<?php
/**
 * Copyright © 2016 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Setup\Module\I18n\Parser\Adapter\Php;

/**
 * Tokenizer
 */
class Tokenizer
{
    /**
     * Tokens
     *
     * @var array
     */
    private $_tokens = [];

    /**
     * Tokens count
     *
     * @var int
     */
    private $_tokensCount;

    /**
     * Open brackets
     *
     * @var int
     */
    private $_openBrackets;

    /**
     * Close brackets
     *
     * @var int
     */
    private $_closeBrackets;

    /**
     * Parse given file
     *
     * @param string $filePath
     * @return void
     */
    public function parse($filePath)
    {
        $this->_tokens = token_get_all(file_get_contents($filePath));
        $this->_tokensCount = count($this->_tokens);
    }

    /**
     * Checks if the next set of tokens is a valid class identifier and it matches passed class name
     *
     * @param string $className
     * @return bool
     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
     */
    public function isMatchingClass($className)
    {
        /*
         * 1 - beginning, class identifier can begin either with identifier or with namespace separator
         * 2 - after namespace separator, identifier is expected
         * 3 - after identifier, namespace separator or open brace is expected
         * 4 - ending, tells that class identifier is valid
         */
        $state = 1;
        $classString = '';
        while ($token = $this->getNextRealToken()) {
            if ($token->isNamespaceSeparator() && $state != 2) {
                $classString .= $token->getValue();
                $state = 2;
            } elseif ($token->isIdentifier() && $state != 3) {
                $classString .= $token->getValue();
                $state = 3;
            } elseif ($token->isOpenBrace() && $state == 3) {
                $state = 4;
                break;
            } else {
                return false;
            }
        }
        if ($state == 4 && $className == substr($classString, -strlen($className))) {
            return true;
        }
        return false;
    }

    /**
     * Get arguments tokens of function
     *
     * @return array
     */
    public function getFunctionArgumentsTokens()
    {
        $arguments = [];
        try {
            $this->_openBrackets = 1;
            $this->_closeBrackets = 0;
            $argumentNumber = 0;
            while (true) {
                $token = $this->getNextToken();
                if ($token->isSemicolon()) {
                    break;
                }
                if ($token->isOpenBrace()) {
                    $this->_skipInnerArgumentInvoke();
                    continue;
                }
                if ($token->isCloseBrace()) {
                    $this->_closeBrackets++;
                }
                $arguments[$argumentNumber][] = $token;
                if ($token->isComma() && $this->_isInnerArgumentClosed()) {
                    array_pop($arguments[$argumentNumber]);
                    $argumentNumber++;
                }
                if ($this->_openBrackets == $this->_closeBrackets) {
                    break;
                }
            }
        } catch (\Exception $e) {
            return [];
        }
        return $arguments;
    }

    /**
     * Whenever inner argument closed
     *
     * @return bool
     */
    private function _isInnerArgumentClosed()
    {
        return $this->_openBrackets - 1 == $this->_closeBrackets;
    }

    /**
     * Skip invoke the inner argument of function
     *
     * @return void
     */
    private function _skipInnerArgumentInvoke()
    {
        $this->_openBrackets++;
        while (!$this->getNextToken()->isCloseBrace()) {
            if ($this->getCurrentToken()->isCloseBrace()) {
                $this->_closeBrackets++;
            }
            if ($this->getCurrentToken()->isOpenBrace()) {
                $this->_openBrackets++;
            }
        }
        $this->_closeBrackets++;
    }

    /**
     * Get current token
     *
     * @return \Magento\Setup\Module\I18n\Parser\Adapter\Php\Tokenizer\Token
     */
    public function getCurrentToken()
    {
        return $this->_createToken(current($this->_tokens));
    }

    /**
     * Get next token
     *
     * @return bool|\Magento\Setup\Module\I18n\Parser\Adapter\Php\Tokenizer\Token
     */
    public function getNextToken()
    {
        return ($token = next($this->_tokens)) ? $this->_createToken($token) : false;
    }

    /**
     * Get next token skipping all whitespaces
     *
     * @return \Magento\Setup\Module\I18n\Parser\Adapter\Php\Tokenizer\Token|false
     */
    public function getNextRealToken()
    {
        do {
            $token = $this->getNextToken();
        } while ($token && $token->isWhitespace());
        return $token;
    }

    /**
     * Check if it is end of loop
     *
     * @return bool
     */
    public function isEndOfLoop()
    {
        return key($this->_tokens) === null;
    }

    /**
     * Create token from array|string
     *
     * @param array|string $tokenData
     * @return \Magento\Setup\Module\I18n\Parser\Adapter\Php\Tokenizer\Token
     */
    private function _createToken($tokenData)
    {
        if (is_array($tokenData)) {
            return new Tokenizer\Token($tokenData[0], $tokenData[1], $tokenData[2]);
        } else {
            return new Tokenizer\Token($tokenData, $tokenData);
        }
    }
}