<?php
namespace app\common\library;

use think\Cache;
use think\Hook;

/**
 * 根据汇率转换金额
 * Class CoinRate
 * @package app\common\library
 */
class CoinRate
{
    protected static $apiUrl = 'https://api.it120.cc/gooking/forex/rate?fromCode=%s&toCode=%s';

    /**
     * 转换汇率金额
     * @param $amount
     * @param string $from
     * @param string $to
     * @return float|mixed
     */
    public static function transfer($amount, $from='CNY', $to='USD')
    {
        if(empty($from) || empty($to)){
            return $amount;
        }

        $cacheKey = "cache:rates:{$from}_{$to}";
        $data = Cache::get($cacheKey);
        $rate = isset($data['rate'])? floatval($data['rate']) : 0.00;
        $expired = isset($data['expired'])? intval($data['expired']) : 0;
        if($rate<=0 || $expired<time()){
            $result = curl_api_get(sprintf(self::$apiUrl, $to, $from));
            $result = $result? json_decode($result, true) : [];
            $data = isset($result['data'])? $result['data'] : [];
            $rate = isset($data['rate'])? floatval($data['rate']) : 0.00;
            if($rate > 0){
                $data['expired'] = time() + 300;
                Cache::set($cacheKey, $data, time() + 300);
            }
        }

        return $rate>0? floatval($rate * $amount) : $amount;
    }

    /**
     * 转换汇率金额
     * @param $amount
     * @param string $from
     * @param string $to
     * @return float|mixed
     */
    public static function getRate($from='CNY', $to='USD')
    {
        $cacheKey = "cache:rates:{$from}_{$to}";
        $data = Cache::get($cacheKey);
        $rate = isset($data['rate'])? floatval($data['rate']) : 0.00;
        $expired = isset($data['expired'])? intval($data['expired']) : 0;
        if($rate<=0 || $expired<time()){
            $result = curl_api_get(sprintf(self::$apiUrl, $to, $from));
            $result = $result? json_decode($result, true) : [];
            $data = isset($result['data'])? $result['data'] : [];
            $rate = isset($data['rate'])? floatval($data['rate']) : 0.00;
            if($rate > 0){
                $data['expired'] = time() + 300;
                Cache::set($cacheKey, $data, time() + 300);
            }
        }

        return $rate;
    }
}
?>