<?php namespace klmn;

class ArrayTransform
{
    private $rows;

    public function __construct($rows = array())
    {
        $this->rows = $rows;
    }

    public function _rows_by($index_field_name)
    {
        $output = array();
        foreach ( $this->rows as $row )
            $output[$row[$index_field_name]] = $row;

        return $output;
    }

    public function _rows_by_id()
    {
        return $this->_rows_by('id');
    }

    public function _column($field_name)
    {
        $output = array();
        foreach ( $this->rows as $n => $row )
            $output[$n] = $row[$field_name];

        return $output;
    }

    public function _columns($list = array())
    {
        $output = array();
        foreach ( $this->rows as $n => $row )
        {
            foreach ( $row as $field_name => $value )
            {
                if ( !$list || in_array($field_name, $list) )
                    $output[$field_name][$n] = $value;
            }
        }

        return $output;
    }

    public function _cell($field_name)
    {
        if ( $this->rows )
            return $this->rows[0][$field_name];
    }

    public function _cells_by($index_field_name, $value_field_name)
    {
        $output = array();
        foreach ( $this->rows as $row )
            $output[$row[$index_field_name]] = $row[$value_field_name];

        return $output;
    }

    public function _cells_by_id($value_field_name)
    {
        $output = array();
        foreach ( $this->rows as $row )
            $output[$row['id']] = $row[$value_field_name];

        return $output;
    }
}