<?php
/**
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2002-2008 (original work) Public Research Centre Henri Tudor & University of Luxembourg (under the project TAO & TAO2);
 *               2008-2010 (update and modification) Deutsche Institut für Internationale Pädagogische Forschung (under the project TAO-TRANSFER);
 *               2009-2012 (update and modification) Public Research Centre Henri Tudor (under the project TAO-SUSTAIN & TAO-DEV);
 *
 */

/**
 * Short description of class common_configuration_ComponentCollection
 *
 * @access public
 * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
 * @package generis

 */
class common_configuration_ComponentCollection
{
    // --- ASSOCIATIONS ---


    // --- ATTRIBUTES ---

    /**
     * The components that have to be checked.
     *
     * @access private
     * @var array
     */
    private $components = [];

    /**
     * An array of arrays. The arrays contained in this field are associative
     * with the following keys: 'component' is the component on which other
     * have dependencies. 'depends' is an array containing components that have
     * dependency on 'component'.
     *
     * @access private
     * @var array
     */
    private $dependencies = [];

    /**
     * Short description of attribute checkedComponents
     *
     * @access private
     * @var array
     */
    private $checkedComponents = [];

    /**
     * Short description of attribute reports
     *
     * @access public
     * @var array
     */
    public $reports = [];

    /**
     * Short description of attribute silentComponents
     *
     * @access private
     * @var array
     */
    private $silentComponents = [];

    /**
     * Short description of attribute rootComponent
     *
     * @access private
     * @var Component
     */
    private $rootComponent = null;

    // --- OPERATIONS ---

    /**
     * Short description of method addComponent
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return void
     */
    public function addComponent(common_configuration_Component $component)
    {
        
        $components = $this->getComponents();
        
        // Search for a similar...
        foreach ($components as $c) {
            if ($c === $component) {
                // Already stored.
                return;
            }
        }
        
        // Not stored yet.
        $components[] = $component;
        $this->setComponents($components);
    }

    /**
     * Short description of method addDependency
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @param  Component dependency
     * @return void
     */
    public function addDependency(common_configuration_Component $component, common_configuration_Component $dependency)
    {
        
        $dependencies = $this->getDependencies();
        
        $found = false;
        foreach ($dependencies as $dep) {
            if ($dependency === $dep['component'] && $component === $dep['isDependencyOf']) {
                $found = true;
                break;
            }
        }
        
        if (false == $found) {
            $dependencies[] = ['component' => $dependency, 'isDependencyOf' => $component];
            $this->setDependencies($dependencies);
        }
    }

    /**
     * Short description of method reset
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return void
     */
    public function reset()
    {
        
        $this->setComponents([]);
        $this->setDependencies([]);
        $this->setCheckedComponents([]);
        $this->setSilentComponents([]);
    }

    /**
     * Returns an array of Reports.
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function check()
    {
        $returnValue = [];

        
        // Reset what should be reset for another check on the same instance.
        $this->setCheckedComponents([]);
        $this->setReports([]);
        
        $components = $this->getComponents();
        $dependencies = $this->getDependencies();
        $traversed = [];
        
        // Any node that has no incoming edge and is not
        // the root mock should be bound to it.
        foreach ($components as $c) {
            $found = false;
            foreach ($this->getDependencies() as $d) {
                if ($c === $d['isDependencyOf']) {
                    // Incoming edge(s).
                    $found = true;
                    break;
                }
            }
            
            // No incoming edge.
            if ($found === false && $c !== $this->getRootComponent()) {
                $this->addDependency($c, $this->getRootComponent());
            }
        }
        
        if (count($components) > 0) {
            if (true == $this->isAcyclic()) {
                // We go for a Depth First Search in the graph.
                $stack = [];
                $node = $components[0];
                
                // Do something with my node.
                $status = $this->checkComponent($node);
                array_push($traversed, $node); // mark the node as 'traversed'.
                
                if ($status == common_configuration_Report::VALID) {
                    $stack = self::pushTransitionsOnStack($stack, $this->getTransitions($node)); // put all transitions from the node to stack.
                    
                    while (count($stack) > 0) {
                        $transition = array_pop($stack);
                        $node = $transition['isDependencyOf'];
                        
                        // If not already traversed, do something with my node.
                        if (false == in_array($node, $traversed)) {
                            // Do something with my node.
                            $status = $this->checkComponent($node);
                            array_push($traversed, $node);
                            
                            if ($status == common_configuration_Report::VALID) {
                                $stack = self::pushTransitionsOnStack($stack, $this->getTransitions($node));
                            }
                        }
                    }
                }
                
                $returnValue = $this->getReports();
            } else {
                throw new common_configuration_CyclicDependencyException("The dependency graph is cyclic. Please review your dependencies.");
            }
        }
        
        
        return (array) $returnValue;
    }

    /**
     * Short description of method isAcyclic
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return boolean
     */
    private function isAcyclic()
    {
        $returnValue = (bool) false;

        
        // To detect if the dependency graph is acyclic or not,
        // we first perform a usual Topological Sorting algorithm.
        // If at the end of the algorith, we still have edges,
        // the graph is cyclic !
        
