<?php
/*
 *  $Id: Path.php 359 2008-02-26 09:16:23Z mrook $
 *
 * 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>. 
 */

require_once 'phing/types/DataType.php';
include_once 'phing/util/PathTokenizer.php';
include_once 'phing/types/FileSet.php';

/**
 * This object represents a path as used by include_path or PATH
 * environment variable.
 *
 * This class has been adopted from the Java Ant equivalent.  The ability have
 * path structures in Phing is important; however, because of how PHP classes interact
 * the ability to specify CLASSPATHs makes less sense than Java.Rather than providing
 * CLASSPATH for any tasks that take classes as parameters, perhaps a better
 * solution in PHP is to have an IncludePath task, which prepends paths to PHP's include_path
 * INI variable. This gets around the problem that simply using a path to load the initial
 * PHP class is not enough (in most cases the loaded class may assume that it is on the global
 * PHP include_path, and will try to load dependent classes accordingly).  The other option is
 * to provide a way for this class to add paths to the include path, if desired -- or to create
 * an IncludePath subclass.  Once added, though, when would a path be removed from the include path?
 * 
 * <p>
 * <code>
 * &lt;sometask&gt;<br>
 * &nbsp;&nbsp;&lt;somepath&gt;<br>
 * &nbsp;&nbsp;&nbsp;&nbsp;&lt;pathelement location="/path/to/file" /&gt;<br>
 * &nbsp;&nbsp;&nbsp;&nbsp;&lt;pathelement path="/path/to/class2;/path/to/class3" /&gt;<br>
 * &nbsp;&nbsp;&nbsp;&nbsp;&lt;pathelement location="/path/to/file3" /&gt;<br>
 * &nbsp;&nbsp;&lt;/somepath&gt;<br>
 * &lt;/sometask&gt;<br>
 * </code>
 * <p>
 * The object implemention <code>sometask</code> must provide a method called
 * <code>createSomepath</code> which returns an instance of <code>Path</code>.
 * Nested path definitions are handled by the Path object and must be labeled
 * <code>pathelement</code>.<p>
 *
 * The path element takes a parameter <code>path</code> which will be parsed
 * and split into single elements. It will usually be used
 * to define a path from an environment variable.
 *
 * @author Hans Lellelid <hans@xmpl.org> (Phing)
 * @author Thomas.Haas@softwired-inc.com (Ant)
 * @author Stefan Bodewig <stefan.bodewig@epost.de> (Ant)
 * @package phing.types
 */
class Path extends DataType {

    private $elements = array();    
    
    /**
     * Constructor for internally instantiated objects sets project.
     * @param Project $project
     * @param string $path (for use by IntrospectionHelper)
     */
    public function __construct($project = null, $path = null) {
        if ($project !== null) {
            $this->setProject($project);
        }
        if ($path !== null) {
            $this->createPathElement()->setPath($path);
        }        
    }

    /**
     * Adds a element definition to the path.
     * @param $location the location of the element to add (must not be
     * <code>null</code> nor empty.
     * @throws BuildException
     */
    public function setDir(PhingFile $location) {
        if ($this->isReference()) {
            throw $this->tooManyAttributes();
        }        
        $this->createPathElement()->setDir($location);
    }

    /**
     * Parses a path definition and creates single PathElements.
     * @param path the path definition.
     * @throws BuildException
     */
    public function setPath($path) {
        if ($this->isReference()) {
            throw $this->tooManyAttributes();
        }
        $this->createPathElement()->setPath($path);
    }

    /**
     * Makes this instance in effect a reference to another Path instance.
     *
     * <p>You must not set another attribute or nest elements inside
     * this element if you make it a reference.</p>
     * @throws BuildException
     */
    public function setRefid(Reference $r)  {
        if (!empty($this->elements)) {
            throw $this->tooManyAttributes();
        }
        $this->elements[] = $r;
        parent::setRefid($r);
    }

