<?php
    /**
     * Uguu
     *
     * @copyright Copyright (c) 2022 Go Johansson (nokonoko) <neku@pomf.se>
     *
     * This program is free software: you can redistribute it and/or modify
     * it under the terms of the GNU General Public License as published by
     * the Free Software Foundation, either version 3 of the License, or
     * (at your option) any later version.
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program.  If not, see <https://www.gnu.org/licenses/>.
     */
    
    namespace Pomf\Uguu\Classes;
    
    use Exception;
    use PDO;
    
    class Database
    {
        private PDO $DB;
        
        /**
         * Sets the value of the DB variable.
         *
         * @param $DB PDO The database connection.
         */
        public function setDB(PDO $DB):void
        {
            $this->DB = $DB;
        }
        
        /**
         * Checks if a file name exists in the database
         *
         * @param $name string The name of the file.
         *
         * @return int The number of rows that match the query.
         * @throws \Exception
         */
        public function dbCheckNameExists(string $name):int
        {
            try {
                $q = $this->DB->prepare('SELECT COUNT(filename) FROM files WHERE filename = (:name)');
                $q->bindValue(':name', $name);
                $q->execute();
                return $q->fetchColumn();
            }
            catch (Exception) {
                throw new Exception('Cant check if name exists in DB.', 500);
            }
        }
        
        /**
         * Checks if the file is blacklisted
         *
         * @param $FILE_INFO array An array containing the following:
         *
         * @throws \Exception
         */
        public function checkFileBlacklist(array $FILE_INFO):void
        {
            try {
                $q = $this->DB->prepare('SELECT hash, COUNT(*) AS count FROM blacklist WHERE hash = (:hash)');
                $q->bindValue(':hash', $FILE_INFO['SHA1']);
                $q->execute();
                $result = $q->fetch();
                if ($result['count'] > 0) {
                    throw new Exception('File blacklisted!', 415);
                }
            }
            catch (Exception) {
                throw new Exception('Cant check blacklist DB.', 500);
            }
        }
        
        /**
         * Checks if the file already exists in the database
         *
         * @param $hash string The hash of the file you want to check for.
         *
         * @throws \Exception
         */
        public function antiDupe(string $hash):bool|array|string
        {
            if (!$this->CONFIG['ANTI_DUPE']) {
                return true;
            }
            try {
                $q = $this->DB->prepare(
                   'SELECT filename, COUNT(*) AS count FROM files WHERE hash = (:hash)',
                );
                $q->bindValue(':hash', $hash);
                $q->execute();
                $result = $q->fetch();
                if ($result['count'] > 0) {
                    return $result['filename'];
                } else {
                    return true;
                }
            }
            catch (Exception) {
                throw new Exception('Cant check for dupes in DB.', 500);
            }
        }
        
        /**
         * Inserts a new file into the database
         *
         * @param $FILE_INFO       array
         * @param $fingerPrintInfo array
         *
         * @throws \Exception
         */
        public function newIntoDB(array $FILE_INFO, array $fingerPrintInfo):void
        {
            try {
                $q = $this->DB->prepare(
                   'INSERT INTO files (hash, originalname, filename, size, date, ip)' .
                   'VALUES (:hash, :orig, :name, :size, :date, :ip)',
                );
                $q->bindValue(':hash', $FILE_INFO['SHA1']);
                $q->bindValue(':orig', $FILE_INFO['NAME']);
                $q->bindValue(':name', $FILE_INFO['NEW_NAME']);
                $q->bindValue(':size', $FILE_INFO['SIZE'], PDO::PARAM_INT);
                $q->bindValue(':date', $fingerPrintInfo['timestamp']);
                $q->bindValue(':ip', $fingerPrintInfo['ip']);
                $q->execute();
            }
            catch (Exception) {
                throw new Exception('Cant insert into DB.', 500);
            }
        }
        
        /**
         * Creates a new row in the database with the information provided
         *
         * @param $fingerPrintInfo array
         */
        public function createRateLimit(array $fingerPrintInfo):void
        {
            $q = $this->DB->prepare(
               'INSERT INTO timestamp (iphash, files, time)' .
               'VALUES (:iphash, :files, :time)',
            );
            $q->bindValue(':iphash', $fingerPrintInfo['ip_hash']);
            $q->bindValue(':files', $fingerPrintInfo['files_amount']);
            $q->bindValue(':time', $fingerPrintInfo['timestamp']);
            $q->execute();
        }
        
        /**
         * Update the rate limit table with the new file count and timestamp
         *
         * @param $fCount          int The number of files uploaded by the user.
         * @param $iStamp          boolean A boolean value that determines whether or not to update the timestamp.
         * @param $fingerPrintInfo array An array containing the following keys:
         */
        public function updateRateLimit(int $fCount, bool $iStamp, array $fingerPrintInfo):void
        {
            if ($iStamp) {
                $q = $this->DB->prepare(
                   'UPDATE ratelimit SET files = (:files), time = (:time) WHERE iphash = (:iphash)',
                );
                $q->bindValue(':time', $fingerPrintInfo['timestamp']);
            } else {
                $q = $this->DB->prepare(
                   'UPDATE ratelimit SET files = (:files) WHERE iphash = (:iphash)',
                );
            }
            $q->bindValue(':files', $fCount);
            $q->bindValue(':iphash', $fingerPrintInfo['ip_hash']);
            $q->execute();
        }
        
        /**
         * Checks if the user has uploaded more than 100 files in the last minute, if so it returns true, if not it updates the database with the new file
         * count and timestamp
         *
         * @param $fingerPrintInfo array An array containing the following:
         *
         * @return bool A boolean value.
         */
        public function checkRateLimit(array $fingerPrintInfo):bool
        {
            $q = $this->DB->prepare(
               'SELECT files, time, iphash, COUNT(*) AS count FROM ratelimit WHERE iphash = (:iphash)',
            );
            $q->bindValue(':iphash', $fingerPrintInfo['ip_hash']);
            $q->execute();
            $result = $q->fetch();
            $nTime = $fingerPrintInfo['timestamp'] - (60);
            switch (true) {
                //If more then 100 files trigger rate-limit
                case $result['files'] > 100:
                    return true;
                //if timestamp is older than one minute, set new files count and timestamp
                case $result['time'] < $nTime:
                    $this->updateRateLimit($fingerPrintInfo['files_amount'], true, $fingerPrintInfo);
                    break;
                //if timestamp isn't older than one-minute update the files count
                case $result['time'] > $nTime:
                    $this->updateRateLimit($fingerPrintInfo['files_amount'] + $result['files'], false, $fingerPrintInfo);
                    break;
                //If there is no other match a record does not exist, create one
                default:
                    $this->createRateLimit($fingerPrintInfo);
                    break;
            }
            return false;
        }
    }