        
        $l = []; // Empty list where elements are sorted.
        $q = []; // Set of nodes with no incoming edges.
        
        $components = $this->getComponents();
        $dependencies = $this->getDependencies(); // used as a copy !
        
        // Set q with nodes with no incoming edges.
        foreach ($components as $c) {
            $incomingEdges = false;
            
            foreach ($dependencies as $d) {
                if ($c === $d['isDependencyOf']) {
                    // $c has incoming edges thus we reject it.
                    $incomingEdges = true;
                    break;
                }
            }
            
            if ($incomingEdges == false) {
                array_push($q, $c);
            }
        }
        
        while (count($q) > 0) {
            $n = array_pop($q);
            array_push($l, $n);
            
            foreach ($components as $m) {
                // edge from n to m ?
                foreach ($dependencies as $k => $dep) {
                    if ($dep['component'] === $n && $dep['isDependencyOf'] === $m) {
                        unset($dependencies[$k]);
                        
                        // other incoming edges for m ?
                        foreach ($dependencies as $dep) {
                            if ($dep['isDependencyOf'] === $m) {
                                break 2;
                            }
                        }
                        
                        // no incoming edges from m !
                        array_push($q, $m);
                    }
                }
            }
        }
        
        $returnValue = count($dependencies) == 0;
        

        return (bool) $returnValue;
    }

    /**
     * Short description of method getTransitions
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return array
     */
    private function getTransitions(common_configuration_Component $component)
    {
        $returnValue = [];

        
        $dependencies = $this->dependencies;
        foreach ($dependencies as $d) {
            if ($d['component'] === $component) {
                array_push($returnValue, $d);
            }
        }
        

        return (array) $returnValue;
    }

    /**
     * Short description of method getCheckedComponents
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function getCheckedComponents()
    {
        $returnValue = [];

        
        // Sort the checked components to make them ordered in the same
        // way the related components where added.
        $components = $this->getComponents();
        $checkedComponents = [];
        foreach ($components as $c) {
            foreach ($this->checkedComponents as $cC) {
                if ($cC === $c) {
                    array_push($checkedComponents, $cC);
                }
            }
        }
        
        
        $returnValue = $checkedComponents;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method getUncheckedComponents
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function getUncheckedComponents()
    {
        $returnValue = [];

        
        $rootMock = $this->getRootComponent();
        foreach ($this->getComponents() as $c) {
            if (false === in_array($c, $this->getCheckedComponents()) && $c !== $rootMock) {
                array_push($returnValue, $c);
            }
        }
        
        // Sort the checked components to make them ordered in the same
        // way the related components where added.
        $components = $this->getComponents();
        $uncheckedComponents = [];
        foreach ($components as $c) {
            foreach ($returnValue as $uC) {
                if ($uC === $c) {
                    array_push($uncheckedComponents, $uC);
                }
            }
        }
        
        $returnValue = $uncheckedComponents;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method pushTransitionsOnStack
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array stack
     * @param  array transitions
     * @return array
     */
    public static function pushTransitionsOnStack($stack, $transitions)
    {
        $returnValue = [];

        
        foreach ($transitions as $t) {
            array_push($stack, $t);
        }
        
        $returnValue = $stack;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method setComponents
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array components
     * @return void
     */
    public function setComponents($components)
    {
        
        $this->components = $components;
    }

    /**
     * Short description of method getComponents
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function getComponents()
    {
        $returnValue = [];

        
        $returnValue = $this->components;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method setCheckedComponents
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array checkedComponents
     * @return void
     */
    private function setCheckedComponents($checkedComponents)
    {
        
        $this->checkedComponents = $checkedComponents;
    }

    /**
     * Short description of method setDependencies
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array dependencies
     * @return void
     */
    private function setDependencies($dependencies)
    {
        
