<?php


namespace PhpMyAdmin\SqlParser\Components;

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

/**
 * `JOIN` keyword parser.
 *
 * @category   Keywords
 *
 * @license    https://www.gnu.org/licenses/gpl-2.0.txt GPL-2.0+
 */
class JoinKeyword extends Component
{
    public static $JOINS = array(
        'CROSS JOIN' => 'CROSS',
        'FULL JOIN' => 'FULL',
        'FULL OUTER JOIN' => 'FULL',
        'INNER JOIN' => 'INNER',
        'JOIN' => 'JOIN',
        'LEFT JOIN' => 'LEFT',
        'LEFT OUTER JOIN' => 'LEFT',
        'RIGHT JOIN' => 'RIGHT',
        'RIGHT OUTER JOIN' => 'RIGHT',
        'NATURAL JOIN' => 'NATURAL',
        'NATURAL LEFT JOIN' => 'NATURAL LEFT',
        'NATURAL RIGHT JOIN' => 'NATURAL RIGHT',
        'NATURAL LEFT OUTER JOIN' => 'NATURAL LEFT OUTER',
        'NATURAL RIGHT OUTER JOIN' => 'NATURAL RIGHT OUTER',
        'STRAIGHT_JOIN' => 'STRAIGHT'
    );

    public $type;

    public $expr;

    public $on;

    public $using;

    public function __construct($type = null, $expr = null, $on = null, $using = null)
    {
        $this->type = $type;
        $this->expr = $expr;
        $this->on = $on;
        $this->using = $using;
    }

    public static function parse(Parser $parser, TokensList $list, array $options = array())
    {
        $ret = array();

        $expr = new self();

        $state = 0;

        if ($list->idx > 0) {
            --$list->idx;
        }

        for (; $list->idx < $list->count; ++$list->idx) {
            $token = $list->tokens[$list->idx];

            if ($token->type === Token::TYPE_DELIMITER) {
                break;
            }

            if (($token->type === Token::TYPE_WHITESPACE) || ($token->type === Token::TYPE_COMMENT)) {
                continue;
            }

            if ($state === 0) {
                if (($token->type === Token::TYPE_KEYWORD)
                    && ! empty(static::$JOINS[$token->keyword])
                ) {
                    $expr->type = static::$JOINS[$token->keyword];
                    $state = 1;
                } else {
                    break;
                }
            } elseif ($state === 1) {
                $expr->expr = Expression::parse($parser, $list, array('field' => 'table'));
                $state = 2;
            } elseif ($state === 2) {
                if ($token->type === Token::TYPE_KEYWORD) {
                    switch ($token->keyword) {
                        case 'ON':
                            $state = 3;
                            break;
                        case 'USING':
                            $state = 4;
                            break;
                        default:
                            if (! empty(static::$JOINS[$token->keyword])
                            ) {
                                $ret[] = $expr;
                                $expr = new self();
                                $expr->type = static::$JOINS[$token->keyword];
                                $state = 1;
                            } else {
                                break 2;
                            }
                            break;
                    }
                }
            } elseif ($state === 3) {
                $expr->on = Condition::parse($parser, $list);
                $ret[] = $expr;
                $expr = new self();
                $state = 0;
            } elseif ($state === 4) {
                $expr->using = ArrayObj::parse($parser, $list);
                $ret[] = $expr;
                $expr = new self();
                $state = 0;
            }
        }

        if (! empty($expr->type)) {
            $ret[] = $expr;
        }

        --$list->idx;

        return $ret;
    }

    public static function build($component, array $options = array())
    {
        $ret = array();
        foreach ($component as $c) {
            $ret[] = array_search($c->type, static::$JOINS) . ' ' . $c->expr
                . (! empty($c->on)
                    ? ' ON ' . Condition::build($c->on) : '')
                . (! empty($c->using)
                    ? ' USING ' . ArrayObj::build($c->using) : '');
        }

        return implode(' ', $ret);
    }
}
