<?php


namespace App\Tables;

use App\Models\Revision;
use App\Models\Table;
use Illuminate\Queue\SerializesModels;
use ReflectionClass;

/**
 * Object representing a set of table modifications
 */
class Changeset
{
    use SerializesModels;

    const object_excluded_properties = [
        'revision',
        'table',
        'note',
    ];

    /**
     * @var Revision - base revision this changeset belongs to
     */
    public $revision;

    /**
     * @var Table - table this changeset belongs to
     */
    public $table;

    /**
     * @var string - user's note attached to this changeset (future proposal)
     */
    public $note;

    /**
     * Rows whose content changed, identified by _id.
     * Only changed values are to be filled. Columns are identified by GCIDs
     *
     * @var array|null - [[_id:…, …], …]
     */
    public $rowUpdates;

    /**
     * New rows in the full Row::data format, including GRIDs.
     * Values are identified by GCIDs from previously defined, or new columns.
     *
     * @var array|null - [[_id:…, …], …]
     */
    public $newRows;

    /**
     * Rows to be removed
     *
     * @var int[]|null - GRIDs
     */
    public $removedRows;

    /**
     * Values changed in column specifications, such as name, title, etc.
     * This does not affect the table rows in any way.
     *
     * @var array[] - column specification objects, with GCIDs
     */
    public $columnUpdates;

    /**
     * New columns in the full format, including GCIDs
     *
     * @var array|null - [[id:…, …], …]
     */
    public $newColumns;

    /**
     * When reordering columns, here is the column IDs array
     * in the new order. Columns meanwhile removed from the table
     * or added to it are to be ignored or appended at the end.
     *
     * This shall not be filled if merely editing or adding columns,
     * unless the order is explicitly adjusted by the user.
     *
     * @var string[]|null - GCIDs
     */
    public $columnOrder;

    /**
     * Columns to be removed
     *
     * The data associated to those columns may or may not be removed from the Rows.
     * It does not matter, other than in regard to the table size.
     *
     * @var int[]|null - GCIDs
     */
    public $removedColumns;

    private function walkProps()
    {
        $properties = (new ReflectionClass($this))->getProperties();

        foreach ($properties as $property) {
            if (in_array($property->name, self::object_excluded_properties)) {
                continue;
            }

            yield $property->name;
        }
    }

    /**
     * Reconstruct from a object, such as one found in Proposal.
     * Note that the fromProposal() method should be used when the
     * proposal is available, as it populates additional fields.
     *
     * @param \stdClass $changes
     * @return Changeset
     */
    public static function fromObject($changes)
    {
        $changeset = new Changeset();

        foreach ($changeset->walkProps() as $prop) {
            if (isset($changes->$prop)) {
                $changeset->$prop = $changes->$prop;
            }
        }

        return $changeset;
    }

    /**
     * Serialize to an object format that may be stored in a Proposal.
     *
     * @return \stdClass
     */
    public function toObject()
    {
        $object = new \stdClass();

        foreach ($this->walkProps() as $prop) {
            $object->$prop = array_values($this->$prop);
        }

        return $object;
    }

    public function hasAnyChanges()
    {
        foreach ($this->walkProps() as $prop) {
            if (!empty($this->$prop)) {
                return true;
            }
        }

        return false;
    }
}