<?php

/**
 * Blog Holder
 *
 * @package silverstripe
 * @subpackage blog
 *
 * @method HasManyList Tags() List of tags in this blog
 * @method HasManyList Categories() List of categories in this blog
 * @method ManyManyList Editors() List of editors
 * @method ManyManyList Writers() List of writers
 * @method ManyManyList Contributors() List of contributors
 *
 * @author Michael Strong <github@michaelstrong.co.uk>
 **/
class Blog extends Page implements PermissionProvider {

	/**
	 * Permission for user management
	 *
	 * @var string
	 */
	const MANAGE_USERS = 'BLOG_MANAGE_USERS';

	/**
	 * If true, users assigned as editor, writer, or contributor will be automatically
	 * granted CMS_ACCESS_CMSMain permission. If false, only users with this permission
	 * already may be assigned.
	 *
	 * @var boolean
	 * @config
	 */
	private static $grant_user_access = true;

	/**
	 * Permission to either require, or grant to users assigned to work on this blog
	 *
	 * @var string
	 * @config
	 */
	private static $grant_user_permission = 'CMS_ACCESS_CMSMain';

	/**
	 * Group code to assign newly granted users toh
	 *
	 * @var string
	 * @config
	 */
	private static $grant_user_group = 'blog-users';

	private static $db = array(
		"PostsPerPage" => "Int",
	);

	private static $has_many = array(
		"Tags" => "BlogTag",
		"Categories" => "BlogCategory",
	);

	private static $many_many = array(
		'Editors' => 'Member',
		'Writers' => 'Member',
		'Contributors' => 'Member',
	);

	private static $allowed_children = array(
		"BlogPost",
	);

	private static $extensions = array(
		"BlogFilter",
	);

	private static $defaults = array(
		"ProvideComments" => false,
	);

	private static $description = 'Adds a blog to your website.';

	public function getCMSFields() {
		Requirements::css(BLOGGER_DIR . '/css/cms.css');
		Requirements::javascript(BLOGGER_DIR . '/js/expandable-help-text.js');
		Requirements::javascript(BLOGGER_DIR . '/js/merge-action.js');

		$self =& $this;

		$this->beforeUpdateCMSFields(function ($fields) use ($self) {
			if(!$self->canEdit()) {
				return;
			}

			$categories = GridField::create(
				"Categories",
				_t("Blog.Categories", "Categories"),
				$self->Categories(),
				GridFieldCategorisationConfig::create(15, $self->Categories(), 'BlogCategory', 'Categories', 'BlogPosts')
			);

			$tags = GridField::create(
				"Tags",
				_t("Blog.Tags", "Tags"),
				$self->Tags(),
				GridFieldCategorisationConfig::create(15, $self->Categories(), 'BlogTag', 'Tags', 'BlogPosts')
			);

			$fields->addFieldsToTab("Root.Categorisation", array(
				$categories,
				$tags
			));
		});

		$fields = parent::getCMSFields();

		return $fields;
	}

	/**
	 * Check if this member is an editor of the blog
	 *
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function isEditor($member) {
		$isEditor = $this->isMemberOf($member, $this->Editors());
		$this->extend('updateIsEditor', $isEditor, $member);
		return $isEditor;
	}

	/**
	 * Check if this member is a writer of the blog
	 *
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function isWriter($member) {
		$isWriter = $this->isMemberOf($member, $this->Writers());
		$this->extend('updateIsWriter', $isWriter, $member);
		return $isWriter;
	}

	/**
	 * Check if this member is a contributor of the blog
	 *
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function isContributor($member) {
		$isContributor = $this->isMemberOf($member, $this->Contributors());
		$this->extend('updateIsContributor', $isContributor, $member);
		return $isContributor;
	}

	/**
	 * Determine the role of the given member
	 * Call be called via template to determine the current user
	 *
	 * E.g. `Hello $RoleOf($CurrentMember.ID)`
	 *
	 * @param Member|integer $member
	 *
	 * @return string|null Author, Editor, Writer, Contributor, or null if no role
	 */
	public function RoleOf($member) {
		if(is_numeric($member)) $member = DataObject::get_by_id('Member', $member);
		if(!$member) return null;

		// Check each role
		if($this->isEditor($member)) return _t('Blog.EDITOR', 'Editor');
		if($this->isWriter($member)) return _t('Blog.WRITER', 'Writer');
		if($this->isContributor($member)) return _t('Blog.CONTRIBUTOR', 'Contributor');
	}