        $this->dependencies = $dependencies;
    }

    /**
     * Short description of method getDependencies
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    private function getDependencies()
    {
        $returnValue = [];

        
        $returnValue = $this->dependencies;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method setReports
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array reports
     * @return mixed
     */
    private function setReports($reports)
    {
        
        $this->reports = $reports;
    }

    /**
     * Short description of method getReports
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function getReports()
    {
        $returnValue = [];

        
        if (count($this->reports) == 0) {
            return $returnValue;
        } else {
            // Sort the reports to make them ordered in the same
            // order the related components where added.
            $components = $this->getComponents();
            $reports = [];
            foreach ($components as $c) {
                foreach ($this->reports as $r) {
                    if ($r->getComponent() === $c) {
                        array_push($reports, $r);
                    }
                }
            }
        }
        
        $returnValue = $reports;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method addReport
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Report report
     * @return void
     */
    private function addReport(common_configuration_Report $report)
    {
        
        array_push($this->reports, $report);
    }

    /**
     * Short description of method componentChecked
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return void
     */
    private function componentChecked(common_configuration_Component $component)
    {
        
        if ($component !== $this->getRootComponent()) {
            array_push($this->checkedComponents, $component);
        }
    }

    /**
     * Short description of method checkComponent
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return int
     */
    private function checkComponent(common_configuration_Component $component)
    {
        $returnValue = (int) 0;

        
        $report = $component->check(); // Check the node.
        $this->componentChecked($component); // Mark the node as 'checked'.
        
        // Store the report if not silenced.
        if (false == $this->isSilent($component)) {
            $this->addReport($report); // Store the report.
        }
        
        $returnValue = $report->getStatus();
        

        return (int) $returnValue;
    }

    /**
     * Short description of method getSilentComponents
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return array
     */
    public function getSilentComponents()
    {
        $returnValue = [];

        
        $returnValue = $this->silentComponents;
        

        return (array) $returnValue;
    }

    /**
     * Short description of method setSilentComponents
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  array silentComponents
     * @return void
     */
    private function setSilentComponents($silentComponents)
    {
        
        $this->silentComponents = $silentComponents;
    }

    /**
     * Short description of method silent
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return void
     */
    public function silent(common_configuration_Component $component)
    {
        
        $silentComponents = $this->getSilentComponents();
        foreach ($silentComponents as $silent) {
            if ($silent === $component) {
                return;
            }
        }
        
        $silentComponents[] = $component;
        $this->setSilentComponents($silentComponents);
    }

    /**
     * Short description of method noisy
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return void
     */
    public function noisy(common_configuration_Component $component)
    {
        
        $silentComponents = $this->getSilentComponents();
        
        foreach ($silentComponents as $k => $silent) {
            if ($silent === $component) {
                unset($silentComponents[$k]);
            }
        }
        
        $this->setSilentComponents($silentComponents);
    }

    /**
     * Short description of method isSilent
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return boolean
     */
    private function isSilent(common_configuration_Component $component)
    {
        $returnValue = (bool) false;

        
        $returnValue = in_array($component, $this->getSilentComponents());
        

        return (bool) $returnValue;
    }

    /**
     * Short description of method isNoisy
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return boolean
     */
    private function isNoisy(common_configuration_Component $component)
    {
        $returnValue = (bool) false;

        
        $returnValue = !in_array($component, $this->getSilentComponents());
        

        return (bool) $returnValue;
    }

    /**
     * Short description of method __construct
     *
     * @access public
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return mixed
     */
    public function __construct()
    {
        
        
        // A mock root check on which any added component has a dependence. The goal
        // of this is to make sure that components will not stay alone with no
        // incoming edges in the dependency graph, making them unreachable.
        $rootStatus = common_configuration_Report::VALID;
        $root = new common_configuration_Mock($rootStatus, 'tao.dependencies.root');
        $this->setRootComponent($root);
    }

    /**
     * Short description of method setRootComponent
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @param  Component component
     * @return void
     */
    private function setRootComponent(common_configuration_Component $component)
    {
        
        $this->rootComponent = $component;
        $components = $this->getComponents();
        $components[] = $component;
        $this->setComponents($components);
        $this->silent($component);
    }

    /**
     * Short description of method getRootComponent
     *
     * @access private
     * @author Jerome Bogaerts, <jerome.bogaerts@tudor.lu>
     * @return common_configuration_Component
     */
    private function getRootComponent()
    {
        $returnValue = null;

        
        $returnValue = $this->rootComponent;
        

        return $returnValue;
    }
}