    /**
     * Creates the nested <code>&lt;pathelement&gt;</code> element.
     * @throws BuildException 
     */
    public function createPathElement() {
        if ($this->isReference()) {
            throw $this->noChildrenAllowed();
        }
        $pe = new PathElement($this);
        $this->elements[] = $pe;
        return $pe;
    }

    /**
     * Adds a nested <code>&lt;fileset&gt;</code> element.
     * @throws BuildException 
     */
    public function addFileset(FileSet $fs) {
        if ($this->isReference()) {
            throw $this->noChildrenAllowed();
        }
        $this->elements[] = $fs;
        $this->checked = false;
    }

    /**
     * Adds a nested <code>&lt;dirset&gt;</code> element.
     * @throws BuildException 
     */
    public function addDirset(DirSet $dset) {
        if ($this->isReference()) {
            throw $this->noChildrenAllowed();
        }
        $this->elements[] = $dset;
        $this->checked = false;
    }

    /**
     * Creates a nested <code>&lt;path&gt;</code> element.
     * @throws BuildException
     */
    public function createPath() {
        if ($this->isReference()) {
            throw $this->noChildrenAllowed();
        }
        $p = new Path($this->project);
        $this->elements[] = $p;
        $this->checked = false;
        return $p;
    }

    /**
     * Append the contents of the other Path instance to this.
     */
    public function append(Path $other) {
        if ($other === null) {
            return;
        }
        $l = $other->listPaths();
        foreach($l as $path) {
            if (!in_array($path, $this->elements, true)) {
                $this->elements[] = $path;
            }
        }
    }

     /**
     * Adds the components on the given path which exist to this
     * Path. Components that don't exist, aren't added.
     *
     * @param Path $source - Source path whose components are examined for existence.
     */
    public function addExisting(Path $source) {
        $list = $source->listPaths();
        foreach($list as $el) {
            $f = null;
            if ($this->project !== null) {
                $f = $this->project->resolveFile($el);
            } else {
                $f = new PhingFile($el);
            }

            if ($f->exists()) {
                $this->setDir($f);
            } else {
                $this->log("dropping " . $f->__toString() . " from path as it doesn't exist", 
                    Project::MSG_VERBOSE);
            }
        }
    }

    /**
     * Returns all path elements defined by this and nested path objects.
     * @return array List of path elements.
     */
    public function listPaths() {
        if (!$this->checked) {
            // make sure we don't have a circular reference here
            $stk = array();
            array_push($stk, $this);
            $this->dieOnCircularReference($stk, $this->project);
        }

        $result = array();
        for ($i = 0, $elSize=count($this->elements); $i < $elSize; $i++) {
            $o = $this->elements[$i];
            if ($o instanceof Reference) {
                $o = $o->getReferencedObject($this->project);
                // we only support references to paths right now
                if (!($o instanceof Path)) {
                    $msg = $r->getRefId() . " doesn't denote a path";
                    throw new BuildException($msg);
                }
            }
            
            if (is_string($o)) {
                $result[] = $o;
            } elseif ($o instanceof PathElement) {
                $parts = $o->getParts();
                if ($parts === null) {
                    throw new BuildException("You must either set location or" 
                        . " path on <pathelement>");
                }
                foreach($parts as $part) {
                    $result[] = $part;
                }
            } elseif ($o instanceof Path) {
                $p = $o;
                if ($p->getProject() === null) {
                    $p->setProject($this->getProject());
                }
                $parts = $p->listPaths();
                foreach($parts as $part) {
                    $result[] = $part;
                }
            } elseif ($o instanceof DirSet) {
                $dset = $o;
                $ds = $dset->getDirectoryScanner($this->project);
                $dirstrs = $ds->getIncludedDirectories();
                $dir = $dset->getDir($this->project);
                foreach($dirstrs as $dstr) {
                    $d = new PhingFile($dir, $dstr);
                    $result[] = $d->getAbsolutePath();
                }
                var_dump($result);
            } elseif ($o instanceof FileList) {
                $fl = $o;
                $dirstrs = $fl->getFiles($this->project);
                $dir = $fl->getDir($this->project);
                foreach($dirstrs as $dstr) {
                    $d = new PhingFile($dir, $dstr);
                    $result[] = $d->getAbsolutePath();
                }
            }
        }
        
        return array_unique($result);
    }


    /**
     * Returns a textual representation of the path, which can be used as
     * CLASSPATH or PATH environment variable definition.
     * @return string A textual representation of the path.
     */
    public function __toString() {
        