	/**
	 * Determine if the given member belongs to the given subrelation
	 *
	 * @param Member $member
	 * @param DataList $list Relation to check
	 *
	 * @return boolean
	 */
	protected function isMemberOf($member, $list) {
		if(!$member || !$member->exists()) return false;

		if($list instanceof UnsavedRelationList) {
			return in_array($member->ID, $list->getIDList());
		}

		return $list->byID($member->ID) !== null;
	}


	public function canEdit($member = null) {
		$member = $member ?: Member::currentUser();
		if(is_numeric($member)) $member = Member::get()->byID($member);

		// Allow editors to edit this page
		if($this->isEditor($member)) return true;

		return parent::canEdit($member);
	}

	/**
	 * Determine if this user can edit the editors list
	 *
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function canEditEditors($member = null) {
		$member = $member ?: Member::currentUser();

		$extended = $this->extendedCan('canEditEditors', $member);
		if($extended !== null) return $extended;

		// Check permission
		return Permission::checkMember($member, self::MANAGE_USERS);
	}

	/**
	 * Determine if this user can edit writers list
	 *
	 * @param Member $member
	 *
	 * @return boolean
	 */
	public function canEditWriters($member = null) {
		$member = $member ?: Member::currentUser();
		if(is_numeric($member)) $member = Member::get()->byID($member);

		$extended = $this->extendedCan('canEditWriters', $member);
		if($extended !== null) return $extended;

		// Editors can edit writers
		if($this->isEditor($member)) return true;

		// Check permission
		return Permission::checkMember($member, self::MANAGE_USERS);
	}

	/**
	 * Determines if this user can edit the contributors list
	 *
	 * @param type $member
	 *
	 * @return boolean
	 */
	public function canEditContributors($member = null) {
		$member = $member ?: Member::currentUser();
		if(is_numeric($member)) $member = Member::get()->byID($member);

		$extended = $this->extendedCan('canEditContributors', $member);
		if($extended !== null) return $extended;

		// Editors can edit writers
		if($this->isEditor($member)) return true;

		// Check permission
		return Permission::checkMember($member, self::MANAGE_USERS);
	}

	public function canAddChildren($member = null) {
		$member = $member ?: Member::currentUser();
		if(is_numeric($member)) $member = Member::get()->byID($member);

		// Editors, Writers and Contributors can add children
		if($this->isEditor($member) || $this->isWriter($member) || $this->isContributor($member)) {
			return true;
		}

		return parent::canAddChildren($member);
	}


	public function getSettingsFields() {
		$fields = parent::getSettingsFields();
		$fields->addFieldToTab("Root.Settings",
			NumericField::create("PostsPerPage", _t("Blog.PostsPerPage", "Posts Per Page"))
		);

		// Roles and Permissions
		$members = $this->getCandidateUsers()->map()->toArray();

		// Editors
		$editorField = ListboxField::create('Editors', 'Editors', $members)
			->setMultiple(true)
			->setRightTitle('<a class="toggle-description">help</a>')
			->setDescription('
				An editor has control over specific Blogs, and all posts included within it. Short of being able to assign other editors to a blog, they are able to handle most changes to their assigned blog.<br />
				<br />
				Editors have these permissions:<br />
				<br />
				Update or publish any BlogPost in their Blog<br />
				Update or publish their Blog<br />
				Assign/unassign writers to their Blog<br />
				Assign/unassign contributors to their Blog<br />
				Assign/unassign any member as an author of a particular BlogPost
			');

		if(!$this->canEditEditors()) {
			$editorField = $editorField->performDisabledTransformation();
		}

		// Writers
		$writerField = ListboxField::create('Writers', 'Writers', $members)
			->setMultiple(true)
			->setRightTitle('<a class="toggle-description">help</a>')
			->setDescription('
				A writer has full control over creating, editing and publishing BlogPosts they have authored or have been assigned to. Writers are unable to edit BlogPosts to which they are not assigned.<br />
				<br />
				Writers have these permissions:<br />
				<br />
				Update or publish any BlogPost they have authored or have been assigned to<br />
				Assign/unassign any member as an author of a particular BlogPost they have authored or have been assigned to
			');

		if(!$this->canEditWriters()) {
			$writerField = $writerField->performDisabledTransformation();
		}

		// Contributors
		$contributorField = ListboxField::create('Contributors', 'Contributors', $members)
			->setMultiple(true)
			->setRightTitle('<a class="toggle-description">help</a>')
			->setDescription('
				Contributors have the ability to create or edit BlogPosts, but are unable to publish without authorisation of an editor. They are also unable to assign other contributing authors to any of their BlogPosts.<br />
				<br />
				Contributors have these permissions:<br />
				<br />
				Update any BlogPost they have authored or have been assigned to
			');

		if(!$this->canEditContributors()) {
			$contributorField = $contributorField->performDisabledTransformation();
		}

