WeChat에서 개발한 버스 환승 기능 코드에 대한 자세한 설명

/*
     aibang's api return josn data
     
     d_eng (sh109419@163.com)
     2013-12-4
 */
 
define("APP_KEY", "xx00ac396d6d75e8681fc8380060c5b2");
include_once "ABClient.php";
 
//header("Content-Type:text/html; charset=utf-8"); 
 
function bustransfer($city,$start,$end) {
    $client = new ABClient(APP_KEY);
    list($code, $arr) = $client->getBusTransfer($city, array("start_addr" =>$start, "end_addr"=>$end));
    if ($code<>200){
        return false;
    }
     
    $ret ="";
    $buses = $arr[buses][bus];
    // show the top 3 records
    $ret = $start ."-->".$end."\n";
    $count = 1;
    foreach ($buses as $bus) {
        if ($count > 3) break;
 
        $segments =$bus[segments][segment];
         $ret .= "<方案".$count++.">\n";
        // get line name and remove remark
        $linename = "";
        foreach($segments as $segment) {
            if (!empty($linename)) $linename .= &#39;--&#39; ;
            $linename  .= shortlinename($segment[line_name]);
        }
        $ret .= $linename . "\n" ;
        $total = sprintf("%d分钟 %d米 步行%d米",$bus[time],$bus[dist],$bus[foot_dist]);
        $ret .= $total . "\n" ;
        // detail
        $from = sprintf("从 %s ",$start);
        $ret .= $from;
        foreach($segments as $segment) {
            if ($segment[foot_dist] > 0) {
                $segfoot = sprintf("步行%d米 到达 %s",$segment[foot_dist],$segment[start_stat]);
                $ret .= $segfoot . "\n" ;
            }
            $stats = substr_count($segment[stats],&#39;;&#39;);
            $line = sprintf("乘坐 %s(%d站) 到达 %s",shortlinename($segment[line_name]),$stats,$segment[end_stat]);
            $ret .= $line . "\n" ;
        }
        if ($bus[last_foot_dist] > 0) {
            $lastfoot = sprintf("步行%d米 到达 %s",$bus[last_foot_dist],$end);
            $ret .= $lastfoot;
        }
    }
    return $ret;
}
 
function shortlinename($linename){
    return substr($linename,0,strpos($linename,&#39;(&#39;));
}
 
$a=bustransfer("南昌","老福山","青山路口");
var_dump($a);