<?php
/**
 * Generic_Sniffs_PHP_LowerCaseConstantSniff.
 *
 * PHP version 5
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   http://matrix.squiz.net/developer/tools/php_cs/licence BSD Licence
 * @version   CVS: $Id: LowerCaseConstantSniff.php,v 1.8 2008/02/18 00:01:06 squiz Exp $
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */

/**
 * Generic_Sniffs_PHP_LowerCaseConstantSniff.
 *
 * Checks that all uses of true, false and null are lowerrcase.
 *
 * @category  PHP
 * @package   PHP_CodeSniffer
 * @author    Greg Sherwood <gsherwood@squiz.net>
 * @author    Marc McIntyre <mmcintyre@squiz.net>
 * @copyright 2006 Squiz Pty Ltd (ABN 77 084 670 600)
 * @license   http://matrix.squiz.net/developer/tools/php_cs/licence BSD Licence
 * @version   Release: 1.2.0a1
 * @link      http://pear.php.net/package/PHP_CodeSniffer
 */
class PhpHatesMe_Sniffs_Variables_UnitializedVariableSniff implements PHP_CodeSniffer_Sniff
{

    private $tokens = array( );

    /**
     * A list of tokenizers this sniff supports.
     *
     * @var array
     */
    public $supportedTokenizers = array(
                                   'PHP'                                   
                                  );

    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array
     */
    public function register()
    {
        return array(
                T_FUNCTION
               );

    }//end register()

    private function isAlwaysDefined( $stackPtr )
    {
    	if ( $this->tokens[$stackPtr]['content'] == '$this' ) {
    		return true;
    	} 
    	
    	if( $this->isSuperGlobal( $stackPtr ) ) {
			return true;
		}

		if ( $this->isStaticVar( $stackPtr ) ) {
			return true;
		}
		
		return false;
    }
    
    private function isDefinition( $i )
    {
    	if ( $this->isForeachAsVar( $i ) ) {
    		return true;
    	}
    	
    	if ( $this->isForeachAsValueVar( $i ) ) {
    		return true;
    	}
    	
    	if ( $this->isGlobalVar( $i ) ) {
    		return true;
    	}

	if ( $this->isListFunction( $i ) ) {
		return true;
	}

    	return false;
    }

    private function isListFunction( $stackPtr )
    {
	$unimportantTokens = array( T_WHITESPACE, T_COMMENT, T_COMMA, T_OPEN_CURLY_BRACKET, T_OPEN_PARENTHESIS, T_VARIABLE );
        $currentPointer = $stackPtr - 1;
        while( isset( $this->tokens[$currentPointer] ) ) {
 	       if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
			return $this->tokens[$currentPointer]['code'] == T_LIST;
	        }
               $currentPointer--;
        }
        return false;
    }
    
	private function setTokens( PHP_CodeSniffer_File $phpcsFile )
	{
		$this->tokens = $phpcsFile->getTokens( );
	}
	
    /**
     * Processes this sniff, 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)
    {
    	static $lastStackPtr;
		if ( $lastStackPtr == $stackPtr ) return;
	
		$this->setTokens( $phpcsFile );
		$tokens = $this->tokens;
	
		$functionToken = $this->tokens[$stackPtr];
	
		$initializedVars = $this->getParameter( $this->tokens, $stackPtr );
	
		// no body if it's an interface
		if ( !isset( $functionToken['scope_opener'] ) ) {
			return;
		}
	
		for( $i = $functionToken['scope_opener']; $i <= $functionToken['scope_closer']; $i++ ) {
			$currentToken = $this->tokens[$i];
			if ( $currentToken['code'] == T_VARIABLE ) {
				if ( $this->isAlwaysDefined( $i ) ) {
					continue;
				}
				
				if ( $this->isDefinition( $i ) ) {
					$initializedVars[] = $currentToken['content'];
					continue;
				}
				
