<?php
/**
 * Generic_Sniffs_PHP_ForbiddenFunctionsSniff.
 *
 * PHP version 5
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006-2014 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   https://github.com/squizlabs/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */

/**
 * Generic_Sniffs_PHP_ForbiddenFunctionsSniff.
 *
 * Discourages the use of alias functions that are kept in PHP for compatibility
 * with older versions. Can be used to forbid the use of any function.
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006-2014 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   https://github.com/squizlabs/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
 * @version   Release: @package_version@
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */
class Generic_Sniffs_PHP_ForbiddenFunctionsSniff implements PHP_CodeSniffer_Sniff
{

    /**
     * A list of forbidden functions with their alternatives.
     *
     * The value is NULL if no alternative exists. IE, the
     * function should just not be used.
     *
     * @var array(string => string|null)
     */
    protected $forbiddenFunctions = array(
                                     'sizeof' => 'count',
                                     'delete' => 'unset',
                                    );

    /**
     * A cache of forbidden function names, for faster lookups.
     *
     * @var array(string)
     */
    protected $forbiddenFunctionNames = array();

    /**
     * If true, forbidden functions will be considered regular expressions.
     *
     * @var bool
     */
    protected $patternMatch = false;

    /**
     * If true, an error will be thrown; otherwise a warning.
     *
     * @var bool
     */
    public $error = true;


    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array
     */
    public function register()
    {
        // Everyone has had a chance to figure out what forbidden functions
        // they want to check for, so now we can cache out the list.
        $this->forbiddenFunctionNames = array_keys($this->forbiddenFunctions);

        if ($this->patternMatch === true) {
            foreach ($this->forbiddenFunctionNames as $i => $name) {
                $this->forbiddenFunctionNames[$i] = '/'.$name.'/i';
            }
        }

        return array(T_STRING);

    }//end register()


    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
     * @param int                  $stackPtr  The position of the current token in
     *                                        the stack passed in $tokens.
     *
     * @return void
     */
    public function process(PHP_CodeSniffer_File $phpcsFile, $stackPtr)
    {
        $tokens = $phpcsFile->getTokens();

        $ignore = array(
                   T_DOUBLE_COLON,
                   T_OBJECT_OPERATOR,
                   T_FUNCTION,
                   T_CONST,
                   T_PUBLIC,
                   T_PRIVATE,
                   T_PROTECTED,
                   T_AS,
                   T_NEW,
                   T_INSTEADOF,
                   T_NS_SEPARATOR,
                   T_IMPLEMENTS,
                  );

        $prevToken = $phpcsFile->findPrevious(T_WHITESPACE, ($stackPtr - 1), null, true);

        // If function call is directly preceded by a NS_SEPARATOR it points to the
        // global namespace, so we should still catch it.
        if ($tokens[$prevToken]['code'] === T_NS_SEPARATOR) {
            $prevToken = $phpcsFile->findPrevious(T_WHITESPACE, ($prevToken - 1), null, true);
            if ($tokens[$prevToken]['code'] === T_STRING) {
                // Not in the global namespace.
                return;
            }
        }

        if (in_array($tokens[$prevToken]['code'], $ignore) === true) {
            // Not a call to a PHP function.
            return;
        }

        $nextToken = $phpcsFile->findNext(T_WHITESPACE, ($stackPtr + 1), null, true);
        if (in_array($tokens[$nextToken]['code'], $ignore) === true) {
            // Not a call to a PHP function.
            return;
        }

        $function = strtolower($tokens[$stackPtr]['content']);
        $pattern  = null;

        if ($this->patternMatch === true) {
            $count   = 0;
            $pattern = preg_replace(
                $this->forbiddenFunctionNames,
                $this->forbiddenFunctionNames,
                $function,
                1,
                $count
            );

            if ($count === 0) {
                return;
            }

            // Remove the pattern delimiters and modifier.
            $pattern = substr($pattern, 1, -2);
        } else {
            if (in_array($function, $this->forbiddenFunctionNames) === false) {
                return;
            }
        }

        $this->addError($phpcsFile, $stackPtr, $function, $pattern);

    }//end process()


    /**
     * Generates the error or warning for this sniff.
     *
     * @param PHP_CodeSniffer_File $phpcsFile The file being scanned.
     * @param int                  $stackPtr  The position of the forbidden function
     *                                        in the token array.
     * @param string               $function  The name of the forbidden function.
     * @param string               $pattern   The pattern used for the match.
     *
     * @return void
     */
    protected function addError($phpcsFile, $stackPtr, $function, $pattern=null)
    {
        $data  = array($function);
        $error = 'The use of function %s() is ';
        if ($this->error === true) {
            $type   = 'Found';
            $error .= 'forbidden';
        } else {
            $type   = 'Discouraged';
            $error .= 'discouraged';
        }

        if ($pattern === null) {
            $pattern = $function;
        }

        if ($this->forbiddenFunctions[$pattern] !== null) {
            $type  .= 'WithAlternative';
            $data[] = $this->forbiddenFunctions[$pattern];
            $error .= '; use %s() instead';
        }

        if ($this->error === true) {
            $phpcsFile->addError($error, $stackPtr, $type, $data);
        } else {
            $phpcsFile->addWarning($error, $stackPtr, $type, $data);
        }

    }//end addError()


}//end class

?>
