PhpMyAdmin\SqlParser\Components\AlterOperation::parse()

Complexity

Conditions	53
Paths	44

Size

Total Lines	221
Code Lines	115

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	115
CRAP Score	53

Importance

Changes	2
Bugs	0	Features	0

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

        /**
         * Counts brackets.
         *
         * @var int
         */
        $brackets = 0;

        /**
         * The state of the parser.
         *
         * Below are the states of the parser.
         *
         *      0 ---------------------[ options ]---------------------> 1
         *
         *      1 ----------------------[ field ]----------------------> 2
         *
         *      1 -------------[ PARTITION / PARTITION BY ]------------> 3
         *
         *      2 -------------------------[ , ]-----------------------> 0
         *
         * @var int
         */
        $state = 0;

        /**
         * partition state.
         *
         * @var int
         */
        $partitionState = 0;

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

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

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

            // Skipping whitespaces.
            if ($token->type === Token::TYPE_WHITESPACE) {
                if ($state === 2) {
                    // When parsing the unknown part, the whitespaces are
                    // included to not break anything.
                    $ret->unknown[] = $token;
                    continue;
                }
            }

            if ($state === 0) {
                $ret->options = OptionsArray::parse($parser, $list, $options);

                // Not only when aliasing but also when parsing the body of an event, we just list the tokens of the
                // body in the unknown tokens list, as they define their own statements.
                if ($ret->options->has('AS') || $ret->options->has('DO')) {
                    for (; $list->idx < $list->count; ++$list->idx) {
                        if ($list->tokens[$list->idx]->type === Token::TYPE_DELIMITER) {
                            break;
                        }

                        $ret->unknown[] = $list->tokens[$list->idx];
                    }

                    break;
                }

                $state = 1;
                if ($ret->options->has('PARTITION') || $token->value === 'PARTITION BY') {
                    $state = 3;
                    $list->getPrevious(); // in order to check whether it's partition or partition by.
                }
            } elseif ($state === 1) {
                $ret->field = Expression::parse(
                    $parser,
                    $list,
                    [
                        'breakOnAlias' => true,
                        'parseField' => 'column',
                    ]
                );
                if ($ret->field === null) {
                    // No field was read. We go back one token so the next
                    // iteration will parse the same token, but in state 2.
                    --$list->idx;
                }

                // If the operation is a RENAME COLUMN, now we have detected the field to rename, we need to parse
                // again the options to get the new name of the column.
                if ($ret->options->has('RENAME') && $ret->options->has('COLUMN')) {
                    $nextOptions = OptionsArray::parse($parser, $list, $options);
                    $ret->options->merge($nextOptions);
                }

                $state = 2;
            } elseif ($state === 2) {
                if (is_string($token->value) || is_numeric($token->value)) {
                    $arrayKey = $token->value;
                } else {
                    $arrayKey = $token->token;
                }

                if ($token->type === Token::TYPE_OPERATOR) {
                    if ($token->value === '(') {
                        ++$brackets;
                    } elseif ($token->value === ')') {
                        --$brackets;
                    } elseif (($token->value === ',') && ($brackets === 0)) {
                        break;
                    }
                } elseif (! self::checkIfTokenQuotedSymbol($token)) {
                    // If the current token is "SET" or "ENUM", we want to avoid the token between their parenthesis in
                    // the unknown tokens.
                    if (in_array($token->value, ['SET', 'ENUM'], true)) {
                        $list->idx++; // Ignore the current token
                        $nextToken = $list->getNext();

                        if ($nextToken !== null && $nextToken->value === '(') {
                            $list->getNextOfTypeAndValue(Token::TYPE_OPERATOR, ')');
                        } elseif ($nextToken !== null && $nextToken->value === 'DEFAULT') {
                            // to avoid adding the `DEFAULT` token to the unknown tokens.
                            ++$list->idx;
                        } else {
                            $parser->error(
                                'A new statement was found, but no delimiter between it and the previous one.',
                                $token
                            );
                            break;
                        }
                    } elseif (! empty(Parser::$statementParsers[$token->value])) {
                        // We have reached the end of ALTER operation and suddenly found
                        // a start to new statement, but have not found a delimiter between them
                        $parser->error(
                            'A new statement was found, but no delimiter between it and the previous one.',
                            $token
                        );
                        break;
                    } elseif (
                        (array_key_exists($arrayKey, self::$databaseOptions)
                        || array_key_exists($arrayKey, self::$tableOptions))
                        && ! self::checkIfColumnDefinitionKeyword($arrayKey)
                    ) {
                        // This alter operation has finished, which means a comma
                        // was missing before start of new alter operation
                        $parser->error('Missing comma before start of a new alter operation.', $token);
                        break;
                    }
                }

                $ret->unknown[] = $token;
            } elseif ($state === 3) {
                if ($partitionState === 0) {
                    $list->idx++; // Ignore the current token
                    $nextToken = $list->getNext();
                    if (
                        ($token->type === Token::TYPE_KEYWORD)
                        && (($token->keyword === 'PARTITION BY')
                        || ($token->keyword === 'PARTITION' && $nextToken && $nextToken->value !== '('))
                    ) {
                        $partitionState = 1;
                    } elseif (($token->type === Token::TYPE_KEYWORD) && ($token->keyword === 'PARTITION')) {
                        $partitionState = 2;
                    }

                    --$list->idx; // to decrease the idx by one, because the last getNext returned and increased it.

                    // reverting the effect of the getNext
                    $list->getPrevious();
                    $list->getPrevious();

                    ++$list->idx; // to index the idx by one, because the last getPrevious returned and decreased it.
                } elseif ($partitionState === 1) {
                    // Fetch the next token in a way the current index is reset to manage whitespaces in "field".
                    $currIdx = $list->idx;
                    ++$list->idx;
                    $nextToken = $list->getNext();
                    $list->idx = $currIdx;
                    // Building the expression used for partitioning.
                    if (empty($ret->field)) {
                        $ret->field = '';
                    }

                    if (
                        $token->type === Token::TYPE_OPERATOR
                        && $token->value === '('
                        && $nextToken
                        && $nextToken->keyword === 'PARTITION'
                    ) {
                        $partitionState = 2;
                        --$list->idx; // Current idx is on "(". We need a step back for ArrayObj::parse incoming.
                    } else {
                        $ret->field .= $token->type === Token::TYPE_WHITESPACE ? ' ' : $token->token;
                    }
                } elseif ($partitionState === 2) {
                    $ret->partitions = ArrayObj::parse(
                        $parser,
                        $list,
                        ['type' => PartitionDefinition::class]
                    );
                }
            }
        }

        if ($ret->options->isEmpty()) {
            $parser->error('Unrecognized alter operation.', $list->tokens[$list->idx]);
        }

        --$list->idx;

        return $ret;
    }