		$fields->addFieldsToTab('Root.Users', array(
			$editorField,
			$writerField,
			$contributorField
		));

		return $fields;
	}


	/**
	 * Return blog posts
	 *
	 * @return DataList of BlogPost objects
	 **/
	public function getBlogPosts() {
		$blogPosts = BlogPost::get()->filter("ParentID", $this->ID);
		//Allow decorators to manipulate list
		$this->extend('updateGetBlogPosts', $blogPosts);
		return $blogPosts;
	}


	/**
	 * Returns blogs posts for a given date period.
	 *
	 * @param $year int
	 * @param $month int
	 * @param $day int
	 *
	 * @return DataList
	 **/
	public function getArchivedBlogPosts($year, $month = null, $day = null) {
		$query = $this->getBlogPosts()->dataQuery();

		$stage = $query->getQueryParam("Versioned.stage");
		if($stage) $stage = '_' . Convert::raw2sql($stage);

		$query->innerJoin("BlogPost", "`SiteTree" . $stage . "`.`ID` = `BlogPost" . $stage . "`.`ID`");
		$query->where("YEAR(PublishDate) = '" . Convert::raw2sql($year) . "'");
		if($month) {
			$query->where("MONTH(PublishDate) = '" . Convert::raw2sql($month) . "'");
			if($day) {
				$query->where("DAY(PublishDate) = '" . Convert::raw2sql($day) . "'");
			}
		}

		return $this->getBlogPosts()->setDataQuery($query);
	}


	/**
	 * Get a link to a Member profile.
	 *
	 * @param urlSegment
	 *
	 * @return String
	 */
	public function ProfileLink($urlSegment) {
		return Controller::join_links($this->Link(), 'profile', $urlSegment);
	}


	/**
	 * This sets the title for our gridfield
	 *
	 * @return string
	 */
	public function getLumberjackTitle() {
		return _t('Blog.LumberjackTitle', 'Blog Posts');
	}


	/**
	 * This overwrites lumberjacks default gridfield config.
	 *
	 * @return GridFieldConfig
	 */
	public function getLumberjackGridFieldConfig() {
		return GridFieldConfig_BlogPost::create();
	}

	public function providePermissions() {
		return array(
			Blog::MANAGE_USERS => array(
				'name' => _t(
					'Blog.PERMISSION_MANAGE_USERS_DESCRIPTION',
					'Manage users for individual blogs'
				),
				'help' => _t(
					'Blog.PERMISSION_MANAGE_USERS_HELP',
					'Allow assignment of Editors, Writers, or Contributors to blogs'
				),
				'category' => _t('Blog.PERMISSIONS_CATEGORY', 'Blog permissions'),
				'sort' => 100
			)
		);
	}

	/**
	 * Gets the list of user candidates to be assigned to assist with this blog
	 *
	 * @return SS_List
	 */
	protected function getCandidateUsers() {
		if($this->config()->grant_user_access) {
			// If we are allowed to grant CMS access, all users are candidates
			return Member::get();
		} else {
			// If access cannot be granted, limit users to those who can access the CMS
			// This is useful for more secure sites
			$permission = $this->config()->grant_user_permission;
			return Permission::get_members_by_permission($permission);
		}
	}

	/**
	 * Gets or creates the group used to assign CMS access
	 *
	 * @return Group
	 */
	protected function getUserGroup() {
		$code = $this->config()->grant_user_group;
		$group = Group::get()->filter('Code', $code)->first();
		if($group) return $group;

		// Create new group
		$group = new Group();
		$group->Title = 'Blog users';
		$group->Code = $code;
		$group->write();

		// Add permission
		$permission = new Permission();
		$permission->Code = $this->config()->grant_user_permission;
		$group->Permissions()->add($permission);

		return $group;
	}

	protected function onBeforeWrite() {
		parent::onBeforeWrite();
		$this->assignGroup();
	}

	/**
	 * Assign users as necessary to the blog group
	 */
	protected function assignGroup() {
		// Ensure that any user granted editor, writer, or contributor have CMS_ACCESS_CMSMain access
		if(!$this->config()->grant_user_access) return;

		// Generate or retrieve the group
		$group = $this->getUserGroup();
		foreach(array($this->Editors(), $this->Writers(), $this->Contributors()) as $userlist) {
			foreach($userlist as $user) {
				// Ensure user exists in the group
				if(!$user->inGroup($group)) $user->Groups()->add($group);
			}
		}
	}

