<?php
namespace Grav\Plugin;

use Grav\Common\Cache;
use Grav\Common\Config\Config;
use Grav\Common\Filesystem\Folder;
use Grav\Common\Grav;
use Grav\Common\Themes;
use Grav\Common\Uri;
use Grav\Common\Data;
use Grav\Common\Page;
use Grav\Common\User\User;

class AdminController
{
    /**
     * @var Grav
     */
    public $grav;

    /**
     * @var string
     */
    public $view;

    /**
     * @var string
     */
    public $task;

    /**
     * @var string
     */
    public $route;

    /**
     * @var array
     */
    public $post;

    /**
     * @var Admin
     */
    protected $admin;

    /**
     * @var string
     */
    protected $redirect;

    /**
     * @var int
     */
    protected $redirectCode;

    /**
     * @param Grav   $grav
     * @param string $view
     * @param string $task
     * @param string $route
     * @param array  $post
     */
    public function __construct(Grav $grav, $view, $task, $route, $post)
    {
        $this->grav = $grav;
        $this->view = $view;
        $this->task = $task ? $task : 'display';
        $this->post = $this->getPost($post);
        $this->route = $route;
        $this->admin = $this->grav['admin'];
    }

    /**
     * Performs a task.
     */
    public function execute()
    {
        $success = false;
        $method = 'task' . ucfirst($this->task);
        if (method_exists($this, $method)) {
            try {
                $success = call_user_func(array($this, $method));
            } catch (\RuntimeException $e) {
                $success = true;
                $this->admin->setMessage($e->getMessage());
            }

            // Grab redirect parameter.
            $redirect = isset($this->post['_redirect']) ? $this->post['_redirect'] : null;
            unset($this->post['_redirect']);

            // Redirect if requested.
            if ($redirect) {
                $this->setRedirect($redirect);
            }
        }
        return $success;
    }

    public function redirect()
    {
        if (!$this->redirect) {
            return;
        }

        $base = $this->admin->base;
        $path = trim(substr($this->redirect, 0, strlen($base)) == $base ? substr($this->redirect, strlen($base)) : $this->redirect, '/');

        $this->grav->redirect($base . '/' . preg_replace('|/+|', '/', $path), $this->redirectCode);
    }

    /**
     * Handle login.
     *
     * @return bool True if the action was performed.
     */
    protected function taskLogin()
    {
        if ($this->admin->authenticate($this->post)) {
            $this->admin->setMessage('You have been logged in.');
        } else {
            $this->admin->setMessage('Login failed.');
        }

        return true;
    }

    /**
     * Handle logout.
     *
     * @return bool True if the action was performed.
     */
    protected function taskLogout()
    {
        $this->admin->session()->invalidate()->start();
        $this->admin->setMessage('You have been logged out.');
        $this->setRedirect('/');

        return true;
    }

    protected function taskForgot()
    {
        $data = $this->post;

        $username = isset($data['username']) ? $data['username'] : '';
        $user = !empty($username) ? User::load($username) : null;

        if (!isset($this->grav['Email'])) {
            $this->admin->setMessage('Cannot reset password. This site is not configured to send emails.');
            $this->setRedirect('/');
            return true;
        }

        if (!$user || !$user->exists()) {
            $this->admin->setMessage('User with username \'' . $username . '\' does not exist.');
            $this->setRedirect('/forgot');
            return true;
        }

        if (empty($user->email)) {
            $this->admin->setMessage('Cannot reset password for \'' . $username . '\', no email address is set.');
            $this->setRedirect('/forgot');
            return true;
        }

        $token = md5(uniqid(mt_rand(), true));
        $expire = time() + 604800; // next week

        $user->reset = $token . '::' . $expire;
        $user->save();

        $author = $this->grav['config']->get('site.author.name', '');
        $fullname = $user->fullname ?: $username;
        $reset_link = rtrim($this->grav['uri']->rootUrl(true), '/') . '/' . trim($this->admin->base, '/') . '/reset/task:reset/user:' . $username . '/token:' . $token;