				$nextToken = $this->getNextExecutingToken( $this->tokens, $i );

				if ( $nextToken['code'] == T_EQUAL ) {
					$initializedVars[] = $currentToken['content'];
				}else{
					if ( !in_array( $currentToken['content'], $initializedVars ) ) {
						$error = 'Undefined variable: '.$currentToken['content'].'.';
						$phpcsFile->addError($error, $i);
					}
				}
			}
		}
		$lastStackPtr = $stackPtr;
    }
    

    private function isForeachAsValueVar( $stackPtr )
    {
        $this->tokens = $this->tokens;
        $unimportantTokens = array( T_WHITESPACE, T_COMMENT );
        $this->tokens = $this->tokens;
        $currentPointer = $stackPtr - 1;
        while( isset( $this->tokens[$currentPointer] ) ) {
	        if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
		        return $this->tokens[$currentPointer]['code'] == T_DOUBLE_ARROW;
		}
	        $currentPointer--;
		}
		return false;
    }
    

    private function isSuperGlobal( $stackPtr )
    {
		$superGlobals = array( '$_POST', '$_GET', '$_REQUEST', '$_SERVER', '$_COOKIE', '$_ENV', '$_SESSION', '$_FILES' );
		$token = $this->tokens[$stackPtr];
		return in_array( $token['content'], $superGlobals );
    }
    

    private function isForeachAsVar( $stackPtr )
    {
    	$this->tokens = $this->tokens;
        $unimportantTokens = array( T_WHITESPACE, T_COMMENT );
        $this->tokens = $this->tokens;
        $currentPointer = $stackPtr - 1;
		while( isset( $this->tokens[$currentPointer] ) ) {
	        if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
				return $this->tokens[$currentPointer]['code'] == T_AS;
			}
			$currentPointer--;	
		}
		return false;
    }
    

    private function isStaticVar( $stackPtr )
    {
		$unimportantTokens = array( T_WHITESPACE, T_COMMENT, T_DOUBLE_COLON );
		$this->tokens = $this->tokens;
		$currentPointer = $stackPtr - 1;
		while( isset( $this->tokens[$currentPointer] ) ) {
			if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
				return $this->tokens[$currentPointer]['code'] == T_SELF;
		        }
	                $currentPointer--;
		}
		return false;
    }
    
									  
    private function isGlobalVar( $stackPtr )
    {
		$unimportantTokens = array( T_WHITESPACE, T_COMMENT, T_COMMA, T_VARIABLE );
    	$this->tokens = $this->tokens;
		$currentPointer = $stackPtr - 1;
		while( isset( $this->tokens[$currentPointer] ) ) {
        	if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
				return $this->tokens[$currentPointer]['code'] == T_GLOBAL;
	        }
	        $currentPointer--;
		}										        
		return false;
    }
    
   
    private function getParameter( $tokens, $stackPtr )
    {
    	$parameters = array( );
    	$currentToken = $this->tokens[$stackPtr];
    	for( $i = $currentToken['parenthesis_opener']; $i < $currentToken['parenthesis_closer']; $i++ ) {
			if ( $this->tokens[$i]['code'] == T_VARIABLE ) {
				$parameters[] = $this->tokens[$i]['content'];
			}
		}
		return $parameters;
    }
    

    private function getNextExecutingToken( $tokens, $stackPtr ) 
    {
    	$unimportantTokens = array( T_WHITESPACE, 
								    T_COMMENT, 
								    T_OPEN_SQUARE_BRACKET, 
								    T_CLOSE_SQUARE_BRACKET, 
								    T_STRING, 
								    T_CONSTANT_ENCAPSED_STRING, 
								    T_VARIABLE );
								    
		$currentPointer = $stackPtr + 1;
		while( isset( $this->tokens[$currentPointer] ) ) {
			if ( !in_array( $this->tokens[$currentPointer]['code'], $unimportantTokens ) ) {
				return $this->tokens[$currentPointer];
			}
			$currentPointer++;
		}
    }
}
?>