PhpMyAdmin\SqlParser\Parsers\Keys::parse()

Complexity

Conditions	31
Paths	3

Size

Total Lines	131
Code Lines	65

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	60
CRAP Score	31

Importance

Changes	1
Bugs	0	Features	0

<?php
    public static function parse(Parser $parser, TokensList $list, array $options = []): Key
    {
        $ret = new Key();

        /**
         * Last parsed column.
         */
        $lastColumn = [];

        /**
         * The state of the parser.
         *
         * Below are the states of the parser.
         *
         *      0 ---------------------[ type ]---------------------------> 1
         *
         *      1 ---------------------[ name ]---------------------------> 1
         *      1 ---------------------[ columns ]------------------------> 2
         *      1 ---------------------[ expression ]---------------------> 5
         *
         *      2 ---------------------[ column length ]------------------> 3
         *      3 ---------------------[ column length ]------------------> 2
         *      2 ---------------------[ options ]------------------------> 4
         *      5 ---------------------[ expression ]---------------------> 4
         */
        $state = 0;

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

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

            // Skipping whitespaces and comments.
            if (($token->type === TokenType::Whitespace) || ($token->type === TokenType::Comment)) {
                continue;
            }

            if ($state === 0) {
                $ret->type = $token->value;
                $state = 1;
            } elseif ($state === 1) {
                if (($token->type === TokenType::Operator) && ($token->value === '(')) {
                    $positionBeforeSearch = $list->idx;
                    $list->idx++;// Ignore the current token "(" or the search condition will always be true
                    $nextToken = $list->getNext();
                    $list->idx = $positionBeforeSearch;// Restore the position

                    if ($nextToken !== null && $nextToken->value === '(') {
                        // Switch to expression mode
                        $state = 5;
                    } else {
                        $state = 2;
                    }
                } else {
                    $ret->name = $token->value;
                }
            } elseif ($state === 2) {
                if ($token->type === TokenType::Operator) {
                    if ($token->value === '(') {
                        $state = 3;
                    } elseif (($token->value === ',') || ($token->value === ')')) {
                        $state = $token->value === ',' ? 2 : 4;
                        if ($lastColumn !== []) {
                            $ret->columns[] = $lastColumn;
                            $lastColumn = [];
                        }
                    }
                } elseif (
                    (
                        $token->type === TokenType::Keyword
                    )
                    &&
                    (
                        ($token->keyword === 'ASC') || ($token->keyword === 'DESC')
                    )
                ) {
                    $lastColumn['order'] = $token->keyword;
                } else {
                    $lastColumn['name'] = $token->value;
                }
            } elseif ($state === 3) {
                if (($token->type === TokenType::Operator) && ($token->value === ')')) {
                    $state = 2;
                } else {
                    $lastColumn['length'] = $token->value;
                }
            } elseif ($state === 4) {
                $ret->options = OptionsArrays::parse($parser, $list, self::KEY_OPTIONS);
                ++$list->idx;
                break;
            } elseif ($state === 5) {
                if ($token->type === TokenType::Operator) {
                    // This got back to here and we reached the end of the expression
                    if ($token->value === ')') {
                        $state = 4;// go back to state 4 to fetch options
                        continue;
                    }

                    // The expression is not finished, adding a separator for the next expression
                    if ($token->value === ',') {
                        $ret->expr .= ', ';
                        continue;
                    }

                    // Start of the expression
                    if ($token->value === '(') {
                        // This is the first expression, set to empty
                        if ($ret->expr === null) {
                            $ret->expr = '';
                        }

                        $ret->expr .= Expressions::parse($parser, $list, ['parenthesesDelimited' => true]);
                        continue;
                    }
                    // Another unexpected operator was found
                }

                // Something else than an operator was found
                $parser->error('Unexpected token.', $token);
            }
        }

        --$list->idx;

        return $ret;
    }