        $from = $this->grav['config']->get('site.author.email', 'noreply@getgrav.org');
        $to = $user->email;
        $subject = $this->grav['config']->get('site.title', 'Website') . ' password reset';
        $body = $this->grav['twig']->processString('{% include "email/reset.html.twig" %}', [
            'name' => $fullname,
            'author' => $author,
            'reset_link' =>$reset_link
        ]);

        $message = $this->grav['Email']->message($subject, $body, 'text/html')
            ->setFrom($from)
            ->setTo($to);

        $sent = $this->grav['Email']->send($message);

        if ($sent < 1) {
            $this->admin->setMessage('Failed to email instructions, please try again later.');
        } else {
            $this->admin->setMessage('Instructions to reset your password have been sent by email.');
        }

        $this->setRedirect('/');
        return true;
    }

    public function taskReset()
    {
        $data = $this->post;

        if (isset($data['password'])) {

            $username = isset($data['username']) ? $data['username'] : null;
            $user = !empty($username) ? User::load($username) : null;
            $password = isset($data['password']) ? $data['password'] : null;
            $token = isset($data['token']) ? $data['token'] : null;

            if (!empty($user) && $user->exists() && !empty($user->reset)) {
                list($good_token, $expire) = explode('::', $user->reset);

                if ($good_token === $token) {

                    if (time() > $expire) {
                        $this->admin->setMessage('Reset link has expired, please try again.');
                        $this->setRedirect('/forgot');
                        return true;
                    }


                    unset($user->hashed_password);
                    unset($user->reset);
                    $user->password = $password;
                    $user->save();

                    $this->admin->setMessage('Password has been reset.');
                    $this->setRedirect('/');
                    return true;
                }
            }

            $this->admin->setMessage('Invalid reset link used, please try again.');
            $this->setRedirect('/forgot');
            return true;

        } else {
            $user = $this->grav['uri']->param('user');
            $token = $this->grav['uri']->param('token');

            if (empty($user) || empty($token)) {
                $this->admin->setMessage('Invalid reset link used, please try again.');
                $this->setRedirect('/forgot');
                return true;
            }

            $this->admin->forgot = [ 'username' => $user, 'token' => $token ];
        }

        return true;
    }

    protected function taskClearCache()
    {
        $results = Cache::clearCache('standard');
        if (count($results) > 0) {
            $this->admin->json_response = ['success', 'Cache cleared'];
        } else {
            $this->admin->json_response = ['error', 'Error clearing cache'];
        }

        return true;
    }

    protected function taskListmedia()
    {
        $page = $this->admin->page(true);

        if (!$page) {
            $this->admin->json_response = ['error', 'No Page found'];
            return false;
        }

        $media_list = array();
        foreach ($page->media()->all() as $name => $media) {
            $media_list[$name] = ['url' => $media->cropZoom(150, 100)->url(),'size' => $media->get('size')];
        }
        $this->admin->media = $media_list;

        return true;
    }

    protected function taskAddmedia()
    {
        $page = $this->admin->page(true);

        /** @var Config $config */
        $config = $this->grav['config'];

        if (!isset($_FILES['file']['error']) || is_array($_FILES['file']['error'])) {
            $this->admin->json_response = ['error', 'Invalid Parameters'];
            return;
        }

        // Check $_FILES['file']['error'] value.
        switch ($_FILES['file']['error']) {
            case UPLOAD_ERR_OK:
                break;
            case UPLOAD_ERR_NO_FILE:
                $this->admin->json_response = ['error', 'No files sent'];
                return;
            case UPLOAD_ERR_INI_SIZE:
            case UPLOAD_ERR_FORM_SIZE:
                $this->admin->json_response = ['error', 'Exceeded filesize limit.'];
                return;
            default:
                $this->admin->json_response = ['error', 'Unkown errors'];
                return;
        }

        // You should also check filesize here.
        if ($_FILES['file']['size'] > 1000000) {
            $this->admin->json_response = ['error', 'Exceeded filesize limit.'];
            return;
        }


