gistfile1.txt

$a = [
    2023 => [
        'maj' => [
            12 => 13,
            23 => 20
        ],
        'lipiec' => [
            5 => 14
        ]
    ],
    2024 => [
        'luty' => [
            23 => 66
        ],
        'grudzień' => [
            18 => 100,
            26 => 5
        ]
    ]
];

$b = ['year', 'month', 'day'];

$c = [
    ['year' => '2023', 'month' => 'maj', 'day' => 12, 'data' => 13],
    ['year' => '2023', 'month' => 'maj', 'day' => 23, 'data' => 20],
    ['year' => '2023', 'month' => 'lipiec', 'day' => 5, 'data' => 14],
    ['year' => '2024', 'month' => 'luty', 'day' => 23, 'data' => 66],
    ['year' => '2024', 'month' => 'grudzień', 'day' => 18, 'data' => 100],
    ['year' => '2024', 'month' => 'grudzień', 'day' => 26, 'data' => 5],
];


function processNode($a, $b, &$row, &$rows, int $level = 1)
{
    if ((count($b) + 1) === $level) {
        $row['data'] = $a;
        $rows[] = $row;

        return;
    }

    if (! is_array($a)) {
        echo "Data size mismatch\n";

        return;
    }

    foreach ($a as $k => $v) {
        $row[$b[$level - 1]] = $k;

        processNode($v, $b, $row, $rows, $level + 1);
    }
}


$row = [];
$rows = [];
processNode($a, $b, $row, $rows);
var_dump($rows);


$b = ['year', 'month',];

$row = [];
$rows = [];
processNode($a, $b, $row, $rows);
var_dump($rows);


$b = ['year', 'month', 'sss', 'ddd'];

$row = [];
$rows = [];
processNode($a, $b, $row, $rows);
var_dump($rows);


Results:

/bin/php /home/ot/.config/JetBrains/PhpStorm2024.3/scratches/scratch_6.php
array(6) {
  [0]=>
  array(4) {
    ["year"]=>
    int(2023)
    ["month"]=>
    string(3) "maj"
    ["day"]=>
    int(12)
    ["data"]=>
    int(13)
  }
  [1]=>
  array(4) {
    ["year"]=>
    int(2023)
    ["month"]=>
    string(3) "maj"
    ["day"]=>
    int(23)
    ["data"]=>
    int(20)
  }
  [2]=>
  array(4) {
    ["year"]=>
    int(2023)
    ["month"]=>
    string(6) "lipiec"
    ["day"]=>
    int(5)
    ["data"]=>
    int(14)
  }
  [3]=>
  array(4) {
    ["year"]=>
    int(2024)
    ["month"]=>
    string(4) "luty"
    ["day"]=>
    int(23)
    ["data"]=>
    int(66)
  }
  [4]=>
  array(4) {
    ["year"]=>
    int(2024)
    ["month"]=>
    string(9) "grudzień"
    ["day"]=>
    int(18)
    ["data"]=>
    int(100)
  }
  [5]=>
  array(4) {
    ["year"]=>
    int(2024)
    ["month"]=>
    string(9) "grudzień"
    ["day"]=>
    int(26)
    ["data"]=>
    int(5)
  }
}

======================

array(4) {
  [0]=>
  array(3) {
    ["year"]=>
    int(2023)
    ["month"]=>
    string(3) "maj"
    ["data"]=>
    array(2) {
      [12]=>
      int(13)
      [23]=>
      int(20)
    }
  }
  [1]=>
  array(3) {
    ["year"]=>
    int(2023)
    ["month"]=>
    string(6) "lipiec"
    ["data"]=>
    array(1) {
      [5]=>
      int(14)
    }
  }
  [2]=>
  array(3) {
    ["year"]=>
    int(2024)
    ["month"]=>
    string(4) "luty"
    ["data"]=>
    array(1) {
      [23]=>
      int(66)
    }
  }
  [3]=>
  array(3) {
    ["year"]=>
    int(2024)
    ["month"]=>
    string(9) "grudzień"
    ["data"]=>
    array(2) {
      [18]=>
      int(100)
      [26]=>
      int(5)
    }
  }
}

====================

Data size mismatch
Data size mismatch
Data size mismatch
Data size mismatch
Data size mismatch
Data size mismatch
array(0) {
}

Process finished with exit code 0