<?php

namespace SilverStripe\Forms\GridField;

use SilverStripe\Core\Convert;
use SilverStripe\Forms\HiddenField;
use SilverStripe\ORM\DataList;

/**
 * This class is a snapshot of the current status of a {@link GridField}.
 *
 * It's designed to be inserted into a Form as a HiddenField and passed through
 * to actions such as the {@link GridField_FormAction}.
 *
 * @see GridField
 */
class GridState extends HiddenField
{

    /**
     * @var GridField
     */
    protected $grid;

    /**
     * @var GridState_Data
     */
    protected $data = null;

    /**
     * @param GridField $grid
     * @param string $value JSON encoded string
     */
    public function __construct($grid, $value = null)
    {
        $this->grid = $grid;

        if ($value) {
            $this->setValue($value);
        }

        parent::__construct($grid->getName() . '[GridState]');
    }

    /**
     * @param mixed $d
     * @return object
     */
    public static function array_to_object($d)
    {
        if (is_array($d)) {
            return (object) array_map(function ($item) {
                return GridState::array_to_object($item);
            }, $d ?? []);
        }

        return $d;
    }

    public function setValue($value, $data = null)
    {
        // Apply the value on top of the existing defaults
        $data = json_decode($value ?? '', true);
        if ($data) {
            $this->mergeValues($this->getData(), $data);
        }
        parent::setValue($value);
        return $this;
    }

    private function mergeValues(GridState_Data $data, array $array): void
    {
        foreach ($array as $k => $v) {
            if (is_array($v)) {
                $this->mergeValues($data->$k, $v);
            } else {
                $data->$k = $v;
            }
        }
    }

    /**
     * @return GridState_Data
     */
    public function getData()
    {
        if (!$this->data) {
            $this->data = new GridState_Data();
        }

        return $this->data;
    }

    /**
     * @return DataList
     */
    public function getList()
    {
        return $this->grid->getList();
    }

    /**
     * Returns a json encoded string representation of this state.
     *
     * @return string
     */
    public function Value()
    {
        $data = $this->data ? $this->data->getChangesArray() : [];
        return json_encode($data, JSON_FORCE_OBJECT);
    }

    /**
     * Returns a json encoded string representation of this state.
     *
     * @return string
     */
    public function dataValue()
    {
        return $this->Value();
    }

    /**
     *
     * @return string
     */
    public function attrValue()
    {
        return Convert::raw2att($this->Value());
    }

    /**
     *
     * @return string
     */
    public function __toString()
    {
        return $this->Value();
    }
}