<?php

namespace SilverStripe\Comments\Controllers;

use SilverStripe\CMS\Model\SiteTree;
use SilverStripe\Comments\Extensions\CommentsExtension;
use SilverStripe\Comments\Forms\CommentForm;
use SilverStripe\Comments\Model\Comment;
use SilverStripe\Control\Controller;
use SilverStripe\Control\Director;
use SilverStripe\Control\HTTP;
use SilverStripe\Control\HTTPRequest;
use SilverStripe\Control\HTTPResponse;
use SilverStripe\Control\HTTPResponse_Exception;
use SilverStripe\Control\RSS\RSSFeed;
use SilverStripe\Core\Injector\Injector;
use SilverStripe\Forms\Form;
use SilverStripe\ORM\DataObject;
use SilverStripe\ORM\FieldType\DBHTMLText;
use SilverStripe\ORM\PaginatedList;
use SilverStripe\Security\Security;
use SilverStripe\Control\Middleware\HTTPCacheControlMiddleware;

/**
 * @package comments
 */
class CommentingController extends Controller
{
    /**
     * {@inheritDoc}
     */
    private static $allowed_actions = [
        'delete',
        'spam',
        'ham',
        'approve',
        'rss',
        'CommentsForm',
        'reply',
        'doPostComment',
        'doPreviewComment',
    ];

    /**
     * {@inheritDoc}
     */
    private static $url_handlers = [
        'reply/$ParentCommentID//$ID/$OtherID' => 'reply',
    ];

    /**
     * Fields required for this form
     *
     * @var array
     * @config
     */
    private static $required_fields = [
        'Name',
        'Email',
        'Comment',
    ];

    /**
     * Parent class this commenting form is for
     *
     * @var string
     */
    private $parentClass = '';

    /**
     * The record this commenting form is for
     *
     * @var DataObject
     */
    private $ownerRecord;

    /**
     * Parent controller record
     *
     * @var Controller
     */
    private $ownerController;

    /**
     * Backup url to return to
     *
     * @var string
     */
    protected $fallbackReturnURL;

    /**
     * Set the parent class name to use
     *
     * @param string $class
     */
    public function setParentClass($class)
    {
        $this->parentClass = $this->encodeClassName($class);
    }

    /**
     * Get the parent class name used
     *
     * @return string
     */
    public function getParentClass()
    {
        return $this->decodeClassName($this->parentClass);
    }

    /**
     * Encode a fully qualified class name to a URL-safe version
     *
     * @param string $input
     * @return string
     */
    public function encodeClassName($input)
    {
        return str_replace('\\', '-', $input ?? '');
    }

    /**
     * Decode an "encoded" fully qualified class name back to its original
     *
     * @param string $input
     * @return string
     */
    public function decodeClassName($input)
    {
        return str_replace('-', '\\', $input ?? '');
    }

    /**
     * Set the record this controller is working on
     *
     * @param DataObject $record
     */
    public function setOwnerRecord($record)
    {
        $this->ownerRecord = $record;
    }

    /**
     * Get the record
     *
     * @return DataObject
     */
    public function getOwnerRecord()
    {
        return $this->ownerRecord;
    }

    /**
     * Set the parent controller
     *
     * @param Controller $controller
     */
    public function setOwnerController($controller)
    {
        $this->ownerController = $controller;
    }

    /**
     * Get the parent controller
     *
     * @return Controller
     */
    public function getOwnerController()
    {
        return $this->ownerController;
    }

    /**
     * Get the commenting option for the current state
     *
     * @param string $key
     * @return mixed Result if the setting is available, or null otherwise
     */
    public function getOption($key)
    {
        // If possible use the current record
        if ($record = $this->getOwnerRecord()) {
            /** @var DataObject|CommentsExtension $record */
            return $record->getCommentsOption($key);
        }

        // Otherwise a singleton of that record
        if ($class = $this->getParentClass()) {
            return singleton($class)->getCommentsOption($key);
        }

        // Otherwise just use the default options
        return singleton(CommentsExtension::class)->getCommentsOption($key);
    }

    /**
     * Returns all the commenting options for the current instance.
     *
     * @return array
     */
    public function getOptions()
    {
        if ($record = $this->getOwnerRecord()) {
            /** @var DataObject|CommentsExtension $record */
            return $record->getCommentsOptions();
        }

