<?php
/**
 * AI Company Health Report
 * GET /v1/reports/company-health?company_id=xxx
 * 
 * Generates an AI-powered financial health analysis using invoice data.
 * Returns insights, warnings, and recommendations in Arabic.
 */

use App\Core\Database;
use App\Core\Encryption;
use App\Core\AI;
use App\Middleware\AuthMiddleware;

$decoded = AuthMiddleware::check();
$db = Database::getInstance();

$tenantId  = $decoded['tenant_id'];
$role      = $decoded['role'];
$companyId = $_GET['company_id'] ?? null;

if (!$companyId) {
    json_error('معرّف الشركة مطلوب', 422);
}

// Verify access
$accessQuery = ($role === 'super_admin')
    ? "SELECT id, name, tax_identification_number FROM companies WHERE id = ? AND deleted_at IS NULL"
    : "SELECT id, name, tax_identification_number FROM companies WHERE id = ? AND tenant_id = ? AND deleted_at IS NULL";

$accessParams = ($role === 'super_admin') ? [$companyId] : [$companyId, $tenantId];
$stmt = $db->prepare($accessQuery);
$stmt->execute($accessParams);
$company = $stmt->fetch();

if (!$company) {
    json_error('الشركة غير موجودة أو ليس لديك صلاحية', 404);
}

$companyName = Encryption::decrypt($company['name']) ?: $company['name'];

try {
    // 1. Gather last 3 months of data
    $months = [];
    for ($i = 0; $i < 3; $i++) {
        $m = date('m', strtotime("-{$i} months"));
        $y = date('Y', strtotime("-{$i} months"));
        
        $stmt = $db->prepare("
            SELECT 
                COUNT(*) as total_invoices,
                COALESCE(SUM(grand_total), 0) as revenue,
                COALESCE(SUM(tax_amount), 0) as tax,
                COALESCE(SUM(discount_total), 0) as discounts,
                COALESCE(AVG(grand_total), 0) as avg_invoice,
                SUM(CASE WHEN status = 'submitted' THEN 1 ELSE 0 END) as submitted_count,
                SUM(CASE WHEN status = 'extracted' THEN 1 ELSE 0 END) as pending_count
            FROM invoices
            WHERE company_id = ? AND MONTH(created_at) = ? AND YEAR(created_at) = ?
        ");
        $stmt->execute([$companyId, $m, $y]);
        $data = $stmt->fetch();
        $data['month'] = (int)$m;
        $data['year'] = (int)$y;
        $months[] = $data;
    }

    // 2. Pending invoices count
    $pendingStmt = $db->prepare("SELECT COUNT(*) FROM invoices WHERE company_id = ? AND status = 'extracted'");
    $pendingStmt->execute([$companyId]);
    $pendingCount = (int)$pendingStmt->fetchColumn();

    // 3. Build AI prompt
    $dataJson = json_encode([
        'company_name' => $companyName,
        'tin' => $company['tax_identification_number'],
        'monthly_data' => $months,
        'pending_invoices' => $pendingCount,
    ], JSON_UNESCAPED_UNICODE);

    $prompt = <<<PROMPT
أنت محلل مالي خبير. حلل البيانات التالية لشركة وأعطِ تقريراً مختصراً بالعربية.

البيانات:
{$dataJson}

أعد الرد بصيغة JSON فقط بدون أي نص إضافي:
{
  "health_score": (رقم من 1 إلى 10),
  "health_label": ("ممتاز" أو "جيد" أو "متوسط" أو "يحتاج انتباه"),
  "summary": "ملخص من سطرين عن الحالة المالية",
  "insights": ["ملاحظة 1", "ملاحظة 2", "ملاحظة 3"],
  "warnings": ["تحذير إن وجد"],
  "recommendations": ["توصية 1", "توصية 2"]
}
PROMPT;

    $aiResponse = AI::ask($prompt, $tenantId);

    // Parse AI response
    $report = null;
    if ($aiResponse) {
        // Extract JSON from response
        $cleaned = preg_replace('/```json?\s*|```/', '', $aiResponse);
        $report = json_decode(trim($cleaned), true);
    }

    // Fallback if AI fails
    if (!$report) {
        $currentMonth = $months[0] ?? [];
        $prevMonth = $months[1] ?? [];
        $score = 5;
        
        if (($currentMonth['total_invoices'] ?? 0) > 0) $score += 2;
        if (($currentMonth['submitted_count'] ?? 0) > 0) $score += 1;
        if ($pendingCount === 0) $score += 1;
        if (($currentMonth['revenue'] ?? 0) > ($prevMonth['revenue'] ?? 0)) $score += 1;

        $report = [
            'health_score' => min(10, $score),
            'health_label' => $score >= 8 ? 'ممتاز' : ($score >= 6 ? 'جيد' : 'متوسط'),
            'summary' => 'تقرير مبني على البيانات المتوفرة بدون تحليل AI.',
            'insights' => ['عدد الفواتير: ' . ($currentMonth['total_invoices'] ?? 0)],
            'warnings' => $pendingCount > 0 ? ["يوجد {$pendingCount} فاتورة بانتظار المراجعة"] : [],
            'recommendations' => ['تأكد من إرسال جميع الفواتير المعتمدة لجوفوترا'],
        ];
    }

    json_success([
        'company_id'   => $companyId,
        'company_name' => $companyName,
        'report'       => $report,
        'data'         => [
            'monthly_summary' => $months,
            'pending_count'   => $pendingCount,
        ],
        'generated_at' => date('c'),
    ], 'تقرير صحة الشركة');

} catch (\Exception $e) {
    safe_error($e, 'reports/company-health', 'حدث خطأ في إنشاء التقرير.');
}