php 积分抽奖活动（大转盘）

以下是项目代码(公众号，使用积分进行抽奖活动)，只可做参考：

public function Sncode()
{
    $tid = I(\'request.tid\', 0, \'intval\');  // 大转盘id,
    $wid = I(\'request.wid\', 0, \'intval\');  // 应用id,可去掉
    $token = $this->getOpenId();　　　　　　 // 获取微信用户的token

    // 定义数据库
    $big_wheel = D(\'Big_wheel\');   // 大转盘设置表
    $big_wheel_log = M(\'big_wheel_log\');  // 抽奖记录表
    $big_code = M(\'big_wheel_code\');    // 已抽中奖品记录表

    // 查询抽奖活动数据
    $where = " `id` = " . $tid;
    $list = $big_wheel->relation(true)->where($where)->find();

    // 查询积分，若积分不足则无法参与抽奖
    $score = $this->duser[\'score\'];
    if ($score < $list[\'score_num\']) {
        echo json_encode(array(\'error\' => \'score\'));
        exit;
    }

    //已抽奖总次数
    $where_log = "`big_wheel_id`=" . $tid . " and `w_id`=" . $list[\'w_id\'] . "  and `code`=\'" . $token . "\'";
    $count = $big_wheel_log->where($where_log)->count();

    //减去额外获得的抽奖机会 - 分享（此操作暂时隐藏）
    $map_share[\'wid\'] = array(\'eq\', $wid);
    $map_share[\'token\'] = array(\'eq\', $token);
    $map_share[\'big_wheel_id\'] = array(\'eq\', $tid);
    $count_share = M(\'big_wheel_share\')->where($map_share)->count();
    $count = $count - $count_share;


    //当日限制次数
    if ($list[\'most_num_times\'] > 0) {
        $where_log .= " and (addtime BETWEEN " . strtotime(date(\'Y-m-d 00:00:00\')) . " and " . strtotime(date(\'Y-m-d 23:59:59\')) . ")";
        $count_today = $big_wheel_log->where($where_log)->count();
        $count_today = $count_today - $count_share;//  当日抽奖次数减去额外获得的抽奖次数

    }

    //判断抽奖次数
    if ($count_today >= $list[\'most_num_times\'] && $list[\'most_num_times\'] > 0) {
        echo json_encode(array(\'error\' => \'invalid_today\', \'nums\' => $list[\'most_num_times\']));
        exit;
    }

    // 扣除积分
    M(\'app_dishop_duser\')->where(array(\'id\' => $this->duser[\'id\']))->setDec(\'score\', $list[\'score_num\']);

    //插入抽奖记录表
    $data[\'big_wheel_id\'] = $tid;
    $data[\'w_id\'] = $list[\'w_id\'];
    $data[\'code\'] = $token;
    $data[\'date\'] = date(\'Y-m-d\', time());
    $data[\'addtime\'] = time();
    $big_wheel_log->add($data);

    /*
     * 奖项数组
     * 是一个二维数组，记录了所有本次抽奖的奖项信息，
     * 其中id表示中奖等级，prize表示奖品，v表示中奖概率。
     * 注意其中的v必须为整数，你可以将对应的 奖项的v设置成0，即意味着该奖项抽中的几率是0，
     * 数组中v的总和（基数），基数越大越能体现概率的准确性。
     * 本例中v的总和为100，那么中奖概率就是1%，
     * 如果v的总和是10000，那中奖概率就是万分之一了。
     *
     */
    $prize_arr = array(
        \'0\' => array(\'id\' => 1, \'prize\' => \'1\', \'v\' => $list[\'c_probability_one\']),
        \'1\' => array(\'id\' => 2, \'prize\' => \'谢谢参与\', \'v\' => $list[\'no_probability\']),
        \'2\' => array(\'id\' => 3, \'prize\' => \'2\', \'v\' => $list[\'c_probability_two\']),
        \'3\' => array(\'id\' => 4, \'prize\' => \'3\', \'v\' => $list[\'c_probability_three\']),
    );

    foreach ($prize_arr as $key => $val) {
        $arr[$val[\'id\']] = $val[\'v\'];
    }

    $rid = $this->get_rand($arr); //根据概率获取奖项id

    $res[\'yes\'] = $prize_arr[$rid - 1][\'prize\']; //中奖项
    unset($prize_arr[$rid - 1]); //将中奖项从数组中剔除，剩下未中奖项
    shuffle($prize_arr); //打乱数组顺序
    for ($i = 0; $i < count($prize_arr); $i++) {
        $pr[] = $prize_arr[$i][\'prize\'];
    }

    // 若抽中奖品，则存入库中，并返回提示
    if ($res[\'yes\'] == \'1\' || $res[\'yes\'] == \'2\' || $res[\'yes\'] == \'3\') {
        //这个是保存到数据库表示你这个人抽中奖品
        if ($res[\'yes\'] == \'1\') {
            // 查询这是第几次抽中此奖品，若抽中次数大于奖品数，则此次抽中的奖品作废
            $code_count = $big_code->where(array(\'prizetype\' => 1, \'big_wheel_id\' => $tid))->count();
            if ($code_count >= $list[\'c_num_one\']) {
                $data = array(\'prizetype\' => null, \'success\' => true);
                echo json_encode($data);
                exit;
            }
            $code[\'category\'] = $list[\'c_name_one\'];
        } elseif ($res[\'yes\'] == \'2\') {
            // 查询这是第几次抽中此奖品，若抽中次数大于奖品数，则此次抽中的奖品作废
            $code_count = $big_code->where(array(\'prizetype\' => 2, \'big_wheel_id\' => $tid))->count();
            if ($code_count >= $list[\'c_num_two\']) {
                $data = array(\'prizetype\' => null, \'success\' => true);
                echo json_encode($data);
                exit;
            }
            $code[\'category\'] = $list[\'c_name_two\'];
        } elseif ($res[\'yes\'] == \'3\') {
            // 查询这是第几次抽中此奖品，若抽中次数大于奖品数，则此次抽中的奖品作废
            $code_count = $big_code->where(array(\'prizetype\' => 3, \'big_wheel_id\' => $tid))->count();
            if ($code_count >= $list[\'c_num_three\']) {
                $data = array(\'prizetype\' => null, \'success\' => true);
                echo json_encode($data);
                exit;
            }
            $code[\'category\'] = $list[\'c_name_three\'];
        }
        $code[\'sn_id\'] = \'sn\' . time() . mt_rand(10000, 99999);
        $code[\'w_id\'] = $list[\'w_id\'];
        $code[\'big_wheel_id\'] = $tid;
        $code[\'prizetype\'] = $res[\'yes\'];
        $code[\'code\'] = $token;
        $code[\'winners_time\'] = time();
        $code[\'state\'] = 1;
        $big_code->add($code);
        $data = array(\'sn\' => $code[\'sn_id\'], \'prizetype\' => $res[\'yes\'], \'success\' => true);
        echo json_encode($data);
        exit;
    } else {
        $data = array(\'prizetype\' => null, \'success\' => true);
        echo json_encode($data);
        exit;
    }
}

// 抽奖概率计算
public function get_rand($proArr)
{
    $result = \'\';

    //概率数组的总概率精度
    $proSum = array_sum($proArr);

    //概率数组循环
    foreach ($proArr as $key => $proCur) {
        $randNum = mt_rand(1, $proSum);
        if ($randNum <= $proCur) {
            $result = $key;
            break;
        } else {
            $proSum -= $proCur;
        }
    }
    unset ($proArr);
    return $result;
}