        // Check extension
        $fileParts = pathinfo($_FILES['file']['name']);
        $fileExt = strtolower($fileParts['extension']);

        // If not a supported type, return
        if (!$config->get("media.{$fileExt}")) {
            $this->admin->json_response = ['error', 'Unsupported file type: '.$fileExt];
            return;
        }


        // Upload it
        if (!move_uploaded_file($_FILES['file']['tmp_name'], sprintf('%s/%s', $page->path(), $_FILES['file']['name']))) {
            $this->admin->json_response = ['error', 'Failed to move uploaded file.'];
            return;
        }

        $this->admin->json_response = ['success', 'File uploaded successfully'];

        return;
    }

    protected function taskDelmedia()
    {
        $page = $this->admin->page(true);

        if (!$page) {
            $this->admin->json_response = ['error', 'No Page found'];
            return false;
        }

        $filename = !empty($this->post['filename']) ? $this->post['filename'] : null;
        if ($filename) {
            $targetPath = $page->path().'/'.$filename;

            if (file_exists($targetPath)) {
                if (unlink($targetPath)) {
                    $this->admin->json_response = ['success', 'File deleted: '.$filename];
                } else {
                    $this->admin->json_response = ['error', 'File could not be deleted: '.$filename];
                }
            } else {
                $this->admin->json_response = ['error', 'File not found: '.$filename];
            }
        } else {
            $this->admin->json_response = ['error', 'No file found'];
        }
        return true;
    }

    /**
     * Enable plugin.
     *
     * @return bool True if the action was performed.
     */
    public function taskEnable()
    {
        if ($this->view != 'plugins') {
            return false;
        }

        // Filter value and save it.
        $this->post = array('enabled' => 1, '_redirect' => 'plugins');
        $obj = $this->prepareData();
        $obj->save();
        $this->admin->setMessage('Successfully enabled plugin');

        return true;
    }

    /**
     * Enable plugin.
     *
     * @return bool True if the action was performed.
     */
    public function taskDisable()
    {
        if ($this->view != 'plugins') {
            return false;
        }

        // Filter value and save it.
        $this->post = array('enabled' => 0, '_redirect' => 'plugins');
        $obj = $this->prepareData();
        $obj->save();
        $this->admin->setMessage('Successfully disabled plugin');

        return true;
    }

    /**
     * Set default theme.
     *
     * @return bool True if the action was performed.
     */
    public function taskActivate()
    {
        if ($this->view != 'themes') {
            return false;
        }

        $this->post = array('_redirect' => 'themes');

        // Make sure theme exists (throws exception)
        $name = $this->route;
        $this->grav['themes']->get($name);

        // Store system configuration.
        $system = $this->admin->data('system');
        $system->set('pages.theme', $name);
        $system->save();

        // Force configuration reload and save.
        /** @var Config $config */
        $config = $this->grav['config'];
        $config->reload()->save();

        // TODO: find out why reload and save doesn't always update the object itself (and remove this workaround).
        $config->set('system.pages.theme', $name);

        $this->admin->setMessage('Successfully changed default theme.');

        return true;
    }

    /**
     * Handles installing plugins and themes
     *
     * @return bool True is the action was performed
     */
    public function taskInstall()
    {
        require_once __DIR__ . '/gpm.php';

        $package = $this->route;

        $result = \Grav\Plugin\Admin\Gpm::install($package, []);

        if ($result) {
            $this->admin->setMessage("Installation successful.");
        } else {
            $this->admin->setMessage("Installation failed.");
        }

        $this->post = array('_redirect' => $this->view . '/' . $this->route);

        return true;
    }

    /**
     * Handles updating plugins and themes
     *
     * @return bool True is the action was performed
     */
    public function taskUpdate()
    {
        require_once __DIR__ . '/gpm.php';

        $package = $this->route;

        // Update multi mode
        if (!$package) {
            $package = [];

            if ($this->view === 'plugins' || $this->view === 'update') {
                $package = $this->admin->gpm()->getUpdatablePlugins();
            }

            if ($this->view === 'themes' || $this->view === 'update') {
                $package = array_merge($package, $this->admin->gpm()->getUpdatableThemes());
            }
        }

