<?php
/**
 * what_if_simulator.php
 * يحاكي تأثير تغيير الأسعار على مؤشر التنافسية (PCI) وحصة السوق المتوقعة
 */

require_once __DIR__ . '/../../connect.php';

if ($role !== 'admin' && $role !== 'super_admin') {
    http_response_code(403);
    echo json_encode(['status' => 'failure', 'message' => 'Unauthorized']);
    exit;
}

try {
    $countryCode = resolveAdminCountry(filterRequest('country_code'), $role, $admin_country ?? null);
    $proposedSpeedPrice = (float)filterRequest('speed_price');
    
    if (!$countryCode || $proposedSpeedPrice <= 0) {
        jsonError("Missing required parameters: country_code, speed_price");
        exit;
    }

    // 1. Fetch recent competitor trips (last 7 days, limit 500 for fast simulation)
    $sql = "SELECT distance_km, total_price, competitor_name
            FROM competitor_prices 
            WHERE country_code = :country 
              AND distance_km > 0
              AND created_at >= DATE_SUB(NOW(), INTERVAL 7 DAY)
            ORDER BY created_at DESC 
            LIMIT 500";
            
    $stmt = $con->prepare($sql);
    $stmt->execute([':country' => strtoupper($countryCode)]);
    $trips = $stmt->fetchAll(PDO::FETCH_ASSOC);

    if (empty($trips)) {
        jsonError("No competitor data available for simulation in this country.");
        exit;
    }

    // 2. Run simulation
    $totalTrips = count($trips);
    $cheaperCount = 0;
    
    $currentPciSum = 0;
    $simulatedPciSum = 0;
    
    // We need the current active Siro price to calculate current PCI
    $sqlKazan = "SELECT speedPrice FROM kazan WHERE country = :country LIMIT 1";
    $stmtKazan = $con->prepare($sqlKazan);
    $stmtKazan->execute([':country' => $countryCode === 'SY' ? 'Syria' : ($countryCode === 'JO' ? 'Jordan' : 'Egypt')]);
    $kazanRow = $stmtKazan->fetch(PDO::FETCH_ASSOC);
    $currentSpeedPrice = $kazanRow ? (float)$kazanRow['speedPrice'] : $proposedSpeedPrice;

    foreach ($trips as $trip) {
        $distance = (float)$trip['distance_km'];
        $compPrice = (float)$trip['total_price'];
        
        // Approximate current and simulated Siro prices (ignoring duration/addons for simple simulation)
        $currentSiroPrice = $distance * $currentSpeedPrice;
        $simulatedSiroPrice = $distance * $proposedSpeedPrice;
        
        // Calculate PCIs for this trip (Siro / Competitor)
        $tripCurrentPci = $currentSiroPrice / $compPrice;
        $tripSimulatedPci = $simulatedSiroPrice / $compPrice;
        
        $currentPciSum += $tripCurrentPci;
        $simulatedPciSum += $tripSimulatedPci;
        
        // Check market share (are we cheaper?)
        if ($simulatedSiroPrice < $compPrice) {
            $cheaperCount++;
        }
    }

    $avgCurrentPci = round($currentPciSum / $totalTrips, 2);
    $avgSimulatedPci = round($simulatedPciSum / $totalTrips, 2);
    $simulatedMarketSharePct = round(($cheaperCount / $totalTrips) * 100, 1);
    
    // Suggestion logic
    $recommendation = "neutral";
    $message = "تأثير محايد.";
    
    if ($avgSimulatedPci > 1.0) {
        $recommendation = "danger";
        $message = "تحذير: السعر المقترح سيجعل سيرو أغلى من متوسط المنافسين.";
    } elseif ($avgSimulatedPci < 0.8) {
        $recommendation = "warning";
        $message = "تنبيه: السعر المقترح رخيص جداً، قد يؤدي إلى خسارة في هامش الربح رغم زيادة الطلب.";
    } elseif ($avgSimulatedPci >= 0.9 && $avgSimulatedPci <= 0.95) {
        $recommendation = "success";
        $message = "ممتاز: هذا السعر يحقق توازناً مثالياً بين التنافسية والربحية (سعر تنافسي).";
    }

    jsonSuccess([
        'total_trips_simulated' => $totalTrips,
        'current_speed_price' => $currentSpeedPrice,
        'proposed_speed_price' => $proposedSpeedPrice,
        'current_pci' => $avgCurrentPci,
        'simulated_pci' => $avgSimulatedPci,
        'simulated_market_share_percent' => $simulatedMarketSharePct,
        'recommendation_status' => $recommendation,
        'recommendation_message' => $message
    ]);

} catch (Exception $e) {
    error_log("[what_if_simulator] Error: " . $e->getMessage());
    jsonError("Simulation failed");
}