using Attribute;
using Dto;
using Vo;
using Model;
using Service;
using System.Text;
using System.Security.Cryptography;
using Aliyun.OSS;
using Infrastructure;

namespace Services.Base
{
    /// <summary>
    /// app底部导航Service业务层处理
    /// </summary>
    [AppService(ServiceType = typeof(IOssService), ServiceLifetime = LifeTime.Transient)]
    public class OssService : IOssService
    {
        /// <summary>
        /// 前端上传oss返回参数
        /// </summary>
        /// <param name="parm">请求参数</param>
        /// <returns>前端上传oss返回参数</returns>
        public OssUploadVo uploadInfo(OssUploadDto param)
        {
            string dir = param.dir; //文件上传路径
            var options = App.OptionsSetting;
            var oss = options.ossConfigs;
            var OssUrl = oss.Host;
            var AccessKeyId = oss.Key;
            var AccessKeySecret = oss.Secret;
            var endpoint = "https://" + oss.Endpoint;

            // 构造OssClient实例。 endpoint 格式:https://oss-cn-beijing.aliyuncs.com
            var ossClient = new OssClient(endpoint, AccessKeyId, AccessKeySecret);
            var config = new PolicyConditions();
            config.AddConditionItem(PolicyConditions.CondContentLengthRange, 1, 1024L * 1024 * 1024 * 5);// 文件大小范围：单位byte
            config.AddConditionItem(MatchMode.StartWith, PolicyConditions.CondKey, dir);
            var expire = DateTimeOffset.Now.AddMinutes(30);// 过期时间

            // 生成 Policy，并进行 Base64 编码
            var policy = ossClient.GeneratePostPolicy(expire.LocalDateTime, config);
            var policyBase64 = Convert.ToBase64String(Encoding.UTF8.GetBytes(policy));

            // 计算签名
            var hmac = new HMACSHA1(Encoding.UTF8.GetBytes(AccessKeySecret));
            var bytes = hmac.ComputeHash(Encoding.UTF8.GetBytes(policyBase64));
            var Signature = Convert.ToBase64String(bytes);

            var response = new OssUploadVo()
            {
                ossUrl = OssUrl,
                accessKeyId = AccessKeyId,
                policy = policyBase64,
                expiration = expire,
                signature = Signature,
                dir = dir,
            };
            return response;
        }
    }
}