        // Otherwise a singleton of that record
        if ($class = $this->getParentClass()) {
            return singleton($class)->getCommentsOptions();
        }

        // Otherwise just use the default options
        return singleton(CommentsExtension::class)->getCommentsOptions();
    }

    /**
     * Workaround for generating the link to this controller
     *
     * @param  string $action
     * @param  int    $id
     * @param  string $other
     * @return string
     */
    public function Link($action = '', $id = '', $other = '')
    {
        return Controller::join_links(Director::baseURL(), 'comments', $action, $id, $other);
    }

    /**
     * Outputs the RSS feed of comments
     *
     * @return DBHTMLText
     */
    public function rss()
    {
        return $this->getFeed($this->request)->outputToBrowser();
    }

    /**
     * Return an RSSFeed of comments for a given set of comments or all
     * comments on the website.
     *
     * @param HTTPRequest
     *
     * @return RSSFeed
     */
    public function getFeed(HTTPRequest $request)
    {
        $link = $this->Link('rss');
        $class = $this->decodeClassName($request->param('ID'));
        $id = $request->param('OtherID');

        // Support old pageid param
        if (!$id && !$class && ($id = $request->getVar('pageid'))) {
            $class = SiteTree::class;
        }

        $comments = Comment::get()->filter([
            'Moderated' => 1,
            'IsSpam' => 0,
        ]);

        // Check if class filter
        if ($class) {
            if (!is_subclass_of($class, DataObject::class) || !$class::has_extension(CommentsExtension::class)) {
                return $this->httpError(404);
            }
            $this->setParentClass($class);
            $comments = $comments->filter('ParentClass', $class);
            $link = Controller::join_links($link, $this->encodeClassName($class));

            // Check if id filter
            if ($id) {
                $comments = $comments->filter('ParentID', $id);
                $link = Controller::join_links($link, $id);
                $this->setOwnerRecord(DataObject::get_by_id($class, $id));
            }
        }

        $title = _t(__CLASS__ . '.RSSTITLE', "Comments RSS Feed");
        $comments = PaginatedList::create($comments, $request);
        $comments->setPageLength($this->getOption('comments_per_page'));

        return RSSFeed::create(
            $comments,
            $link,
            $title,
            $link,
            'Title',
            'EscapedComment',
            'AuthorName'
        );
    }

    /**
     * Deletes a given {@link Comment} via the URL.
     */
    public function delete()
    {
        $comment = $this->getComment();
        if (!$comment) {
            return $this->httpError(404);
        }
        if (!$comment->canDelete()) {
            return Security::permissionFailure($this, 'You do not have permission to delete this comment');
        }
        if (!$comment->getSecurityToken()->checkRequest($this->request)) {
            return $this->httpError(400);
        }

        $comment->delete();

        return $this->request->isAjax()
            ? true
            : $this->redirectBack();
    }

    /**
     * Marks a given {@link Comment} as spam. Removes the comment from display
     */
    public function spam()
    {
        $comment = $this->getComment();
        if (!$comment) {
            return $this->httpError(404);
        }
        if (!$comment->canEdit()) {
            return Security::permissionFailure($this, 'You do not have permission to edit this comment');
        }
        if (!$comment->getSecurityToken()->checkRequest($this->request)) {
            return $this->httpError(400);
        }

        $comment->markSpam();
        return $this->renderChangedCommentState($comment);
    }

    /**
     * Marks a given {@link Comment} as ham (not spam).
     */
    public function ham()
    {
        $comment = $this->getComment();
        if (!$comment) {
            return $this->httpError(404);
        }
        if (!$comment->canEdit()) {
            return Security::permissionFailure($this, 'You do not have permission to edit this comment');
        }
        if (!$comment->getSecurityToken()->checkRequest($this->request)) {
            return $this->httpError(400);
        }

        $comment->markApproved();
        return $this->renderChangedCommentState($comment);
    }

    /**
     * Marks a given {@link Comment} as approved.
     */
    public function approve()
    {
        $comment = $this->getComment();
        if (!$comment) {
            return $this->httpError(404);
        }
        if (!$comment->canEdit()) {
            return Security::permissionFailure($this, 'You do not have permission to approve this comment');
        }
        if (!$comment->getSecurityToken()->checkRequest($this->request)) {
            return $this->httpError(400);
        }
        $comment->markApproved();
        return $this->renderChangedCommentState($comment);
    }

