<?php

require_once(__DIR__."/libfilelist2zip.php");

function make_attachment($thash) {
    global $proj;

    $pf=realpath(__DIR__."/../".$proj["path"]."/automake_attachment.php");

    if(!is_readable($pf)) {
        gen_error_500("challange ".$proj["name"]." has been found, but the entry automake_attachment.php does not exist.");
        exit;
    }

    require($pf);

    if(!function_exists("make_attachment_impl")) {
        gen_error_500("challange ".$proj["name"]." has been found, but the entry automake_attachment.php doesn't implement the function make_attachment_impl(\$team_hash).");
        exit;
    }

    $font_path=getenv("GDFONTPATH");

    if($font_path===false) {
        $font_path="";
    } else {
        $font_path.=";";
    }

    //init GDFONTPATH to generate images containing text

    //$font_path.=realpath(__DIR__).";";
    //$font_path.=realpath(__DIR__."/../").";";
    $font_path.=realpath(__DIR__."/../assets/");//.";";
    //$font_path.=dirname($pf).";";

    putenv("GDFONTPATH=".$font_path);

    //echo getenv("GDFONTPATH");

    $GLOBALS["c_random_int_seed"]=hash("sha512", hash("md5", hash("sha256", $thash, true)), true);

    $GLOBALS["c_random_int"]=function($min, $max) {
        if(!is_int($min) || !is_int($max)) {
            gen_error_500("\$c_random_int(): invalid arguments: \$min or \$max is not integer");
            exit;
        }
        if($min==$max) {
            return $min;
        }
        if($min>$max) {
            list($min, $max)=[$max, $min];
        }
        $delta=$max-$min;
        if($delta<0||$delta>PHP_INT_MAX) {
            gen_error_500("\$c_random_int(): \$delta is not between 0 and PHP_INT_MAX(".(string)PHP_INT_MAX.")");
            exit;
        }
        $t=$delta;
        $res=0;
        for($a=0; $t>0; $a++) {
            $res<<=8;
            $res|=unpack("C", $GLOBALS["c_random_int_seed"][$a&63])[1]; //&63 is equal to %64
            $t>>=8;
        }
        unset($a);
        $res&=$delta; //avoid mod(%) operator, as it makes the result not evenly distributed
        $GLOBALS["c_random_int_seed"]=hash("sha512", $GLOBALS["c_random_int_seed"], true);
        return $min+$res;
    };

    //the function make_attachment_impl($team_hash) should return an array [(string)filename, (string)file_content] on success, or boolean false if it failed to generate.

    $fn=make_attachment_impl($thash);
    if($fn===false||!is_array($fn)||count($fn)!=2||gettype($fn[0])!="string"||gettype($fn[1])!="string") {
        $out="failed to make attachment for challange ".$proj["name"].": function call to make_attachment_impl(\$team_hash) failed or the returned value is invalid.";
        if(gettype($fn)=="string") {
            $out.="\nThe generator returned the following error:\n";
            $out.=$fn;
        }
        gen_error_500($out);
        exit;
    }
    if(strlen($fn[0])<=0) {
        $fn[0]="attachment.bin";
    }
    return $fn;
}