<?php

/*
 *  $Id: IntrospectionHelper.php 930 2010-10-13 19:03:28Z victor $
 *
 * 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/types/Reference.php';
include_once 'phing/types/Path.php';
include_once 'phing/util/StringHelper.php';

/**
 * Helper class that collects the methods that a task or nested element
 * holds to set attributes, create nested elements or hold PCDATA
 * elements.
 *
 *<ul>
 * <li><strong>SMART-UP INLINE DOCS</strong></li>
 * <li><strong>POLISH-UP THIS CLASS</strong></li>
 *</ul>
 *
 * @author    Andreas Aderhold <andi@binarycloud.com>
 * @author    Hans Lellelid <hans@xmpl.org>
 * @copyright 2001,2002 THYRELL. All rights reserved
 * @version   $Revision: 930 $
 * @package   phing
 */
class IntrospectionHelper {



    /** 
     * Holds the attribute setter methods.
     * 
     * @var array string[]
     */
    private $attributeSetters = array();

    /**  
     * Holds methods to create nested elements. 
     *
     * @var array string[]
     */
    private $nestedCreators = array();

    /**
     * Holds methods to store configured nested elements. 
     *
     * @var array string[]
     */
    private $nestedStorers = array();
    
    /**
     * Map from attribute names to nested types.
     */
    private $nestedTypes = array();
        
    /**
     * New idea in phing: any class can register certain
     * keys -- e.g. "task.current_file" -- which can be used in
     * task attributes, if supported.  In the build XML these
     * are referred to like this:
     *         <regexp pattern="\n" replace="%{task.current_file}"/>
     * In the type/task a listener method must be defined:
     *         function setListeningReplace($slot) {}
     * @var array string[]
      */
    private $slotListeners = array();
    
    /** 
     * The method to add PCDATA stuff. 
     *
     * @var string Method name of the addText (redundant?) method, if class supports it :)
     */
    private $methodAddText = null;

    /**
     * The Class that's been introspected.
     *
     * @var     object
     * @access  private
     */
    private $bean;
    
    /**
     * The cache of IntrospectionHelper classes instantiated by getHelper().
     * @var array IntrospectionHelpers[]
     */
    private static $helpers = array();
    
    /** 
     * Factory method for helper objects. 
     *
     * @param string $class The class to create a Helper for
     */
    public static function getHelper($class) {
        if (!isset(self::$helpers[$class])) {
            self::$helpers[$class] = new IntrospectionHelper($class);
        }
        return self::$helpers[$class];
    }

    /**
     * This function constructs a new introspection helper for a specific class.
     * 
     * This method loads all methods for the specified class and categorizes them
     * as setters, creators, slot listeners, etc.  This way, the setAttribue() doesn't
     * need to perform any introspection -- either the requested attribute setter/creator
     * exists or it does not & a BuildException is thrown.
     * 
     * @param string $bean The classname for this IH.
     */
    function __construct($class) {
    
        $this->bean = new ReflectionClass($class);
        
        //$methods = get_class_methods($bean);
        foreach($this->bean->getMethods() as $method) {
        
            if ($method->isPublic()) {                
            
                // We're going to keep case-insensitive method names
                // for as long as we're allowed :)  It makes it much
                // easier to map XML attributes to PHP class method names.
                $name = strtolower($method->getName());
                
                // There are a few "reserved" names that might look like attribute setters
                // but should actually just be skipped.  (Note: this means you can't ever
                // have an attribute named "location" or "tasktype" or a nested element named "task".)
                if ($name === "setlocation" || $name === "settasktype" || $name === "addtask") {
                    continue;
                }
                
                if ($name === "addtext") {
                    
                    $this->methodAddText = $method;
                    
