<?php
header('Content-Type: application/json');
require_once '../db/config.php';

try {
    $pdo = db();
    
    // 1. Fetch data for the alerts table
    $stmt = $pdo->query("
        SELECT 
            a.alert_id,
            a.timestamp,
            w.name as warehouse_name,
            s.name as slot_name,
            n.name as node_name,
            a.metric_name,
            a.actual_value,
            a.threshold_value,
            a.status
        FROM alerts a
        JOIN nodes n ON a.node_id = n.id
        JOIN slots s ON n.slot_id = s.id
        JOIN warehouses w ON s.warehouse_id = w.id
        ORDER BY a.timestamp DESC
    ");
    $alerts = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // 2. Fetch data for overview charts
    // Alerts per warehouse
    $stmt = $pdo->query("
        SELECT w.name, COUNT(a.alert_id) as alert_count
        FROM alerts a
        JOIN nodes n ON a.node_id = n.id
        JOIN slots s ON n.slot_id = s.id
        JOIN warehouses w ON s.warehouse_id = w.id
        GROUP BY w.name
    ");
    $alerts_per_warehouse = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // Alerts over time (last 7 days)
    $stmt = $pdo->query("
        SELECT DATE(timestamp) as alert_date, COUNT(alert_id) as alert_count
        FROM alerts
        WHERE timestamp >= CURDATE() - INTERVAL 7 DAY
        GROUP BY DATE(timestamp)
        ORDER BY alert_date
    ");
    $alerts_over_time = $stmt->fetchAll(PDO::FETCH_ASSOC);

    // Alert status distribution
    $stmt = $pdo->query("
        SELECT status, COUNT(alert_id) as alert_count
        FROM alerts
        GROUP BY status
    ");
    $alert_status_distribution = $stmt->fetchAll(PDO::FETCH_ASSOC);

    echo json_encode([
        'success' => true,
        'alerts' => $alerts,
        'chart_data' => [
            'per_warehouse' => $alerts_per_warehouse,
            'over_time' => $alerts_over_time,
            'status_distribution' => $alert_status_distribution
        ]
    ]);

} catch (Exception $e) {
    http_response_code(500);
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}