<?php
declare(strict_types=1);


namespace Database\Traits;


use Database\ActiveQuery;
use Database\ISqlBuilder;
use Exception;
use JetBrains\PhpStorm\Pure;


/**
 * Class CaseWhen
 * @package Database\Traits
 */
class When
{

    public ActiveQuery|ISqlBuilder $query;


    private array $_condition = [];

    private string $else = '';


    /**
     * CaseWhen constructor.
     * @param string $column
     * @param ActiveQuery|ISqlBuilder $activeQuery
     */
    public function __construct(public string $column, public ActiveQuery|ISqlBuilder $activeQuery)
    {
        $this->_condition[] = 'CASE ' . $column;
    }


    /**
     * @param string|int $condition
     * @param string $then
     * @return $this
     * @throws
     */
    public function when(string|int $condition, string $then): static
    {
        $this->_condition[] = sprintf('WHEN %s THEN %s', $condition, $then);

        return $this;
    }


    /**
     * @param string $alias
     */
    public function else(string $alias): void
    {
        $this->else = $alias;
    }


    /**
     * @return string
     */
    #[Pure] public function end(): string
    {
        if (empty($this->_condition)) {
            return '';
        }
        $prefix = implode(' ', $this->_condition);
        if (!empty($this->else)) {
            $prefix .= ' ELSE ' . $this->else;
        }
        return '(' . $prefix . ' END)';
    }

}