<?php
/**
 * getTreeData.php - Liefert Klassifikationsdaten im jsTree-Format
 * 
 * Nutzt die bestehende Treeview-Tabelle
 * 
 * Parameter:
 * - id: Parent-ID (# oder 0 für Root-Ebene)
 * 
 * Rückgabe: JSON-Array im jsTree-Format
 */

header('Content-Type: application/json; charset=utf-8');

// Datenbankverbindung
include "db_connection.php";

$conn = mysqli_connect(HOST, USER, PASSWORD, DATABASE);
if (mysqli_connect_errno()) {
    echo json_encode([]);
    exit();
}

mysqli_set_charset($conn, "utf8");

// Parameter auslesen
$parentId = isset($_GET['id']) ? $_GET['id'] : '#';

// Root-Ebene: parent_id ist NULL oder 0
if ($parentId === '#' || $parentId === '0' || $parentId === 0) {
    $sql = "SELECT id, name, text, link as href, parent_id 
            FROM Treeview 
            WHERE parent_id IS NULL OR parent_id = 0 OR parent_id = ''
            ORDER BY text";
} else {
    // Unterebene: Kinder des angegebenen Parents
    $parentId = intval($parentId);
    $sql = "SELECT id, name, text, link as href, parent_id 
            FROM Treeview 
            WHERE parent_id = $parentId
            ORDER BY text";
}

$res = mysqli_query($conn, $sql);

if (!$res) {
    echo json_encode([]);
    exit();
}

$result = [];

while ($row = mysqli_fetch_assoc($res)) {
    // Prüfen ob dieser Knoten Kinder hat
    $childCheckSql = "SELECT COUNT(*) as cnt FROM Treeview WHERE parent_id = " . intval($row['id']);
    $childRes = mysqli_query($conn, $childCheckSql);
    $childRow = mysqli_fetch_assoc($childRes);
    $hasChildren = ($childRow['cnt'] > 0);
    
    $result[] = [
        'id' => strval($row['id']),
        'text' => $row['text'] ? $row['text'] : $row['name'],
        'children' => $hasChildren,
        'data' => [
            'name' => $row['name'],
            'href' => $row['href']
        ],
        'icon' => $hasChildren ? 'fas fa-folder text-warning' : 'fas fa-file text-secondary'
    ];
}

mysqli_close($conn);

echo json_encode($result, JSON_UNESCAPED_UNICODE);
?>