<?php
/*
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)", []);

            $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)", []);

            $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 = $database->get_one("SELECT COUNT(*) FROM forum_threads WHERE user_id=?", [$event->display_user->id]);
        $posts_count = $database->get_one("SELECT COUNT(*) FROM forum_posts WHERE user_id=?", [$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(PageMode::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(PageMode::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(PageMode::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(PageMode::REDIRECT);
                    $page->set_redirect(make_link("forum/view/".$threadID."/".$total_pages));
                    break;
                default:
                    $page->set_mode(PageMode::REDIRECT);
                    $page->set_redirect(make_link("forum/index"));
                    //$this->theme->display_error(400, "Invalid action", "You should check forum/index.");
                    break;
            }
        }
    }

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

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

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

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

        return [$errors];
    }

    private function sanity_check_new_post()
    {
        $errors = null;
        if (!array_key_exists("threadID", $_POST)) {
            $errors = "<div id='error'>No thread ID supplied.</div>";
        } elseif (strlen($_POST["threadID"]) == 0) {
            $errors = "<div id='error'>No thread ID supplied.</div>";
        } elseif (is_numeric($_POST["threadID"])) {
            if (!array_key_exists("message", $_POST)) {
                $errors .= "<div id='error'>No message supplied.</div>";
            } elseif (strlen($_POST["message"]) == 0) {
                $errors .= "<div id='error'>You cannot have an empty message.</div>";
            }
        }

        return [$errors];
    }

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

    private function get_thread_title(int $threadID)
    {
        global $database;
        $result = $database->get_row("SELECT t.title FROM forum_threads AS t WHERE t.id = ? ", [$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)) {
            $pageNumber = 0;
        } elseif ($pageNumber <= 0) {
            $pageNumber = 0;
        } elseif ($pageNumber >= $totalPages) {
            $pageNumber = $totalPages - 1;
        } else {
            $pageNumber--;
        }

        $threads = $database->get_all(
            "SELECT f.id, f.sticky, f.title, f.date, f.uptodate, u.name AS user_name, u.email AS user_email, u.class AS user_class, sum(1) - 1 AS response_count ".
                "FROM forum_threads AS f ".
                "INNER JOIN users AS u ".
                "ON f.user_id = u.id ".
                "INNER JOIN forum_posts AS p ".
                "ON p.thread_id = f.id ".
                "GROUP BY f.id, f.sticky, f.title, f.date, u.name, u.email, u.class ".
                "ORDER BY f.sticky ASC, f.uptodate DESC LIMIT :limit OFFSET :offset",
            ["limit"=>$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 = ?", [$threadID]) / $postsPerPage);
        $threadTitle = $this->get_thread_title($threadID);

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

        $posts = $database->get_all(
            "SELECT p.id, p.date, p.message, u.name as user_name, u.email AS user_email, u.class AS user_class ".
                "FROM forum_posts AS p ".
                "INNER JOIN users AS u ".
                "ON p.user_id = u.id ".
                "WHERE thread_id = :thread_id ".
                "ORDER BY p.date ASC ".
                "LIMIT :limit OFFSET :offset",
            ["thread_id"=>$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;
        $database->execute(
            "
				INSERT INTO forum_threads
				(title, sticky, user_id, date, uptodate)
				VALUES
				(?, ?, ?, now(), now())",
            [$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;
    }

    private function save_new_post(int $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;
        $database->execute("INSERT INTO forum_posts
				(thread_id, user_id, date, message)
				VALUES
				(?, ?, now(), ?)", [$threadID, $userID, $message]);

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

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

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

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

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

    private function delete_thread(int $threadID)
    {
        global $database;
        $database->execute("DELETE FROM forum_threads WHERE id = ?", [$threadID]);
        $database->execute("DELETE FROM forum_posts WHERE thread_id = ?", [$threadID]);
    }

    private function delete_post(int $postID)
    {
        global $database;
        $database->execute("DELETE FROM forum_posts WHERE id = ?", [$postID]);
    }

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