<?php

/*
 *  $Id: ReplaceTokens.php 325 2007-12-20 15:44:58Z hans $  
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information please see
 * <http://phing.info>.
*/

include_once 'phing/filters/BaseParamFilterReader.php';
include_once 'phing/types/TokenSource.php';
include_once 'phing/filters/ChainableReader.php';

/*
 * Replaces tokens in the original input with user-supplied values.
 *
 * Example:
 *
 * <pre><replacetokens begintoken="#" endtoken="#">;
 *   <token key="DATE" value="${TODAY}"/>
 * </replacetokens></pre>
 *
 * Or:
 *
 * <pre><filterreader classname="phing.filters.ReplaceTokens">
 *   <param type="tokenchar" name="begintoken" value="#"/>
 *   <param type="tokenchar" name="endtoken" value="#"/>
 *   <param type="token" name="DATE" value="${TODAY}"/>
 * </filterreader></pre>
 *
 * @author    <a href="mailto:yl@seasonfive.com">Yannick Lecaillez</a>
 * @author    hans lellelid, hans@velum.net
 * @version   $Revision: 1.14 $ $Date: 2007-12-20 16:44:58 +0100 (Thu, 20 Dec 2007) $
 * @access    public
 * @see       BaseParamFilterReader
 * @package   phing.filters
 */
class ReplaceTokens extends BaseParamFilterReader implements ChainableReader {

    /**
     * Default "begin token" character.
     * @var string
     */
    const DEFAULT_BEGIN_TOKEN = "@";

    /**
     * Default "end token" character.
     * @var string
     */
    const DEFAULT_END_TOKEN = "@";

    /**
     * [Deprecated] Data that must be read from, if not null.
     * @var string
     */
    private    $_queuedData = null;

    /**
     * Array to hold the replacee-replacer pairs (String to String).
     * @var array
     */
    private $_tokens = array();

    /**
     * Array to hold the token sources that make tokens from
     * different sources available
     * @var array
     */
    private $_tokensources = array();

    /**
     * Array holding all tokens given directly to the Filter and
     * those passed via a TokenSource.
     * @var array
     */
    private $_alltokens = null;

    /**
     * Character marking the beginning of a token.
     * @var string
     */
    private    $_beginToken = "@";  // self::DEFAULT_BEGIN_TOKEN;

    /**
     * Character marking the end of a token.
     * @var string
     */
    private    $_endToken = "@"; //self::DEFAULT_END_TOKEN;

    /**
     * Performs lookup on key and returns appropriate replacement string.
     * @param array $matches Array of 1 el containing key to search for.
     * @return string     Text with which to replace key or value of key if none is found.
     * @access private
     */
    private function replaceTokenCallback($matches) {
                
        $key = $matches[1];
        
        /* Get tokens from tokensource and merge them with the
         * tokens given directly via build file. This should be 
         * done a bit more elegantly
         */
        if ($this->_alltokens === null) {
            $this->_alltokens = array();

            $count = count($this->_tokensources);
            for ($i = 0; $i < $count; $i++) {
                $source = $this->_tokensources[$i];
                $this->_alltokens = array_merge($this->_alltokens, $source->getTokens());
            }


            $this->_alltokens = array_merge($this->_tokens, $this->_alltokens);
        }

        $tokens = $this->_alltokens;

        $replaceWith = null;
        $count = count($tokens);

        for ($i = 0; $i < $count; $i++) {
            if ($tokens[$i]->getKey() === $key) {
                $replaceWith = $tokens[$i]->getValue();
            }
        }

        if ($replaceWith === null) {
            $replaceWith = $this->_beginToken . $key . $this->_endToken;            
            $this->log("No token defined for key \"".$this->_beginToken  . $key . $this->_endToken."\"");
        } else {
            $this->log("Replaced \"".$this->_beginToken  . $key . $this->_endToken ."\" with \"".$replaceWith."\"");
        }

        return $replaceWith;
    }

    /**
     * Returns stream with tokens having been replaced with appropriate values.
     * If a replacement value is not found for a token, the token is left in the stream.
     * 
     * @return mixed filtered stream, -1 on EOF.
     */
    function read($len = null) {
        if ( !$this->getInitialized() ) {
            $this->_initialize();
            $this->setInitialized(true);
        }

        // read from next filter up the chain
        $buffer = $this->in->read($len);

        if($buffer === -1) {
            return -1;
        }    
        
        // filter buffer
        $buffer = preg_replace_callback(
            "/".preg_quote($this->_beginToken)."([\w\.\-:]+?)".preg_quote($this->_endToken)."/",
            array($this, 'replaceTokenCallback'), $buffer);

        return $buffer;
    }
   
    /**
     * Sets the "begin token" character.
     * 
     * @param string $beginToken the character used to denote the beginning of a token.
     */
    function setBeginToken($beginToken) {
        $this->_beginToken = (string) $beginToken;
    }

    /**
     * Returns the "begin token" character.
     * 
     * @return string The character used to denote the beginning of a token.
     */
    function getBeginToken() {
        return $this->_beginToken;
    }

    /**
     * Sets the "end token" character.
     * 
     * @param string $endToken the character used to denote the end of a token
     */
    function setEndToken($endToken) {
        $this->_endToken = (string) $endToken;
    }