}


/**
 * Blog Controller
 *
 * @package silverstripe
 * @subpackage blog
 *
 * @author Michael Strong <github@michaelstrong.co.uk>
 **/
class Blog_Controller extends Page_Controller {

	private static $allowed_actions = array(
		'archive',
		'tag',
		'category',
		'rss',
		'profile'
	);

	private static $url_handlers = array(
		'tag/$Tag!' => 'tag',
		'category/$Category!' => 'category',
		'archive/$Year!/$Month/$Day' => 'archive',
		'profile/$URLSegment!' => 'profile'
	);

	private static $casting = array(
		'MetaTitle' => 'Text',
		'FilterDescription' => 'Text'
	);


	/**
	 * The current Blog Post DataList query.
	 *
	 * @var DataList
	 **/
	protected $blogPosts;


	public function index() {
		$this->blogPosts = $this->getBlogPosts();
		return $this->render();
	}

	/**
	 * Renders a Blog Member's profile.
	 *
	 * @return SS_HTTPResponse
	 **/
	public function profile() {
		$profile = $this->getCurrentProfile();

		if(!$profile) {
			return $this->httpError(404, 'Not Found');
		}

		$this->blogPosts = $this->getCurrentProfilePosts();

		return $this->render();
	}

	/**
	 * Get the Member associated with the current URL segment.
	 *
	 * @return Member|null
	 **/
	public function getCurrentProfile() {
		$urlSegment = $this->request->param('URLSegment');

		if($urlSegment) {
			return Member::get()
				->filter('URLSegment', $urlSegment)
				->first();
		}

		return null;
	}

	/**
	 * Get posts related to the current Member profile
	 *
	 * @return DataList|null
	 **/
	public function getCurrentProfilePosts() {
		$profile = $this->getCurrentProfile();

		if($profile) {
			return $profile->AuthoredPosts()->filter('ParentID', $this->ID);
		}

		return null;
	}

	/**
	 * Renders an archive for a specificed date. This can be by year or year/month
	 *
	 * @return SS_HTTPResponse
	 **/
	public function archive() {
		$year = $this->getArchiveYear();
		$month = $this->getArchiveMonth();
		$day = $this->getArchiveDay();

		// If an invalid month has been passed, we can return a 404.
		if($this->request->param("Month") && !$month) {
			return $this->httpError(404, "Not Found");
		}

		// Check for valid day
		if($month && $this->request->param("Day") && !$day) {
			return $this->httpError(404, "Not Found");
		}

		if($year) {
			$this->blogPosts = $this->getArchivedBlogPosts($year, $month, $day);
			return $this->render();
		}
		return $this->httpError(404, "Not Found");
	}


	/**
	 * Renders the blog posts for a given tag.
	 *
	 * @return SS_HTTPResponse
	 **/
	public function tag() {
		$tag = $this->getCurrentTag();
		if($tag) {
			$this->blogPosts = $tag->BlogPosts();
			return $this->render();
		}
		return $this->httpError(404, "Not Found");
	}


	/**
	 * Renders the blog posts for a given category
	 *
	 * @return SS_HTTPResponse
	 **/
	public function category() {
		$category = $this->getCurrentCategory();
		if($category) {
			$this->blogPosts = $category->BlogPosts();
			return $this->render();
		}
		return $this->httpError(404, "Not Found");
	}

	/**
	 * Get the meta title for the current action
	 *
	 * @return string
	 */
	public function getMetaTitle() {
		$title = $this->data()->getTitle();
		$filter = $this->getFilterDescription();
		if($filter) {
			$title = "{$title} - {$filter}";
		}

		$this->extend('updateMetaTitle', $title);
		return $title;
	}

	/**
	 * Returns a description of the current filter
	 *
	 * @return string
	 */
	public function getFilterDescription() {
		$items = array();

		// Check current page
		$list = $this->PaginatedList();
		$currentPage = $list->CurrentPage();

		// Build title
		if($currentPage > 1) {
			$items[] = _t(
				'Blog.FILTERDESCRIPTION_PAGE',
				"Page {page}",
				null,
				array('page' => $currentPage)
			);
		}

		// Check author
		if($author = $this->getCurrentProfile()) {
			$items[] = _t(
				'Blog.FILTERDESCRIPTION_AUTHOR',
				"By {author}",
				null,
				array('author' => $author->Title)
			);
		}