        $result = \Grav\Plugin\Admin\Gpm::update($package, []);

        if ($this->view === 'update') {

            if ($result) {
                $this->admin->json_response = ['success', 'Everything updated'];
            } else {
                $this->admin->json_response = ['error', 'Updates failed'];
            }

        } else {
            if ($result) {
                $this->admin->setMessage("Installation successful.");
            } else {
                $this->admin->setMessage("Installation failed.");
            }

            $this->post = array('_redirect' => $this->view . '/' . $this->route);
        }

        return true;
    }

    /**
     * Handles uninstalling plugins and themes
     *
     * @return bool True is the action was performed
     */
    public function taskUninstall()
    {
        require_once __DIR__ . '/gpm.php';

        $package = $this->route;

        $result = \Grav\Plugin\Admin\Gpm::uninstall($package, []);

        if ($result) {
            $this->admin->setMessage("Uninstall successful.");
        } else {
            $this->admin->setMessage("Uninstall failed.");
        }

        $this->post = array('_redirect' => $this->view);

        return true;
    }

    /**
     * Handles form and saves the input data if its valid.
     *
     * @return bool True if the action was performed.
     */
    public function taskSave()
    {
        $data = $this->post;

        // Special handler for pages data.
        if ($this->view == 'pages') {
            /** @var Page\Pages $pages */
            $pages = $this->grav['pages'];

            // Find new parent page in order to build the path.
            $route = !isset($data['route']) ? dirname($this->admin->route) : $data['route'];
            $parent = $route && $route != '/' ? $pages->dispatch($route, true) : $pages->root();
            $obj = $this->admin->page(true);

            // Change parent if needed and initialize move (might be needed also on ordering/folder change).
            $obj = $obj->move($parent);
            $this->preparePage($obj);

            // Reset slug and route. For now we do not support slug twig variable on save.
            $obj->slug('');


        } else {
            // Handle standard data types.
            $obj = $this->prepareData();
        }
        if ($obj) {
            $obj->validate();
            $obj->filter();
            $obj->save();
            $this->admin->setMessage('Successfully saved');
        }

        if ($this->view != 'pages') {
            // Force configuration reload.
            /** @var Config $config */
            $config = $this->grav['config'];
            $config->reload();

            if ($this->view === 'users') {
                $this->grav['user']->merge(User::load($this->admin->route)->toArray());
            }
        }

        // Redirect to new location.
        if ($obj instanceof Page\Page && $obj->route() != $this->admin->route()) {
            $this->setRedirect($this->view . '/' . $obj->route());
        }

        return true;
    }


    /**
     * Continue to the new page.
     *
     * @return bool True if the action was performed.
     */
    public function taskContinue()
    {
        if ($this->view == 'users') {
            $this->setRedirect("{$this->view}/{$this->post['username']}");
            return true;
        }

        if ($this->view != 'pages') {
            return false;
        }

        $data = $this->post;
        $route = $data['route'] != '/' ? $data['route'] : '';
        $folder = ltrim($data['folder'], '_');
        if (!empty($data['modular'])) {
            $folder = '_' . $folder;
        }
        $path = $route . '/' . $folder;

        $this->admin->session()->{$path} = $data;
        $this->setRedirect("{$this->view}/{$path}");

        return true;
    }

    /**
     * Save page as a new copy.
     *
     * @return bool True if the action was performed.
     * @throws \RuntimeException
     */
    protected function taskCopy()
    {
        // Only applies to pages.
        if ($this->view != 'pages') {
            return false;
        }

        try {
            /** @var Page\Pages $pages */
            $pages = $this->grav['pages'];
            $data = $this->post;

            // Find new parent page in order to build the path.
            $parent = empty($data['route']) ? $pages->root() : $pages->dispatch($data['route'], true);

            // And then get the current page.
            $page = $this->admin->page(true);

            // Make a copy of the current page and fill the updated information into it.
            $page = $page->copy($parent);
            $this->preparePage($page);