                } elseif (strpos($name, "setlistening") === 0) {
                    
                    // Phing supports something unique called "RegisterSlots"
                    // These are dynamic values that use a basic slot system so that
                    // classes can register to listen to specific slots, and the value
                    // will always be grabbed from the slot (and never set in the project
                    // component).  This is useful for things like tracking the current
                    // file being processed by a filter (e.g. AppendTask sets an append.current_file
                    // slot, which can be ready by the XSLTParam type.)
                    
                    if (count($method->getParameters()) !== 1) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() must take exactly one parameter.");
                    }
                                                
                    $this->slotListeners[$name] = $method;
                    
                } elseif (strpos($name, "set") === 0) {
                    
                    // A standard attribute setter.
                    
                    if (count($method->getParameters()) !== 1) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() must take exactly one parameter.");
                    }
                    
                    $this->attributeSetters[$name] = $method;
                    
                } elseif (strpos($name, "create") === 0) {                            
                    
                    if ($method->getNumberOfRequiredParameters() > 0) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() may not take any parameters.");
                    }
                    
                    // Because PHP doesn't support return types, we are going to do
                    // two things here to guess return type:
                    //     1) parse comments for an explicit value
                    //     2) if that fails, assume that the part of the method after "create"
                    //    is the name of the return type (in many cases it is not)
                    
                    // This isn't super important -- i.e. we're not instantaiting classes
                    // based on this information.  It's more just so that IntrospectionHelper
                    // can keep track of all the nested types -- and provide more helpful
                    // exception messages, etc.
                                
                    preg_match('/@return[\s]+([\w]+)/', $method->getDocComment(), $matches);
                    if (!empty($matches[1]) && class_exists($matches[1], false)) {
                        $this->nestedTypes[$name] = $matches[1];
                    } else {                    
                        // assume that method createEquals() creates object of type "Equals"
                        // (that example would be false, of course)                    
                        $this->nestedTypes[$name] = $this->getPropertyName($name, "create");
                    }
                    
                    $this->nestedCreators[$name] = $method;
                    
                } elseif (strpos($name, "addconfigured") === 0) {
                    
                    // *must* use class hints if using addConfigured ...
                    
                    // 1 param only
                    $params = $method->getParameters();
                    
                    if (count($params) < 1) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() must take at least one parameter.");
                    }
                    
                    if (count($params) > 1) {
                        $this->warn($method->getDeclaringClass()->getName()."::".$method->getName()."() takes more than one parameter. (IH only uses the first)");
                    }
                    
                    $classname = null;
                    
                    if (($hint = $params[0]->getClass()) !== null) { 
                        $classname = $hint->getName();    
                    }                    
                    
                    if ($classname === null) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() method MUST use a class hint to indicate the class type of parameter.");
                    }
                        
                    $this->nestedTypes[$name] = $classname;
                
                    $this->nestedStorers[$name] = $method;
                    
                } elseif (strpos($name, "add") === 0) {
                    
                    // *must* use class hints if using add ...
                    
                    // 1 param only
                    $params = $method->getParameters();
                    if (count($params) < 1) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() must take at least one parameter.");
                    }
                    
                    if (count($params) > 1) {
                        $this->warn($method->getDeclaringClass()->getName()."::".$method->getName()."() takes more than one parameter. (IH only uses the first)");
                    }

                    $classname = null;
                    
                    if (($hint = $params[0]->getClass()) !== null) { 
                        $classname = $hint->getName();    
                    }                    
                    
                    // we don't use the classname here, but we need to make sure it exists before
                    // we later try to instantiate a non-existant class
                    if ($classname === null) {
                        throw new BuildException($method->getDeclaringClass()->getName()."::".$method->getName()."() method MUST use a class hint to indicate the class type of parameter.");
                    }
                
                    $this->nestedCreators[$name] = $method;
                } 
            } // if $method->isPublic()        
        } // foreach        
    }


    /** Sets the named attribute. */
    function setAttribute(Project $project, $element, $attributeName, &$value) {
        
