<?php
/**
 * Name: [Beta] Forum
 * Author: Sein Kraft <mail@seinkraft.info>
 *         Alpha <alpha@furries.com.ar>
 * License: GPLv2
 * Description: Rough forum extension
 * Documentation:
 */
/*
Todo:
*Quote buttons on posts
*Move delete and quote buttons away from each other
*Bring us on par with comment extension(post linking, image linking, thumb links, URL autolink)
*Smiley filter, word filter, etc should work with our extension

*/
class Forum extends Extension {
	public function onInitExt(InitExtEvent $event) {
		global $config, $database;

		// shortcut to latest

		if ($config->get_int("forum_version") < 1) {
			$database->create_table("forum_threads", "
					id SCORE_AIPK,
					sticky SCORE_BOOL NOT NULL DEFAULT SCORE_BOOL_N,
					title VARCHAR(255) NOT NULL,
					user_id INTEGER NOT NULL,
					date SCORE_DATETIME NOT NULL,
					uptodate SCORE_DATETIME NOT NULL,
					FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ON DELETE RESTRICT
					");
			$database->execute("CREATE INDEX forum_threads_date_idx ON forum_threads(date)", array());
			
			$database->create_table("forum_posts", "
					id SCORE_AIPK,
					thread_id INTEGER NOT NULL,
					user_id INTEGER NOT NULL,
					date SCORE_DATETIME NOT NULL,
					message TEXT,
					FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ON DELETE RESTRICT,
					FOREIGN KEY (thread_id) REFERENCES forum_threads (id) ON UPDATE CASCADE ON DELETE CASCADE
					");
			$database->execute("CREATE INDEX forum_posts_date_idx ON forum_posts(date)", array());

			$config->set_int("forum_version", 2);
			$config->set_int("forumTitleSubString", 25);
			$config->set_int("forumThreadsPerPage", 15);
			$config->set_int("forumPostsPerPage", 15);

			$config->set_int("forumMaxCharsPerPost", 512);

			log_info("forum", "extension installed");
		}
		if ($config->get_int("forum_version") < 2) {
			$database->execute("ALTER TABLE forum_threads ADD FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ON DELETE RESTRICT");
			$database->execute("ALTER TABLE forum_posts ADD FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ON DELETE RESTRICT");
			$config->set_int("forum_version", 2);
		}
	}
	
	public function onSetupBuilding(SetupBuildingEvent $event) {
		$sb = new SetupBlock("Forum");
		$sb->add_int_option("forumTitleSubString", "Title max long: ");
		$sb->add_int_option("forumThreadsPerPage", "<br>Threads per page: ");
		$sb->add_int_option("forumPostsPerPage", "<br>Posts per page: ");
		
		$sb->add_int_option("forumMaxCharsPerPost", "<br>Max chars per post: ");
		$event->panel->add_block($sb);
	}
	
	public function onUserPageBuilding(UserPageBuildingEvent $event) {
		global $database;
		
		$threads_count = $database->get_one("SELECT COUNT(*) FROM forum_threads WHERE user_id=?", array($event->display_user->id));
        $posts_count = $database->get_one("SELECT COUNT(*) FROM forum_posts WHERE user_id=?", array($event->display_user->id));
			
        $days_old = ((time() - strtotime($event->display_user->join_date)) / 86400) + 1;
				
        $threads_rate = sprintf("%.1f", ($threads_count / $days_old));
		$posts_rate = sprintf("%.1f", ($posts_count / $days_old));
				
		$event->add_stats("Forum threads: $threads_count, $threads_rate per day");
        $event->add_stats("Forum posts: $posts_count, $posts_rate per day");
	}


	public function onPageRequest(PageRequestEvent $event) {
		global $page, $user;

		if($event->page_matches("forum")) {
			switch($event->get_arg(0)) {
				case "index":
					$this->show_last_threads($page, $event, $user->is_admin());
					if(!$user->is_anonymous()) $this->theme->display_new_thread_composer($page);
					break;
				case "view":
					$threadID = int_escape($event->get_arg(1));
					$pageNumber = int_escape($event->get_arg(2));
					list($errors) = $this->sanity_check_viewed_thread($threadID);

					if($errors!=null)
					{
						$this->theme->display_error(500, "Error", $errors);
						break;
					}

					$this->show_posts($event, $user->is_admin());
					if($user->is_admin()) $this->theme->add_actions_block($page, $threadID);
					if(!$user->is_anonymous()) $this->theme->display_new_post_composer($page, $threadID);
					break;
				case "new":
					global $page;
					$this->theme->display_new_thread_composer($page);
					break;
				case "create":
					$redirectTo = "forum/index";
					if (!$user->is_anonymous())
					{
						list($errors) = $this->sanity_check_new_thread();

						if($errors!=null)
						{
							$this->theme->display_error(500, "Error", $errors);
							break;
						}

