CountStatement.php

<?php

namespace Tempest\Database\QueryStatements;

use Tempest\Database\Builder\TableDefinition;
use Tempest\Database\Config\DatabaseDialect;
use Tempest\Database\QueryStatement;
use Tempest\Support\Arr\ImmutableArray;

use function Tempest\Support\arr;

final class CountStatement implements QueryStatement, HasWhereStatements
{
    /**
     * @param ImmutableArray<WhereStatement> $where
     * @param ImmutableArray<JoinStatement> $joins
     */
    public function __construct(
        public readonly TableDefinition $table,
        public ?string $column = null,
        public ImmutableArray $where = new ImmutableArray(),
        public bool $distinct = false,
        public ImmutableArray $joins = new ImmutableArray(),
    ) {}

    public function compile(DatabaseDialect $dialect): string
    {
        $countField = new FieldStatement(sprintf(
            'COUNT(%s) AS %s',
            $this->getCountArgument(),
            $this->getKey(),
        ));

        $query = arr([
            sprintf('SELECT %s', $countField->compile($dialect)),
            sprintf('FROM %s', $dialect->quoteIdentifier($this->table->name)),
        ]);

        if ($this->joins->isNotEmpty()) {
            foreach ($this->joins as $join) {
                $query[] = $join->compile($dialect);
            }
        }

        if ($this->where->isNotEmpty()) {
            $query[] = 'WHERE ' . $this->where
                ->map(fn (QueryStatement $where) => $where->compile($dialect))
                ->filter(fn (string $compiled) => $compiled !== '')
                ->implode(' ');
        }

        return $query->implode(' ');
    }

    public function getCountArgument(): string
    {
        return $this->column === null || $this->column === '*'
            ? '*'
            : sprintf(
                '%s`%s`',
                $this->distinct ? 'DISTINCT ' : '',
                $this->column,
            );
    }

    public function getKey(): string
    {
        return 'count';
    }
}