<?php

namespace PhpOffice\PhpSpreadsheet\Calculation\Token;

use PhpOffice\PhpSpreadsheet\Calculation\Calculation;

> use PhpOffice\PhpSpreadsheet\Calculation\Engine\BranchPruner;



class Stack
{
    /**

>      * @var BranchPruner
     * The parser stack for formulae.
>      */
     *
>     private $branchPruner;
     * @var mixed[]
> 
     */
>     /**


    private $stack = [];

    /**
     * Count of entries in the parser stack.
     *
     * @var int
     */
    private $count = 0;


>     public function __construct(BranchPruner $branchPruner)
    /**
>     {
     * Return the number of entries on the stack.
>         $this->branchPruner = $branchPruner;
     *
>     }
     * @return int
> 



<      *
<      * @return int



<     public function count()



>     public function count(): int


        return $this->count;
    }

    /**
     * Push a new entry onto the stack.
     *

<      * @param mixed $type


     * @param mixed $value

<      * @param mixed $reference
<      * @param null|string $storeKey will store the result under this alias
<      * @param null|string $onlyIf will only run computation if the matching
<      *      store key is true
<      * @param null|string $onlyIfNot will only run computation if the matching
<      *      store key is false
<      */
<     public function push(
<         $type,
<         $value,
<         $reference = null,
<         $storeKey = null,
<         $onlyIf = null,
<         $onlyIfNot = null
<     ): void {
<         $stackItem = $this->getStackItem($type, $value, $reference, $storeKey, $onlyIf, $onlyIfNot);
< 



>      */
>     public function push(string $type, $value, ?string $reference = null): void
>     {
>         $stackItem = $this->getStackItem($type, $value, $reference);


        $this->stack[$this->count++] = $stackItem;


<         if ($type == 'Function') {



>         if ($type === 'Function') {


            $localeFunction = Calculation::localeFunc($value);
            if ($localeFunction != $value) {
                $this->stack[($this->count - 1)]['localeValue'] = $localeFunction;
            }
        }
    }


<     public function getStackItem(
<         $type,
<         $value,
<         $reference = null,
<         $storeKey = null,
<         $onlyIf = null,
<         $onlyIfNot = null
<     ) {



>     public function pushStackItem(array $stackItem): void
>     {
>         $this->stack[$this->count++] = $stackItem;
>     }
> 
>     /**
>      * @param mixed $value
>      */
>     public function getStackItem(string $type, $value, ?string $reference = null): array
>     {


        $stackItem = [
            'type' => $type,
            'value' => $value,
            'reference' => $reference,
        ];


<         if (isset($storeKey)) {



>         // will store the result under this alias
>         $storeKey = $this->branchPruner->currentCondition();
>         if (isset($storeKey) || $reference === 'NULL') {


            $stackItem['storeKey'] = $storeKey;
        }


<         if (isset($onlyIf)) {



>         // will only run computation if the matching store key is true
>         $onlyIf = $this->branchPruner->currentOnlyIf();
>         if (isset($onlyIf) || $reference === 'NULL') {


            $stackItem['onlyIf'] = $onlyIf;
        }


<         if (isset($onlyIfNot)) {



>         // will only run computation if the matching store key is false
>         $onlyIfNot = $this->branchPruner->currentOnlyIfNot();
>         if (isset($onlyIfNot) || $reference === 'NULL') {


            $stackItem['onlyIfNot'] = $onlyIfNot;
        }

        return $stackItem;
    }

    /**
     * Pop the last entry from the stack.

<      *
<      * @return mixed


     */

<     public function pop()



>     public function pop(): ?array


    {
        if ($this->count > 0) {
            return $this->stack[--$this->count];
        }

        return null;
    }

    /**
     * Return an entry from the stack without removing it.

<      *
<      * @param int $n number indicating how far back in the stack we want to look
<      *
<      * @return mixed


     */

<     public function last($n = 1)



>     public function last(int $n = 1): ?array


    {
        if ($this->count - $n < 0) {
            return null;
        }

        return $this->stack[$this->count - $n];
    }

    /**
     * Clear the stack.
     */
    public function clear(): void
    {
        $this->stack = [];
        $this->count = 0;

<     }
< 
<     public function __toString()
<     {
<         $str = 'Stack: ';
<         foreach ($this->stack as $index => $item) {
<             if ($index > $this->count - 1) {
<                 break;
<             }
<             $value = $item['value'] ?? 'no value';
<             while (is_array($value)) {
<                 $value = array_pop($value);
<             }
<             $str .= $value . ' |> ';
<         }
< 
<         return $str;


    }
}