<?php

namespace Ulmus\Query;

use Ulmus\QueryBuilder;

class Values extends Fragment {

    public int $order = 0;
    
    public ? int $fieldCount = null;
    
    public array $rows;
    
    public QueryBuilder $queryBuilder;

    public function __construct(QueryBuilder $queryBuilder)
    {
        $this->queryBuilder = $queryBuilder;
    }
    
    public function add(array $row) : self
    {
        if ($this->fieldCount === null) {        
            $this->fieldCount = count($row);
        }

        # index starts at '1' for Pdo params
        $this->rows[] = array_combine(range(1, count($row)), array_values($row));
        
        return $this;
    }

    public function render() : string
    {
        $this->queryBuilder->addValues($this->flattenRowsArray());
          
        return $this->renderSegments([
            'VALUES', $this->renderParameterPlaceholders(),
        ]);
    }
    
    public function renderParameterPlaceholders() : string 
    {
        $return = [];

        foreach($this->rows as $row) {
            if ($this->fieldCount === null) {
            }
            else {
                if (count($row) !== $this->fieldCount) {
                    throw new \Exception("Insert statement must contains the same number of values for each rows.");
                }
            }
            
            $return[] = implode(',', array_fill(0, $this->fieldCount, '?'));
        }
        
        return "(" . implode('),(', $return) . ")";
    }
    
    public function flattenRowsArray() : array
    {
        return \iterator_to_array(new \RecursiveIteratorIterator(new \RecursiveArrayIterator($this->rows)));
    }
}