        // we want to check whether the value we are setting looks like
        // a slot-listener variable:  %{task.current_file}
        //
        // slot-listener variables are not like properties, in that they cannot be mixed with
        // other text values.  The reason for this disparity is that properties are only
        // set when first constructing objects from XML, whereas slot-listeners are always dynamic.
        //
        // This is made possible by PHP5 (objects automatically passed by reference) and PHP's loose
        // typing.
        
        if (StringHelper::isSlotVar($value)) {
            
            $as = "setlistening" . strtolower($attributeName);

            if (!isset($this->slotListeners[$as])) {
                $msg = $this->getElementName($project, $element) . " doesn't support a slot-listening '$attributeName' attribute.";
                throw new BuildException($msg);
            }
            
            $method = $this->slotListeners[$as];
            
            $key = StringHelper::slotVar($value);
            $value = Register::getSlot($key); // returns a RegisterSlot object which will hold current value of that register (accessible using getValue())
            
        } else {
            
            // Traditional value options
            
            $as = "set".strtolower($attributeName);
            
            if (!isset($this->attributeSetters[$as])) {
                $msg = $this->getElementName($project, $element) . " doesn't support the '$attributeName' attribute.";
                throw new BuildException($msg);
            }
            
            $method = $this->attributeSetters[$as];            
            
            if ($as == "setrefid") {            
                $value = new Reference($value);
            } else {
                // value is a string representation of a boolean type,
                // convert it to primitive
                if (StringHelper::isBoolean($value)) {

                    $value = StringHelper::booleanValue($value);
                }
                
                // does method expect a PhingFile object? if so, then 
                // pass a project-relative file.
                $params = $method->getParameters();

                $classname = null;
                
                if (($hint = $params[0]->getClass()) !== null) { 
                    $classname = $hint->getName();    
                }
                
                // there should only be one param; we'll just assume ....
                if ($classname !== null) {
                    switch(strtolower($classname)) {
                        case "phingfile":
                            $value = $project->resolveFile($value);
                            break;
                        case "path":
                            $value = new Path($project, $value);
                            break;
                        case "reference":
                            $value = new Reference($value);
                            break;            
                        // any other object params we want to support should go here ...
                    }
                    
                } // if hint !== null
                
            } // if not setrefid
            
        } // if is slot-listener
        
        try {
            $project->log("    -calling setter ".$method->getDeclaringClass()->getName()."::".$method->getName()."()", Project::MSG_DEBUG);
            $method->invoke($element, $value);
        } catch(Exception $exc) {
            throw new BuildException($exc);
        }
        
    }

    /** Adds PCDATA areas.*/
    function addText(Project $project, $element, $text) {
        if ($this->methodAddText === null) {
            $msg = $this->getElementName($project, $element)." doesn't support nested text data.";
            throw new BuildException($msg);
        }        
        try {
            $method = $this->methodAddText;
            $method->invoke($element, $text);
        } catch (Exception $exc) {
            throw new BuildException($exc);
        }
    }

    /**
     * Creates a named nested element. 
     * 
     * Valid creators can be in the form createFoo() or addFoo(Bar).
     * @return object Returns the nested element.
     * @throws BuildException
     */
    function createElement(Project $project, $element, $elementName) {
    
        $addMethod = "add".strtolower($elementName);
        $createMethod = "create".strtolower($elementName);
        $nestedElement = null;
        
        if (isset($this->nestedCreators[$createMethod])) {
            
            $method = $this->nestedCreators[$createMethod];
             try { // try to invoke the creator method on object
                $project->log("    -calling creator ".$method->getDeclaringClass()->getName()."::".$method->getName()."()", Project::MSG_DEBUG);
                $nestedElement = $method->invoke($element);
            } catch (Exception $exc) {
                throw new BuildException($exc);
            }            
            
        } elseif (isset($this->nestedCreators[$addMethod])) {            
            
            $method = $this->nestedCreators[$addMethod];
            
