<?php 

// TODO: add logging to file

class Logger {
    private static $instance;
    private $loglevel = 1;

    public static function singleton() {
        if ( ! is_object(self::$instance ) ) {
            self::$instance = new Logger();
        }
    }

    private function level2int ($lvl) {
        if ( is_numeric($lvl) ) return $lvl;
        if ( $lvl == 'INFO' ) return 3;
        if ( $lvl == 'ERROR' ) return 1;
        if ( $lvl == 'DEBUG' ) return 5;
        if ( $lvl == 'WARNING' ) return 2;
        if ( $lvl == 'VERBOSE' ) return 4;
        if ( $lvl == 'FATAL' ) return 0;
        return 5;
    }

    private function level2string ($lvl) {
        if ( is_string($lvl) ) return $lvl;
        if ( $lvl == 3 ) return 'INFO';
        if ( $lvl == 1 ) return 'ERROR';
        if ( $lvl == 5 ) return 'DEBUG';
        if ( $lvl == 2 ) return 'WARNING';
        if ( $lvl == 4 ) return 'VERBOSE';
        if ( $lvl == 0 ) return 'FATAL';
        return 'DEBUG';
    }
    
    public function setLogLevel ($level) {
        self::singleton();
        self::$instance->loglevel = self::$instance->level2int($level);
    }

    private function Log ($level,&$a) {
        $a[0] = self::$instance->level2string($level) . ': ' . $a[0] . PHP_EOL;
        call_user_func_array('printf',$a);
    }

    public function Debug ($msg) {
        self::singleton();
        if ( self::$instance->loglevel < 5 ) return 0;
        self::$instance->Log(5,func_get_args()); 
    }

    public function Verbose ($msg) {
        self::singleton();
        if ( self::$instance->loglevel < 4 ) return 0;
        self::$instance->Log(4,func_get_args()); 
    }

    public function Info ($msg) {
        self::singleton();
        if ( self::$instance->loglevel < 3 ) return 0;
        self::$instance->Log(3,func_get_args()); 
    }

    public function Warning ($msg) {
        self::singleton();
        if ( self::$instance->loglevel < 2 ) return 0;
        self::$instance->Log(2,func_get_args()); 
    }

    public function Error ($msg) {
        self::singleton();
        if ( self::$instance->loglevel < 1 ) return 0;
        self::$instance->Log(1,func_get_args()); 
    }

    public function Fatal ($msg) {
        self::singleton();
        self::$instance->Log(0,func_get_args()); 
        exit(1);
    }
}

?>