكثر من 7 أيام (خصم {$penalty} نقطة)";
        }

        // Determine Risk Level
        $riskLevel = 'low';
        if ($score < 50) {
            $riskLevel = 'high';
        } elseif ($score < 80) {
            $riskLevel = 'medium';
        }

        return [
            'score' => max(0, $score),
            'level' => $riskLevel,
            'factors' => $factors,
            'calculated_at' => date('Y-m-d H:i:s')
        ];
    }
}