		// Check tag
		if($tag = $this->getCurrentTag()) {
			$items[] = _t(
				'Blog.FILTERDESCRIPTION_TAG',
				"Tagged with {tag}",
				null,
				array('tag' => $tag->Title)
			);
		}

		// Check category
		if($category = $this->getCurrentCategory()) {
			$items[] = _t(
				'Blog.FILTERDESCRIPTION_CATEGORY',
				"In category {category}",
				null,
				array('category' => $category->Title)
			);
		}

		// Check archive
		if($this->owner->getArchiveYear()) {
			if($this->owner->getArchiveDay()) {
				$date = $this->owner->getArchiveDate()->Nice();
			} elseif($this->owner->getArchiveMonth()) {
				$date = $this->owner->getArchiveDate()->format("F, Y");
			} else {
				$date = $this->owner->getArchiveDate()->format("Y");
			}
			$items[] = _t(
				'Blog.FILTERDESCRIPTION_DATE',
				"In {date}",
				null,
				array('date' => $date)
			);
		}

		$result = '';
		if($items) $result = implode(', ', $items);

		// Allow extension
		$this->extend('updateFilterDescription', $result);
		return $result;
	}


	/**
	 * Displays an RSS feed of blog posts
	 *
	 * @return string HTML
	 **/
	public function rss() {
		$rss = new RSSFeed($this->getBlogPosts(), $this->Link(), $this->MetaTitle, $this->MetaDescription);
		$this->extend('updateRss', $rss);
		return $rss->outputToBrowser();
	}


	/**
	 * Returns a list of paginated blog posts based on the blogPost dataList
	 *
	 * @return PaginatedList
	 **/
	public function PaginatedList() {
		$posts = new PaginatedList($this->blogPosts);

		// If pagination is set to '0' then no pagination will be shown.
		if($this->PostsPerPage > 0) {
			$posts->setPageLength($this->PostsPerPage);
		} else {
			$pageSize = $this->getBlogPosts()->count() ?: 99999;
			$posts->setPageLength($pageSize);
		}

		$start = $this->request->getVar($posts->getPaginationGetVar());
		$posts->setPageStart($start);

		return $posts;
	}


	/**
	 * Tag Getter for use in templates.
	 *
	 * @return BlogTag|null
	 **/
	public function getCurrentTag() {
		$tag = $this->request->param("Tag");
		if($tag) {
			return $this->dataRecord->Tags()
				->filter("URLSegment", $tag)
				->first();
		}
		return null;
	}


	/**
	 * Category Getter for use in templates.
	 *
	 * @return BlogCategory|null
	 **/
	public function getCurrentCategory() {
		$category = $this->request->param("Category");
		if($category) {
			return $this->dataRecord->Categories()
				->filter("URLSegment", $category)
				->first();
		}
		return null;
	}


	/**
	 * Fetches the archive year from the url
	 *
	 * @return int|null
	 **/
	public function getArchiveYear() {
		$year = $this->request->param("Year");
		if(preg_match("/^[0-9]{4}$/", $year)) {
			return (int) $year;
		}
		return null;
	}


	/**
	 * Fetches the archive money from the url.
	 *
	 * @return int|null
	 **/
	public function getArchiveMonth() {
		$month = $this->request->param("Month");
		if(preg_match("/^[0-9]{1,2}$/", $month)) {
			if($month > 0 && $month < 13) {
				// Check that we have a valid date.
				if(checkdate($month, 01, $this->getArchiveYear())) {
					return (int) $month;
				}
			}
		}
		return null;
	}


	/**
	 * Fetches the archive day from the url
	 *
	 * @return int|null
	 **/
	public function getArchiveDay() {
		$day = $this->request->param("Day");
		if(preg_match("/^[0-9]{1,2}$/", $day)) {

			// Check that we have a valid date
			if(checkdate($this->getArchiveMonth(), $day, $this->getArchiveYear())) {
				return (int) $day;
			}
		}
		return null;
	}


	/**
	 * Returns the current archive date.
	 *
	 * @return Date
	 **/
	public function getArchiveDate() {
		$year = $this->getArchiveYear();
		$month = $this->getArchiveMonth();
		$day = $this->getArchiveDay();

		if($year) {
			if($month) {
				$date = $year . '-' . $month . '-01';
				if($day) {
					$date = $year . '-' . $month . '-' . $day;
				}
			} else {
				$date = $year . '-01-01';
			}
			return DBField::create_field("Date", $date);
		}
	}


	/**
	 * Returns a link to the RSS feed.
	 *
	 * @return string URL
	 **/
	public function getRSSLink() {
		return $this->Link("rss");
	}

}