            // project components must use class hints to support the add methods
            
            try { // try to invoke the adder method on object
            
                $project->log("    -calling adder ".$method->getDeclaringClass()->getName()."::".$method->getName()."()", Project::MSG_DEBUG);
                // we've already assured that correct num of params
                // exist and that method is using class hints                
                $params = $method->getParameters();

                $classname = null;
            
                if (($hint = $params[0]->getClass()) !== null) { 
                    $classname = $hint->getName();    
                }                
                
                // create a new instance of the object and add it via $addMethod                
                $nestedElement = new $classname();
                
                $method->invoke($element, $nestedElement);
                                
            } catch (Exception $exc) {
                throw new BuildException($exc);
            }
        } else {
            $msg = $this->getElementName($project, $element) . " doesn't support the '$elementName' creator/adder.";
            throw new BuildException($msg);
        }                                
        
        if ($nestedElement instanceof ProjectComponent) {
            $nestedElement->setProject($project);
        }
        
        return $nestedElement;
    }

    /**
     * Creates a named nested element.
     * @return void
     * @throws BuildException
     */
    function storeElement($project, $element, $child, $elementName = null) {
    
        if ($elementName === null) {
            return;
        }
        
        $storer = "addconfigured".strtolower($elementName);
          
        if (isset($this->nestedStorers[$storer])) {
            
            $method = $this->nestedStorers[$storer];
            
            try {                                
                $project->log("    -calling storer ".$method->getDeclaringClass()->getName()."::".$method->getName()."()", Project::MSG_DEBUG);                    
                $method->invoke($element, $child);            
            } catch (Exception $exc) {
                throw new BuildException($exc);
            }
        }
        
    }

    /** Does the introspected class support PCDATA? */
    function supportsCharacters() {
        return ($this->methodAddText !== null);
    }

    /** Return all attribues supported by the introspected class. */
    function getAttributes() {
        $attribs = array();
        foreach (array_keys($this->attributeSetters) as $setter) {
            $attribs[] =$this->getPropertyName($setter, "set");
        }
        return $attribs;
    }

    /** Return all nested elements supported by the introspected class. */
    function getNestedElements() {
        return $this->nestedTypes;
    }
    
    /**
     * Get the the name for an element.
     * When possible the full classnam (phing.tasks.system.PropertyTask) will
     * be returned.  If not available (loaded in taskdefs or typedefs) then the
     * XML element name will be returned.
     *
     * @param Project $project
     * @param object $element The Task or type element.
     * @return string Fully qualified class name of element when possible.
     */
    function getElementName(Project $project, $element) {
       
          $taskdefs = $project->getTaskDefinitions();
        $typedefs = $project->getDataTypeDefinitions();
        
        // check if class of element is registered with project (tasks & types)        
        // most element types don't have a getTag() method
        $elClass = get_class($element);
        
        if (!in_array('getTag', get_class_methods($elClass))) {
                // loop through taskdefs and typesdefs and see if the class name
                // matches (case-insensitive) any of the classes in there
                foreach(array_merge($taskdefs, $typedefs) as $elName => $class) {
                    if (0 === strcasecmp($elClass, StringHelper::unqualify($class))) {
                        return $class;
                    }
                }
                return "$elClass (unknown)";
        } else {
            // ->getTag() method does exist, so use it
            $elName = $element->getTag();
            if (isset($taskdefs[$elName])) {
                return $taskdefs[$elName];
            } elseif (isset($typedefs[$elName])) {

                return $typedefs[$elName];
            } else {
                return "$elName (unknown)";
            }
        }        
    }

    /** extract the name of a property from a method name - subtracting  a given prefix. */
    function getPropertyName($methodName, $prefix) {
        $start = strlen($prefix);
        return strtolower(substr($methodName, $start));
    }
    
    /**
     * Prints warning message to screen if -debug was used.
     */
    function warn($msg) {
        if (Phing::getMsgOutputLevel() === Project::MSG_DEBUG) {
            print("[IntrospectionHelper] " . $msg . "\n");
        }
    }

}