            // Deal with folder naming conflicts, but limit number of searches to 99.
            $break = 99;
            while ($break > 0 && file_exists($page->filePath())) {
                $break--;
                $match = preg_split('/-(\d+)$/', $page->path(), 2, PREG_SPLIT_DELIM_CAPTURE);
                $page->path($match[0] . '-' . (isset($match[1]) ? (int) $match[1] + 1 : 2));
                // Reset slug and route. For now we do not support slug twig variable on save.
                $page->slug('');
            }

            // Validation, type filtering and saving the changes.
            $page->validate();
            $page->filter();
            $page->save();

            // Enqueue message and redirect to new location.
            $this->admin->setMessage('Successfully copied');
            $this->setRedirect($this->view . '/' . $page->route());

        } catch (\Exception $e) {
            throw new \RuntimeException('Copying page failed on error: ' . $e->getMessage());
        }

        return true;
    }

    /**
     * Reorder pages.
     *
     * @return bool True if the action was performed.
     */
    protected function taskReorder()
    {
        // Only applies to pages.
        if ($this->view != 'pages') {
            return false;
        }

        $this->admin->setMessage('Reordering was successful');
        return true;
    }

    /**
     * Delete page.
     *
     * @return bool True if the action was performed.
     * @throws \RuntimeException
     */
    protected function taskDelete()
    {
        // Only applies to pages.
        if ($this->view != 'pages') {
            return false;
        }

        /** @var Uri $uri */
        $uri = $this->grav['uri'];

        try {
            $page = $this->admin->page();
            Folder::delete($page->path());

            // Set redirect to either referrer or pages list.
            $redirect = $uri->referrer();
            if ($redirect == $uri->route()) {
                $redirect = 'pages';
            }

            $this->admin->setMessage('Successfully deleted');
            $this->setRedirect($redirect);

        } catch (\Exception $e) {
            throw new \RuntimeException('Deleting page failed on error: ' . $e->getMessage());
        }

        return true;
    }

    /**
     * Prepare and return POST data.
     *
     * @param array $post
     * @return array
     */
    protected function &getPost($post)
    {
        unset($post['task']);

        // Decode JSON encoded fields and merge them to data.
        if (isset($post['_json'])) {
            $post = array_merge_recursive($post, $this->jsonDecode($post['_json']));
            unset($post['_json']);
        }
        return $post;
    }

    /**
     * Recursively JSON decode data.
     *
     * @param  array $data
     * @return array
     */
    protected function jsonDecode(array $data)
    {
        foreach ($data as &$value) {
            if (is_array($value)) {
                $value = $this->jsonDecode($value);
            } else {
                $value = json_decode($value, true);
            }
        }
        return $data;
    }

    protected function setRedirect($path, $code = 303)
    {
        $this->redirect = $path;
        $this->code = $code;
    }

    protected function prepareData()
    {
        $type = trim("{$this->view}/{$this->admin->route}", '/');
        $data = $this->admin->data($type, $this->post);

        return $data;
    }

    protected function preparePage(\Grav\Common\Page\Page $page)
    {
        $input = $this->post;

        $order = max(0, (int) isset($input['order']) ? $input['order'] : $page->value('order'));
        $ordering = $order ? sprintf('%02d.', $order) : '';
        $slug = empty($input['folder']) ? $page->value('folder') : (string) $input['folder'];
        $page->folder($ordering . $slug);

        if (isset($input['type'])) {
            $type = (string) $input['type'];
            $name = preg_replace('|.*/|', '', $type) . '.md';
            $page->name($name);
            $page->template($type);
        }

        // special case for Expert mode build the raw, unset content
        if (isset($input['frontmatter']) && isset($input['content'])) {
            $page->raw("---\n" . (string) $input['frontmatter'] . "\n---\n" . (string) $input['content']);
            unset($input['content']);
        }

        if (isset($input['header'])) {
            $page->header((object) $input['header']);
        }
        // Fill content last because of it also renders the output.
        if (isset($input['content'])) {
            $page->content((string) $input['content']);
        }
    }
}