<?php

/**
 * `INTO` keyword parser.
 *
 * @package    SqlParser
 * @subpackage Components
 */
namespace SqlParser\Components;

use SqlParser\Component;
use SqlParser\Parser;
use SqlParser\Token;
use SqlParser\TokensList;

/**
 * `INTO` keyword parser.
 *
 * @category   Keywords
 * @package    SqlParser
 * @subpackage Components
 * @author     Dan Ungureanu <udan1107@gmail.com>
 * @license    http://opensource.org/licenses/GPL-2.0 GNU Public License
 */
class IntoKeyword extends Component
{

    /**
     * Type of target (OUTFILE or SYMBOL).
     *
     * @var string
     */
    public $type;

    /**
     * The destination, which can be a table or a file.
     *
     * @var string|Expression
     */
    public $dest;

    /**
     * The name of the columns.
     *
     * @var array
     */
    public $columns;

    /**
     * @param Parser     $parser  The parser that serves as context.
     * @param TokensList $list    The list of tokens that are being parsed.
     * @param array      $options Parameters for parsing.
     *
     * @return IntoKeyword
     */
    public static function parse(Parser $parser, TokensList $list, array $options = array())
    {
        $ret = new IntoKeyword();

        /**
         * The state of the parser.
         *
         * Below are the states of the parser.
         *
         *      0 -----------------------[ name ]----------------------> 1
         *      0 ---------------------[ OUTFILE ]---------------------> 2
         *
         *      1 ------------------------[ ( ]------------------------> (END)
         *
         *      2 ---------------------[ filename ]--------------------> 1
         *
         * @var int $state
         */
        $state = 0;

        for (; $list->idx < $list->count; ++$list->idx) {
            /**
             * Token parsed at this moment.
             *
             * @var Token $token
             */
            $token = $list->tokens[$list->idx];

            // End of statement.
            if ($token->type === Token::TYPE_DELIMITER) {
                break;
            }

            // Skipping whitespaces and comments.
            if (($token->type === Token::TYPE_WHITESPACE) || ($token->type === Token::TYPE_COMMENT)) {
                continue;
            }

            if (($token->type === Token::TYPE_KEYWORD) && ($token->flags & Token::FLAG_KEYWORD_RESERVED)) {
                if (($state === 0) && ($token->value === 'OUTFILE')) {
                    $ret->type = 'OUTFILE';
                    $state = 2;
                    continue;
                }

                // No other keyword is expected.
                break;
            }

            if ($state === 0) {
                $ret->dest = Expression::parse(
                    $parser,
                    $list,
                    array(
                        'parseField' => 'table',
                        'breakOnAlias' => true,
                    )
                );
                $state = 1;
            } elseif ($state === 1) {
                if (($token->type === Token::TYPE_OPERATOR) && ($token->value === '(')) {
                    $ret->columns = ArrayObj::parse($parser, $list)->values;
                    ++$list->idx;
                }
                break;
            } elseif ($state === 2) {
                $ret->dest = $token->value;
                ++$list->idx;
                break;
            }
        }

        --$list->idx;
        return $ret;
    }

    /**
     * @param IntoKeyword $component The component to be built.
     * @param array       $options   Parameters for building.
     *
     * @return string
     */
    public static function build($component, array $options = array())
    {
        if ($component->dest instanceof Expression) {
            $columns = !empty($component->columns) ?
                '(' . implode(', ', $component->columns) . ')' : '';
            return $component->dest . $columns;
        } else {
            return 'OUTFILE "' . $component->dest . '"';
        }
    }
}