    /**
     * Redirect back to referer if available, ensuring that only site URLs
     * are allowed to avoid phishing.  If it's an AJAX request render the
     * comment in it's new state
     *
     * @param Comment $comment
     * @return DBHTMLText|HTTPResponse|false
     */
    private function renderChangedCommentState($comment)
    {
        $referer = $this->request->getHeader('Referer');

        // Render comment using AJAX
        if ($this->request->isAjax()) {
            return $comment->renderWith('Includes/CommentsInterface_singlecomment');
        }

        // Redirect to either the comment or start of the page
        if (empty($referer)) {
            return $this->redirectBack();
        }

        // Redirect to the comment, but check for phishing
        $url = $referer . '#comment-' . $comment->ID;
        // absolute redirection URLs not located on this site may cause phishing
        if (Director::is_site_url($url)) {
            return $this->redirect($url);
        }

        return false;
    }

    /**
     * Returns the comment referenced in the URL (by ID). Permission checking
     * should be done in the callee.
     *
     * @return Comment|false
     */
    public function getComment()
    {
        $id = isset($this->urlParams['ID']) ? $this->urlParams['ID'] : false;

        if ($id) {
            /** @var Comment $comment */
            $comment = Comment::get()->byId($id);
            if ($comment) {
                $this->fallbackReturnURL = $comment->Link();
                return $comment;
            }
        }

        return false;
    }

    /**
     * Create a reply form for a specified comment
     *
     * @param  Comment $comment
     * @return Form
     */
    public function ReplyForm($comment)
    {
        // Enables multiple forms with different names to use the same handler
        $form = $this->CommentsForm();
        $form->setName('ReplyForm_' . $comment->ID);
        $form->setHTMLID(null);
        $form->addExtraClass('reply-form');

        // Load parent into reply form
        $form->loadDataFrom([
            'ParentCommentID' => $comment->ID
        ]);

        // Customise action
        $form->setFormAction($this->Link('reply', $comment->ID));

        $this->extend('updateReplyForm', $form);

        return $form;
    }


    /**
     * Request handler for reply form.
     *
     * This method will disambiguate multiple reply forms in the same method
     *
     * @param  HTTPRequest $request
     * @throws HTTPResponse_Exception
     */
    public function reply(HTTPRequest $request)
    {
        // Extract parent comment from reply and build this way
        if ($parentID = $request->param('ParentCommentID')) {
            /** @var Comment $comment */
            $comment = DataObject::get_by_id(Comment::class, $parentID, true);
            if ($comment) {
                return $this->ReplyForm($comment);
            }
        }
        return $this->httpError(404);
    }

    /**
     * Post a comment form
     *
     * @return Form
     */
    public function CommentsForm()
    {
        $form = Injector::inst()->create(CommentForm::class, __FUNCTION__, $this);

        // hook to allow further extensions to alter the comments form
        $this->extend('alterCommentForm', $form);

        return $form;
    }


    /**
     * @return HTTPResponse|false
     */
    public function redirectBack()
    {
        // Don't cache the redirect back ever
        HTTPCacheControlMiddleware::singleton()->setMaxAge(0);

        $url = null;

        // In edge-cases, this will be called outside of a handleRequest() context; in that case,
        // redirect to the homepage - don't break into the global state at this stage because we'll
        // be calling from a test context or something else where the global state is inappropraite
        if ($this->request) {
            if ($this->request->requestVar('BackURL')) {
                $url = $this->request->requestVar('BackURL');
            } elseif ($this->request->isAjax() && $this->request->getHeader('X-Backurl')) {
                $url = $this->request->getHeader('X-Backurl');
            } elseif ($this->request->getHeader('Referer')) {
                $url = $this->request->getHeader('Referer');
            }
        }

        if (!$url) {
            $url = $this->fallbackReturnURL;
        }
        if (!$url) {
            $url = Director::baseURL();
        }

        // absolute redirection URLs not located on this site may cause phishing
        if (Director::is_site_url($url)) {
            return $this->redirect($url);
        }

        return false;
    }
}