<?php

namespace App\Models;

/**
 * Row in a data table
 *
 * @property int $id
 * @property string $data - JSONB, always containing _grid
 */
class Row extends BaseModel
{
    protected $casts = [
        'data' => 'object',
    ];

    protected $guarded = [];
    public $timestamps = false;

    public function getGridAttribute() {
        return $this->data->_grid;
    }

    public function setGridAttribute($value) {
        $this->data->_grid = $value;
    }

    /**
     * Allocate a single Global Row ID, application-unique.
     *
     * GRIDs are used to uniquely identify existing or proposed new rows,
     * and are preserved after row modifications, to ensure change proposals have
     * a clear target.
     *
     * @return int
     */
    public static function allocateGRID()
    {
        return \DB::selectOne("SELECT nextval('global_row_id_seq') AS grid;")->grid;
    }

    /**
     * Allocate a block of Global Row IDs, application-unique.
     *
     * @see Row::allocateGRID()
     *
     * @return int[] first and last
     */
    public static function allocateGRIDs($count)
    {
        $last = \DB::selectOne("SELECT multi_nextval('global_row_id_seq', ?) AS last_grid;", [$count])->last_grid;
        return [$last - $count + 1, $last];
    }
}