<?php

/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 43):
 * Chris Stretton wrote this file. As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.
 * ----------------------------------------------------------------------------
 */

    Class GWTemplate {

        private $bin = "";
        private $attribcount = 0;
        private $attribsize = 0;
        private $b64 = array("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/");

        public $attribs = array();
        public $skills = array();
        public $primary = 0;
        public $secondary = 0;
        public $code = "";

        public function __construct($code = "AAAAAAAAAAAAAAA") {
            $this->code = $code;
            $this->load();
        }

        public function parse() { // Legacy function
            $this->load();
        }

        public function load() {
            if ($this->code == "") {
                throw new Exception('No code set');
            }
            $this->bin = $this->b642binstr();
            if (strlen($this->bin) < 90) {
                throw new Exception('Invalid code');
            }
            $this->primary = $this->binstr2int(substr($this->bin, 6, 4));
            $this->secondary = $this->binstr2int(substr($this->bin, 10, 4));
            $this->attribcount = $this->binstr2int(substr($this->bin, 14, 4));
            $this->attribsize = 4 + $this->binstr2int(substr($this->bin, 18, 4));
            $pos = 22;
            for($i = 0; $i < $this->attribcount; $i ++, $pos += ($this->attribsize + 4)) {
                $this->attribs[$i]['attribute'] = $this->binstr2int(substr($this->bin, $pos, $this->attribsize));
                $this->attribs[$i]['value'] = $this->binstr2int(substr($this->bin, $pos + $this->attribsize, 4));
            }
            $this->skillsize = 8 + $this->binstr2int(substr($this->bin, $pos, 4));
            $pos += 4;
            for($i = 0; $i < 8; $i ++, $pos += $this->skillsize) {
                $this->skills[$i] = $this->binstr2int(substr($this->bin, $pos, $this->skillsize));
            }
        }

        public function save() {
            if (count($this->skills) < 8) {
                throw new Exception('A build requires 8 skills.');
            }
            $binary = "000000";
            $binary .= $this->int2binstr($this->primary);
            $binary .= $this->int2binstr($this->secondary);
            $binary .= $this->int2binstr(count($this->attribs));
            $size = 0;
            $b2 = "";
            foreach ($this->attribs as $attrib) {
                $b = strlen($this->int2binstr($attrib['attribute']));
                if ($b > $size) {
                    $size = $b;
                }
            }
            foreach ($this->attribs as $attrib) {
                $b2 .= $this->int2binstr($attrib['attribute'], $size);
                $b2 .= $this->int2binstr($attrib['value']);
            }
            $binary .= $this->int2binstr($size - 4);
            $binary .= $b2;
            $size = 0;
            $b2 = "";
            foreach ($this->skills as $skill) {
                $b = strlen($this->int2binstr($skill, $size));
                if ($b > $size) {
                    $size = $b;
                }
            }
            foreach ($this->skills as $skill) {
                $b2 .= $this->int2binstr($skill, $size);
            }
            $binary .= $this->int2binstr($size - 8);
            $binary .= $b2;
            $this->bin = $binary;
            $this->code = $this->binstr2b64();
        }

        private function binstr2b64() {
            $binary = $this->bin;
            $c = strlen($binary);
            $string = "";
            for ($i = 0; $i < $c; $i += 6) {
                $string .= $this->b64[$this->binstr2int(substr($binary, $i, 6))];
            }
            return $string;
        }

        private function b642binstr() {
            $string = $this->code;
            $b64 = array_flip($this->b64);
            $c = strlen($string);
            $binary = "";
            for ($i = 0; $i < $c; $i ++) {
                $binary .= $this->int2binstr($b64[$string{$i}], 6);
            }
            return $binary;
        }

        private function int2binstr($int, $padding = 4) {
            return strrev(str_pad(decbin($int), $padding, "0", STR_PAD_LEFT));
        }

        private function binstr2int($binary) {
            $c = strlen($binary);
            $value = 0;
            for ($i = 0; $i < $c; $i ++) {
                $value += $binary{$i} * pow(2, $i);
            }
            return $value;
        }
    }

?>