						$newThreadID = $this->save_new_thread($user);
						$this->save_new_post($newThreadID, $user);
						$redirectTo = "forum/view/".$newThreadID."/1";
					}

					$page->set_mode("redirect");
					$page->set_redirect(make_link($redirectTo));

					break;
				case "delete":
					$threadID = int_escape($event->get_arg(1));
					$postID = int_escape($event->get_arg(2));

					if ($user->is_admin()) {$this->delete_post($postID);}

					$page->set_mode("redirect");
					$page->set_redirect(make_link("forum/view/".$threadID));
					break;
				case "nuke":
					$threadID = int_escape($event->get_arg(1));

					if ($user->is_admin())
						$this->delete_thread($threadID);

					$page->set_mode("redirect");
					$page->set_redirect(make_link("forum/index"));
					break;
				case "answer":
					$threadID = int_escape($_POST["threadID"]);
					$total_pages = $this->get_total_pages_for_thread($threadID);
					if (!$user->is_anonymous())
					{
						list($errors) = $this->sanity_check_new_post();

						if ($errors!=null)
						{
							$this->theme->display_error(500, "Error", $errors);
							break;
						}
						$this->save_new_post($threadID, $user);
					}
					$page->set_mode("redirect");
					$page->set_redirect(make_link("forum/view/".$threadID."/".$total_pages));
					break;
				default:
					$page->set_mode("redirect");
					$page->set_redirect(make_link("forum/index"));
					//$this->theme->display_error(400, "Invalid action", "You should check forum/index.");
					break;
			}
		}
	}

	/**
	 * @param int $threadID
	 */
	private function get_total_pages_for_thread($threadID)
	{
		global $database, $config;
		$result = $database->get_row("SELECT COUNT(1) AS count FROM forum_posts WHERE thread_id = ?", array($threadID));

		return ceil($result["count"] / $config->get_int("forumPostsPerPage"));
	}

	private function sanity_check_new_thread()
	{
		$errors = null;
		if (!array_key_exists("title", $_POST))
		{
			$errors .= "<div id='error'>No title supplied.</div>";
		}
		else if (strlen($_POST["title"]) == 0)
		{
			$errors .= "<div id='error'>You cannot have an empty title.</div>";
		}
		else if (strlen(html_escape($_POST["title"])) > 255)
		{
			$errors .= "<div id='error'>Your title is too long.</div>";
		}

		if (!array_key_exists("message", $_POST))
		{
			$errors .= "<div id='error'>No message supplied.</div>";
		}
		else if (strlen($_POST["message"]) == 0)
		{
			$errors .= "<div id='error'>You cannot have an empty message.</div>";
		}

		return array($errors);
	}

	private function sanity_check_new_post()
	{
		$errors = null;
		if (!array_key_exists("threadID", $_POST))
		{
			$errors = "<div id='error'>No thread ID supplied.</div>";
		}
		else if (strlen($_POST["threadID"]) == 0)
		{
			$errors = "<div id='error'>No thread ID supplied.</div>";
		}
		else if (is_numeric($_POST["threadID"]))

			if (!array_key_exists("message", $_POST))
			{
				$errors .= "<div id='error'>No message supplied.</div>";
			}
			else if (strlen($_POST["message"]) == 0)
			{
				$errors .= "<div id='error'>You cannot have an empty message.</div>";
			}

		return array($errors);
	}

	/**
	 * @param int $threadID
	 */
	private function sanity_check_viewed_thread($threadID)
	{
		$errors = null;
		if (!$this->threadExists($threadID))
		{
			$errors = "<div id='error'>Inexistent thread.</div>";
		}            
		return array($errors);
	}

	/**
	 * @param int $threadID
	 */
	private function get_thread_title($threadID)
	{
		global $database;
		$result = $database->get_row("SELECT t.title FROM forum_threads AS t WHERE t.id = ? ", array($threadID));
		return $result["title"];
	}
		
	private function show_last_threads(Page $page, PageRequestEvent $event, $showAdminOptions = false)
	{
		global $config, $database;
		$pageNumber = $event->get_arg(1);
		$threadsPerPage = $config->get_int('forumThreadsPerPage', 15);
		$totalPages = ceil($database->get_one("SELECT COUNT(*) FROM forum_threads") / $threadsPerPage);

		if(is_null($pageNumber) || !is_numeric($pageNumber))
			$pageNumber = 0;
		else if ($pageNumber <= 0)
			$pageNumber = 0;
		else if ($pageNumber >= $totalPages)
			$pageNumber = $totalPages - 1;
		else
			$pageNumber--;

		$threads = $database->get_all(
				"SELECT f.id, f.sticky, f.title, f.date, f.uptodate, u.name AS user_name, u.email AS user_email, u.class AS user_class, sum(1) - 1 AS response_count ".
				"FROM forum_threads AS f ".
				"INNER JOIN users AS u ".
				"ON f.user_id = u.id ".
				"INNER JOIN forum_posts AS p ".
				"ON p.thread_id = f.id ".
				"GROUP BY f.id, f.sticky, f.title, f.date, u.name, u.email, u.class ".
				"ORDER BY f.sticky ASC, f.uptodate DESC LIMIT :limit OFFSET :offset"
				, array("limit"=>$threadsPerPage, "offset"=>$pageNumber * $threadsPerPage)
				);

