<?php

class AuthUserFile
{
    private $filename;
    private $lines = array();
    private $write = false;

    public function __construct( $filename )
    {
        if( !empty( $filename ) )
        {
            $this->filename = $filename;

            if( file_exists( $filename ) )
            {
                $this->lines = file( $filename );
            }
            
        }
        else
        {
            throw new Exception( "filename is empty" );
        }
    }

    public function addUser( $username, $password )
    {
        if( !empty( $username ) )
        {
            if( $this->getIndex( $username ) == -1 )
            {
                $line[0] = $username;
                $line[1] = password_hash( $password, PASSWORD_BCRYPT );
                $nl = chr(13) . chr(10); // new line
                $this->lines[] = implode( ":", $line ) . $nl;
                $this->write = true;
                return true;
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }

    public function delUser($username ) {

        $index = $this->getIndex( $username ); // get index from username

        if( $index > -1 ) { // found username

            unset( $this->lines[$index] ); // delete entry from array
            $this->write = true;
            return true;
        }
        else
            return false;
    }

    public function __destruct() {

        if( $this->write ) {

            if( count( $this->lines ) > 0 ) {

                $fp = fopen( $this->filename, "w" );

                foreach( $this->lines as $line )
                    fputs( $fp, $line );

                fclose( $fp );
            }
        }
    }

    private function getIndex( $username ) {

        if( count( $this->lines ) > 0 ) {

            foreach( $this->lines as $index=>$line ) {

                $data = explode( ":", $line );

                if( $data[0] == $username )
                    return $index;
            }
        }

        return -1; // username not found
    }
}