    /**
     * Returns the "end token" character.
     * 
     * @return the character used to denote the beginning of a token
     */
    function getEndToken() {
        return $this->_endToken;
    }

    /**
     * Adds a token element to the map of tokens to replace.
     * 
     * @return object The token added to the map of replacements.
     *               Must not be <code>null</code>.
     */
    function createToken() {
        $num = array_push($this->_tokens, new Token());
        return $this->_tokens[$num-1];
    }
    
    /**
     * Adds a token source to the sources of this filter.
     *
     * @return  object  A Reference to the source just added.
     */
    function createTokensource() {
        $num = array_push($this->_tokensources, new TokenSource());
        return $this->_tokensources[$num-1];
    }

    /**
     * Sets the map of tokens to replace.
     * ; used by ReplaceTokens::chain()
     *
     * @param array A map (String->String) of token keys to replacement
     *              values. Must not be <code>null</code>.
     */
    function setTokens($tokens) {
        // type check, error must never occur, bad code of it does
        if ( !is_array($tokens) ) {
            throw new Exception("Excpected 'array', got something else");
        }

        $this->_tokens = $tokens;
    }

    /**
     * Returns the map of tokens which will be replaced.
     * ; used by ReplaceTokens::chain()
     *
     * @return array A map (String->String) of token keys to replacement values.
     */
    function getTokens() {
        return $this->_tokens;
    }

    /**
     * Sets the tokensources to use; used by ReplaceTokens::chain()
     * 
     * @param   array   An array of token sources.
     */ 
    function setTokensources($sources) {
        // type check
        if ( !is_array($sources)) {
            throw new Exception("Exspected 'array', got something else");
        }
        $this->_tokensources = $sources;
    }

    /**
     * Returns the token sources used by this filter; used by ReplaceTokens::chain()
     * 
     * @return  array
     */
    function getTokensources() {
        return $this->_tokensources;
    }

    /**
     * Creates a new ReplaceTokens using the passed in
     * Reader for instantiation.
     * 
     * @param object A Reader object providing the underlying stream.
     *               Must not be <code>null</code>.
     * 
     * @return object A new filter based on this configuration, but filtering
     *         the specified reader
     */
    function chain(Reader $reader) {
        $newFilter = new ReplaceTokens($reader);
        $newFilter->setProject($this->getProject());
        $newFilter->setBeginToken($this->getBeginToken());
        $newFilter->setEndToken($this->getEndToken());
        $newFilter->setTokens($this->getTokens());
        $newFilter->setTokensources($this->getTokensources());
        $newFilter->setInitialized(true);
        return $newFilter;
    }

    /**
     * Initializes tokens and loads the replacee-replacer hashtable.
     * This method is only called when this filter is used through
     * a <filterreader> tag in build file.
     */
    private function _initialize() {
        $params = $this->getParameters();
        if ( $params !== null ) {
            for($i = 0 ; $i<count($params) ; $i++) {
                if ( $params[$i] !== null ) {
                    $type = $params[$i]->getType();
                    if ( $type === "tokenchar" ) {
                        $name = $params[$i]->getName();
                        if ( $name === "begintoken" ) {
                            $this->_beginToken = substr($params[$i]->getValue(), 0, 1);
                        } else if ( $name === "endtoken" ) {
                            $this->_endToken = substr($params[$i]->getValue(), 0, 1);
                        }
                    } else if ( $type === "token" ) {
                        $name  = $params[$i]->getName();
                        $value = $params[$i]->getValue();

                        $tok = new Token();
                        $tok->setKey($name);
                        $tok->setValue($value);

                        array_push($this->_tokens, $tok);
                    } else if ( $type === "tokensource" ) {
                        // Store data from nested tags in local array
                        $arr = array(); $subparams = $params[$i]->getParams();
                        $count = count($subparams);
                        for ($i = 0; $i < $count; $i++)  {
                            $arr[$subparams[$i]->getName()] = $subparams[$i]->getValue();
                        }

                        // Create TokenSource
                        $tokensource = new TokenSource();
                        if (isset($arr["classname"])) 
                            $tokensource->setClassname($arr["classname"]);

                        // Copy other parameters 1:1 to freshly created TokenSource
                        foreach ($arr as $key => $value) {
                            if (strtolower($key) === "classname")
                                continue;
                            $param = $tokensource->createParam();
                            $param->setName($key);
                            $param->setValue($value);
                        }

                        $this->_tokensources[] = $tokensource;
                    }
                }
            }
        }
    }
}

/**
 * Holds a token.
 */
class Token {

    /**
     * Token key.
     * @var string
     */
    private $_key;

    /**
     * Token value.
     * @var string
     */
    private $_value;

    /**
     * Sets the token key.
     * 
     * @param string $key The key for this token. Must not be <code>null</code>.
     */
    function setKey($key) {
        $this->_key = (string) $key;
    }

    /**
     * Sets the token value.
     * 
     * @param string $value The value for this token. Must not be <code>null</code>.
     */
    function setValue($value) {
        $this->_value = (string) $value;
    }

    /**
     * Returns the key for this token.
     * 
     * @return string The key for this token.
     */
    function getKey() {
        return $this->_key;
    }

    /**
     * Returns the value for this token.
     * 
     * @return string The value for this token.
     */
    function getValue() {
        return $this->_value;
    }
}