		$this->theme->display_thread_list($page, $threads, $showAdminOptions, $pageNumber + 1, $totalPages);
	}

	private function show_posts(PageRequestEvent $event, $showAdminOptions = false)
	{
		global $config, $database;
		$threadID = $event->get_arg(1);
		$pageNumber = $event->get_arg(2);
		$postsPerPage = $config->get_int('forumPostsPerPage', 15);
		$totalPages = ceil($database->get_one("SELECT COUNT(*) FROM forum_posts WHERE thread_id = ?", array($threadID)) / $postsPerPage);
		$threadTitle = $this->get_thread_title($threadID);

		if(is_null($pageNumber) || !is_numeric($pageNumber))
			$pageNumber = 0;
		else if ($pageNumber <= 0)
			$pageNumber = 0;
		else if ($pageNumber >= $totalPages)
			$pageNumber = $totalPages - 1;
		else
			$pageNumber--;

		$posts = $database->get_all(
				"SELECT p.id, p.date, p.message, u.name as user_name, u.email AS user_email, u.class AS user_class ".
				"FROM forum_posts AS p ".
				"INNER JOIN users AS u ".
				"ON p.user_id = u.id ".
				"WHERE thread_id = :thread_id ".
				"ORDER BY p.date ASC ".
				"LIMIT :limit OFFSET :offset"
				, array("thread_id"=>$threadID, "offset"=>$pageNumber * $postsPerPage, "limit"=>$postsPerPage)
				);
		$this->theme->display_thread($posts, $showAdminOptions, $threadTitle, $threadID, $pageNumber + 1, $totalPages);
	}

	private function save_new_thread(User $user)
	{
		$title = html_escape($_POST["title"]);
		$sticky = !empty($_POST["sticky"]) ? html_escape($_POST["sticky"]) : "N";

		if($sticky == ""){
			$sticky = "N";
		}

		global $database;
		$database->execute("
				INSERT INTO forum_threads
				(title, sticky, user_id, date, uptodate)
				VALUES
				(?, ?, ?, now(), now())",
				array($title, $sticky, $user->id));

		$threadID = $database->get_last_insert_id("forum_threads_id_seq");

		log_info("forum", "Thread {$threadID} created by {$user->name}");

		return $threadID;
	}

	/**
	 * @param int $threadID
	 */
	private function save_new_post($threadID, User $user)
	{
		global $config;
		$userID = $user->id;
		$message = html_escape($_POST["message"]);

		$max_characters = $config->get_int('forumMaxCharsPerPost');
		$message = substr($message, 0, $max_characters);

		global $database;
		$database->execute("INSERT INTO forum_posts
				(thread_id, user_id, date, message)
				VALUES
				(?, ?, now(), ?)"
				, array($threadID, $userID, $message));

		$postID = $database->get_last_insert_id("forum_posts_id_seq");

		log_info("forum", "Post {$postID} created by {$user->name}");

		$database->execute("UPDATE forum_threads SET uptodate=now() WHERE id=?", array ($threadID));
	}

	/**
	 * @param int $threadID
	 * @param int $pageNumber
	 */
	private function retrieve_posts($threadID, $pageNumber)
	{
		global $database, $config;
		$postsPerPage = $config->get_int('forumPostsPerPage', 15);

		return $database->get_all(
				"SELECT p.id, p.date, p.message, u.name as user_name, u.email AS user_email, u.class AS user_class ".
				"FROM forum_posts AS p ".
				"INNER JOIN users AS u ".
				"ON p.user_id = u.id ".
				"WHERE thread_id = :thread_id ".
				"ORDER BY p.date ASC ".
				"LIMIT :limit OFFSET :offset "
				, array("thread_id"=>$threadID, "offset"=>($pageNumber - 1) * $postsPerPage, "limit"=>$postsPerPage));
	}

	/**
	 * @param int $threadID
	 */
	private function delete_thread($threadID)
	{
		global $database;
		$database->execute("DELETE FROM forum_threads WHERE id = ?", array($threadID));
		$database->execute("DELETE FROM forum_posts WHERE thread_id = ?", array($threadID));
	}

	/**
	 * @param int $postID
	 */
	private function delete_post($postID)
	{
		global $database;
		$database->execute("DELETE FROM forum_posts WHERE id = ?", array($postID));
	}

	/**
	 * @param int $threadID
	 */
	private function threadExists($threadID)
	{
		global $database;
		$result=$database->get_one("SELECT EXISTS (SELECT * FROM forum_threads WHERE id= ?)", array($threadID));
		if ($result==1){
			return true;
		}else{
			return false;
		}
	}
}