<?php
// {{{ICINGA_LICENSE_HEADER}}}
// {{{ICINGA_LICENSE_HEADER}}}

use \Exception;
use Icinga\Config\PreservingIniWriter;
use Icinga\Web\Controller\ModuleActionController;
use Icinga\Web\Notification;
use Icinga\Module\Monitoring\Form\Config\ConfirmRemovalForm;
use Icinga\Module\Monitoring\Form\Config\Backend\EditBackendForm;
use Icinga\Module\Monitoring\Form\Config\Backend\CreateBackendForm;
use Icinga\Module\Monitoring\Form\Config\Instance\EditInstanceForm;
use Icinga\Module\Monitoring\Form\Config\Instance\CreateInstanceForm;
use Icinga\Exception\NotReadableError;

/**
 * Configuration controller for editing monitoring resources
 */
class Monitoring_ConfigController extends ModuleActionController
{
    /**
     * Display a list of available backends and instances
     */
    public function indexAction()
    {
        $this->view->tabs = $this->Module()->getConfigTabs()->activate('backends');
        foreach (array('backends', 'instances') as $element) {
            try {
                $elementConfig = $this->Config($element);
                if ($elementConfig === null) {
                    $this->view->{$element} = array();
                } else {
                    $this->view->{$element} = $elementConfig->toArray();
                }
            } catch (NotReadableError $e) {
                $this->view->{$element} = $e;
            }
        }
    }

    /**
     * Display a form to modify the backend identified by the 'backend' parameter of the request
     */
    public function editbackendAction()
    {
        $backend = $this->getParam('backend');
        if (!$this->isExistingBackend($backend)) {
            $this->view->error = 'Unknown backend ' . $backend;
            return;
        }
        $backendForm = new EditBackendForm();
        $backendForm->setRequest($this->getRequest());
        $backendForm->setBackendConfiguration($this->Config('backends')->get($backend));

        if ($backendForm->isSubmittedAndValid()) {
            $newConfig = $backendForm->getConfig();
            $config = $this->Config('backends');
            $config->$backend = $newConfig;
            if ($this->writeConfiguration($config, 'backends')) {
                Notification::success('Backend ' . $backend . ' Modified.');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
                return;
            }
        }
        $this->view->name = $backend;
        $this->view->form = $backendForm;
    }

    /**
     * Display a form to create a new backend
     */
    public function createbackendAction()
    {
        $form = new CreateBackendForm();
        $form->setRequest($this->getRequest());
        if ($form->isSubmittedAndValid()) {
            $configArray  =  $this->Config('backends')->toArray();
            $configArray[$form->getBackendName()] = $form->getConfig();

            if ($this->writeConfiguration(new Zend_Config($configArray), 'backends')) {
                Notification::success('Backend Creation Succeeded');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
            }
            return;
        }
        $this->view->form = $form;
        $this->render('editbackend');
    }

    /**
     * Display a confirmation form to remove the backend identified by the 'backend' parameter
     */
    public function removebackendAction()
    {
        $backend = $this->getParam('backend');
        if (!$this->isExistingBackend($backend)) {
            $this->view->error = 'Unknown backend ' . $backend;
            return;
        }
        $form = new ConfirmRemovalForm();
        $form->setRequest($this->getRequest());
        $form->setRemoveTarget('backend', $backend);

        if ($form->isSubmittedAndValid()) {
            $configArray = $this->Config('backends')->toArray();
            unset($configArray[$backend]);

            if ($this->writeConfiguration(new Zend_Config($configArray), 'backends')) {
                Notification::success('Backend "' . $backend . '" Removed');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
            }
            return;
        }

        $this->view->form = $form;
        $this->view->name = $backend;
    }

    /**
     * Display a confirmation form to remove the instance identified by the 'instance' parameter
     */
    public function removeinstanceAction()
    {
        $instance = $this->getParam('instance');
        if (!$this->isExistingInstance($instance)) {
            $this->view->error = 'Unknown instance ' . $instance;
            return;
        }

        $form = new ConfirmRemovalForm();
        $form->setRequest($this->getRequest());
        $form->setRemoveTarget('instance', $instance);

        if ($form->isSubmittedAndValid()) {
            $configArray = $this->Config('instances')->toArray();
            unset($configArray[$instance]);

            if ($this->writeConfiguration(new Zend_Config($configArray), 'instances')) {
                Notification::success('Instance "' . $instance . '" Removed');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
            }
            return;
        }

        $this->view->form = $form;
        $this->view->name = $instance;
    }

    /**
     * Display a form to edit the instance identified by the 'instance' parameter of the request
     */
    public function editinstanceAction()
    {
        $instance = $this->getParam('instance');
        if (!$this->isExistingInstance($instance)) {
            $this->view->error = 'Unknown instance ' . htmlentities($instance);
            return;
        }
        $form = new EditInstanceForm();
        $form->setInstanceConfiguration($this->Config('instances')->get($instance));
        $form->setRequest($this->getRequest());
        if ($form->isSubmittedAndValid()) {
            $instanceConfig = $this->Config('instances')->toArray();
            $instanceConfig[$instance] = $form->getConfig();
            if ($this->writeConfiguration(new Zend_Config($instanceConfig), 'instances')) {
                Notification::success('Instance Modified');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
                return;
            }
        }
        $this->view->form = $form;
    }

    /**
     * Display a form to create a new instance
     */
    public function createinstanceAction()
    {
        $form = new CreateInstanceForm();
        $form->setRequest($this->getRequest());
        if ($form->isSubmittedAndValid()) {
            $instanceConfig = $this->Config('instances');
            if ($instanceConfig === null) {
                $instanceConfig = array();
            } else {
                $instanceConfig = $instanceConfig->toArray();
            }
            $instanceConfig[$form->getInstanceName()] = $form->getConfig()->toArray();
            if ($this->writeConfiguration(new Zend_Config($instanceConfig), 'instances')) {
                Notification::success('Instance Creation Succeeded');
                $this->redirectNow('monitoring/config');
            } else {
                $this->render('show-configuration');
            }
            return;
        }
        $this->view->form = $form;
        $this->render('editinstance');
    }

    /**
     * Write configuration to an ini file
     *
     * @param   Zend_Config     $config     The configuration to write
     * @param   string          $file       The config file to write to
     *
     * @return  bool                        Whether the configuration was written or not
     */
    protected function writeConfiguration($config, $file)
    {
        $target = $this->Config($file)->getConfigFile();
        $writer = new PreservingIniWriter(array('filename' => $target, 'config' => $config));

        try {
            $writer->write();
        } catch (Exception $exc) {
            $this->view->exceptionMessage = $exc->getMessage();
            $this->view->iniConfigurationString = $writer->render();
            $this->view->file = $target;
            return false;
        }

        return true;
    }

    /**
     * Return whether the given backend exists in the current configuration
     *
     * @param   string  $backend    The name of the backend to check
     *
     * @return  bool                Whether the backend exists or not
     */
    protected function isExistingBackend($backend)
    {
        $backendCfg = $this->Config('backends');
        return $backend && $backendCfg->get($backend);
    }

    /**
     * Return whether the given instance exists in the current configuration
     *
     * @param   string  $instance   The name of the instance to check
     *
     * @return  bool                Whether the instance exists or not
     */
    protected function isExistingInstance($instance)
    {
        $instanceCfg = $this->Config('instances');
        return $instanceCfg && $instanceCfg->get($instance);
    }
}