<?php
/**
 * surge_opportunity_index.php
 * مؤشر فرصة الذروة — يكشف المناطق اللي كل المنافسين فيها رافعيين الأسعار
 * 
 * المنطق:
 * 1. لكل منطقة grid (~1.5km)، لكل منافس
 * 2. baseline = متوسط price_per_km آخر 7 أيام (بدون آخر 6 ساعات)
 * 3. current = متوسط price_per_km آخر ساعتين
 * 4. إذا current > baseline × 1.2 → المنافس في surge
 * 5. إذا كل المنافسين النشطين في zone في surge → فرصة ذروة ✅
 */

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 = filterRequest('country_code');

    $where = '';
    $params = [];
    if ($countryCode) {
        $where = 'AND cp.country_code = :country';
        $params[':country'] = strtoupper($countryCode);
    }

    // 1. حساب الـ baseline (آخر 7 أيام، بدون آخر 6 ساعات)
    //    و current (آخر ساعتين) لكل منافس في كل خلية grid
    $sql = "SELECT 
                ROUND(cp.from_latitude * 74, 0) / 74 AS lat_group,
                ROUND(cp.from_longitude * 74, 0) / 74 AS lng_group,
                cp.competitor_name,
                cp.country_code,
                AVG(CASE WHEN cp.created_at < DATE_SUB(NOW(), INTERVAL 6 HOUR)
                         THEN cp.price_per_km END) AS baseline_avg,
                AVG(CASE WHEN cp.created_at >= DATE_SUB(NOW(), INTERVAL 2 HOUR)
                         THEN cp.price_per_km END) AS current_avg,
                COUNT(*) AS total_samples,
                SUM(CASE WHEN cp.created_at >= DATE_SUB(NOW(), INTERVAL 2 HOUR) THEN 1 ELSE 0 END) AS recent_samples
            FROM competitor_prices cp
            WHERE cp.created_at >= DATE_SUB(NOW(), INTERVAL 7 DAY)
              AND cp.price_per_km > 0
              $where
            GROUP BY lat_group, lng_group, cp.competitor_name, cp.country_code
            HAVING recent_samples >= 2
            ORDER BY lat_group, lng_group, cp.competitor_name";

    $stmt = $con->prepare($sql);
    if ($countryCode) {
        foreach ($params as $k => $v) {
            $stmt->bindValue($k, $v);
        }
    }
    $stmt->execute();
    $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // 2. تجميع البيانات لكل zone
    $zones = [];
    foreach ($rows as $row) {
        $zoneKey = $row['lat_group'] . '_' . $row['lng_group'];
        
        $baseline = (float)$row['baseline_avg'];
        $current  = (float)$row['current_avg'];
        
        $surgeRatio = ($baseline > 0) ? round($current / $baseline, 2) : 1.0;
        $isSurging = $baseline > 0 && $surgeRatio >= 1.2;

        if (!isset($zones[$zoneKey])) {
            $zones[$zoneKey] = [
                'lat'            => (float)$row['lat_group'],
                'lng'            => (float)$row['lng_group'],
                'country_code'   => $row['country_code'],
                'competitors'    => [],
                'total_active'   => 0,
                'total_surging'  => 0,
            ];
        }

        $zones[$zoneKey]['competitors'][] = [
            'name'        => $row['competitor_name'],
            'baseline'    => round($baseline, 2),
            'current'     => round($current, 2),
            'surge_ratio' => $surgeRatio,
            'is_surging'  => $isSurging,
        ];
        $zones[$zoneKey]['total_active']++;
        if ($isSurging) {
            $zones[$zoneKey]['total_surging']++;
        }
    }

    // 3. تحديد فرص الذروة
    $opportunities = [];
    $gridSurgeZones = [];

    foreach ($zones as $key => &$zone) {
        $zone['opportunity'] = (
            $zone['total_active'] >= 1 &&
            $zone['total_surging'] === $zone['total_active']
        );

        if ($zone['opportunity']) {
            // حساب متوسط نسبة surge للمنافسين
            $avgRatio = 0;
            foreach ($zone['competitors'] as $c) {
                $avgRatio += $c['surge_ratio'];
            }
            $avgRatio /= count($zone['competitors']);

            // اقتراح multiplier لـ Siro (أقل من المنافسين بفارق بسيط)
            $suggestedMultiplier = round(1.0 + ($avgRatio - 1.0) * 0.6, 2);
            if ($suggestedMultiplier < 1.0) $suggestedMultiplier = 1.0;

            $zone['suggested_multiplier'] = $suggestedMultiplier;

            $opportunities[] = [
                'lat'                 => $zone['lat'],
                'lng'                 => $zone['lng'],
                'country_code'        => $zone['country_code'],
                'surging_competitors' => array_column(
                    array_filter($zone['competitors'], fn($c) => $c['is_surging']),
                    'name'
                ),
                'avg_competitor_surge_ratio' => round($avgRatio, 2),
                'suggested_siro_multiplier'  => $suggestedMultiplier,
            ];

            // حفظ المنطقة في Redis (للقراءة من get.php بعدين)
            $gridSurgeZones[$key] = $suggestedMultiplier;
        }
    }
    unset($zone);

    // 4. تخزين فرص الذروة في Redis بصلاحية 10 دقائق
    if (!empty($gridSurgeZones) && isset($redis) && $redis !== null) {
        $redisKey = 'surge:opportunities';
        $redis->setex($redisKey, 600, json_encode($gridSurgeZones));
    }

    jsonSuccess([
        'total_zones'          => count($zones),
        'opportunities_count'  => count($opportunities),
        'opportunities'        => $opportunities,
        'zone_details'         => array_values($zones),
    ]);

} catch (Exception $e) {
    error_log("[surge_opportunity_index] Error: " . $e->getMessage());
    jsonError("Failed to calculate surge opportunity index");
}