        $list = $this->listPaths();

        // empty path return empty string
        if (empty($list)) {
            return "";
        }
        
        return implode(PATH_SEPARATOR, $list);
    }

    /**
     * Splits a PATH (with : or ; as separators) into its parts.
     * @param Project $project
     * @param string $source
     */
    public static function translatePath(Project $project, $source) {
        $result = array();
        if ($source == null) {
          return "";
        }

        $tok = new PathTokenizer($source);
        while ($tok->hasMoreTokens()) {
            $pathElement = $tok->nextToken();
            try {
                $element = self::resolveFile($project, $pathElement);
                for ($i = 0, $_i=strlen($element); $i < $_i; $i++) {
                    self::translateFileSep($element, $i);
                }
                $result[] = $element;
            } catch (BuildException $e) {
                $this->project->log("Dropping path element " . $pathElement
                    . " as it is not valid relative to the project",
                    Project::MSG_VERBOSE);
            }
        }
        
        return $result;
    }

    /**
     * Returns its argument with all file separator characters
     * replaced so that they match the local OS conventions.  
     */
    public static function translateFile($source) {
        if ($source == null) {
          return "";
        }

        $result = $source;
        for ($i = 0, $_i=strlen($source); $i < $_i; $i++) {
            self::translateFileSep($result, $i);
        }
        
        return $result;
    }

    /**
     * Translates all occurrences of / or \ to correct separator of the
     * current platform and returns whether it had to do any
     * replacements.  
     */
    protected static function translateFileSep(&$buffer, $pos) {
        if ($buffer{$pos} == '/' || $buffer{$pos} == '\\') {
            $buffer{$pos} = DIRECTORY_SEPARATOR;
            return true;
        }
        return false;
    }

    /**
     * How many parts does this Path instance consist of.
     * DEV NOTE: expensive call! list is generated, counted, and then
     * discareded.
     * @return int
     */
    public function size() {
        return count($this->listPaths());
    }

    /**
     * Return a Path that holds the same elements as this instance.
     */
    public function __clone() {
        $p = new Path($this->project);
        $p->append($this);
        return $p;
    }

    /**
     * Overrides the version of DataType to recurse on all DataType
     * child elements that may have been added.  
     * @throws BuildException
     */
    public function dieOnCircularReference(&$stk, Project $p) {

        if ($this->checked) {
            return;
        }
    
        // elements can contain strings, FileSets, Reference, etc.
        foreach($this->elements as $o) {
            
            if ($o instanceof Reference) {
                $o = $o->getReferencedObject($p);
            }

            if ($o instanceof DataType) {
                if (in_array($o, $stk, true)) {
                    throw $this->circularReference();
                } else {
                    array_push($stk, $o);
                    $o->dieOnCircularReference($stk, $p);
                    array_pop($stk);
                }
            }
        }
        
        $this->checked = true;
    }

    /**
     * Resolve a filename with Project's help - if we know one that is.
     *
     * <p>Assume the filename is absolute if project is null.</p>
     */
    private static function resolveFile(Project $project, $relativeName) {
        if ($project !== null) {
            $f = $project->resolveFile($relativeName);
            return $f->getAbsolutePath();
        }
        return $relativeName;
    }
    
}


/**
 * Helper class, holds the nested <code>&lt;pathelement&gt;</code> values.
 */
class PathElement {

    private $parts = array();
    private $outer;
    
    public function __construct(Path $outer) {
        $this->outer = $outer;
    }
    
    public function setDir(PhingFile $loc) {
        $this->parts = array(Path::translateFile($loc->getAbsolutePath()));
    }

    public function setPath($path) {
        $this->parts = Path::translatePath($this->outer->getProject(), $path);
    }

    public function getParts() {
        return $this->parts;
    }
}
