<?php

session_start();

if (empty($_SESSION['access_granted_kampfrichter']) || $_SESSION['access_granted_kampfrichter'] !== true || empty($_SESSION['passcodekampfrichter_id']) || $_SESSION['passcodekampfrichter_id'] < 1) {
	http_response_code(403);
	exit;
}

//ini_set('display_errors', 1);
//ini_set('display_startup_errors', 1);

header('Content-Type: application/json');

if (!isset($baseDir)) {
    $baseDir = $_SERVER['DOCUMENT_ROOT'];
}

$type = 'kr';

$data = require $baseDir . '/../scripts/db/db-verbindung-script.php';

if ($data['success'] === false){
	echo json_encode(['success' => false, 'message' => $data['message']]);
    exit; 
}

require $baseDir . '/../scripts/db/db-functions.php';
require $baseDir . '/../scripts/db/db-tables.php';

$noten = db_select($mysqli, $tableNotenBezeichnungen, "id, berechnung, type");

// 1. Re-index the array so the keys match the database IDs
$notenById = array_column($noten, null, 'id');

$berechnungen = [];
foreach ($notenById as $id => $sn) {
    if ($sn['type'] === 'berechnung') {
        $berechnungen[] = $sn;
    }
}

if (empty($berechnungen)) {
    echo json_encode(['success' => true, 'message' => "Keine Berechnungen ausgewählt"]);
    exit;
}

require $baseDir . "/../scripts/string-calculator/string-calculator-functions.php";
$notenRechner = new NotenRechner();

// 1. Build the direct map
// Format: [ Changed_Note_ID => [ "CalcId|GeraetId" => [CalcId, GeraetId] ] ]
$dependencyMap = [];

foreach ($berechnungen as $calc) {
    $neededIdsArray = $notenRechner->getBenoetigteIdsComplex($calc['berechnung']);
    
    if (empty($neededIdsArray)) { 
        continue; 
    }

    $calcId = (int)$calc['id'];

    foreach ($neededIdsArray as $needed) {
        $nId = (int)$needed['noteId'];
        
        // Keep geraetId as integer if it's a number (e.g., 3), otherwise string ('S')
        $gId = is_numeric($needed['geraetId']) ? (int)$needed['geraetId'] : $needed['geraetId'];
        
        // Create a unique string key so we don't store exact duplicates
        $nodeKey = $calcId . '|' . $gId;
        
        if (!isset($dependencyMap[$nId])) {
            $dependencyMap[$nId] = [];
        }
        
        // Store it as the "little array" you requested: [DependentCalcId, GeraetId]
        $dependencyMap[$nId][$nodeKey] = [$calcId, $gId];
    }
}


// 2. Our recursive helper function (Updated for complex nodes)
function getCompleteDependencyChain($id, $directMap, $visited = []) 
{
    // If this ID doesn't have anything depending on it, return empty
    if (!isset($directMap[$id])) {
        return [];
    }

    $allDependencies = [];

    foreach ($directMap[$id] as $nodeKey => $complexNode) {
        // CIRCULAR DEPENDENCY CHECK:
        // We check against the string key (e.g., "10|S") to prevent infinite loops
        if (isset($visited[$nodeKey])) {
            continue;
        }

        // 1. Mark this specific node as visited
        $visited[$nodeKey] = true;

        // 2. Add the little array [CalcId, GeraetId] to our master list
        $allDependencies[$nodeKey] = $complexNode;

        // 3. Recursively find everything that depends on THIS calculation ID
        // $complexNode[0] is the dependent Calc ID
        $childDependencies = getCompleteDependencyChain($complexNode[0], $directMap, $visited);
        
        // 4. Merge the child results into our master list safely
        foreach ($childDependencies as $childKey => $childNode) {
            $allDependencies[$childKey] = $childNode;
            $visited[$childKey] = true; // Ensure the parent loop knows this was visited
        }
    }

    return $allDependencies;
}


// 3. Create the final flattened map for ALL IDs
$flatDependencyMap = [];

foreach (array_keys($notenById) as $id) {
    $chain = getCompleteDependencyChain($id, $dependencyMap);
    
    // Only add it if dependencies exist
    if (!empty($chain)) {
        // array_values() removes the "10|S" string keys, turning it into a perfect 
        // 0-indexed array for clean JSON encoding: [[10, "S"], [12, 3]]
        $flatDependencyMap[$id] = array_values($chain);
    }
}


// 4. Database Updates
// Step 1: Reset all rows to NULL in a single query
$resetSql = "UPDATE $tableNotenBezeichnungen SET `berechnung_json` = NULL";
$mysqli->query($resetSql);

// Step 2: Prepare the statement
$updateSql = "UPDATE $tableNotenBezeichnungen SET `berechnung_json` = ? WHERE id = ?";
$stmt = $mysqli->prepare($updateSql);

foreach ($flatDependencyMap as $id => $completeDependencyArray) {
    if (empty($completeDependencyArray)) {
        continue;
    }

    $jsonString = json_encode($completeDependencyArray);
    
    // Bind parameters: 's' for string (JSON), 'i' for integer (ID)
    $stmt->bind_param("si", $jsonString, $id);
    $stmt->execute();
}

$stmt->close();

echo json_encode(['success' => true, 'message' => "Abhaengigkeiten berechnet"]);
exit;