using Aliyun.OSS;
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace Tools.AliYun
{
    public class OSS
    {
        private string accessKeyId;
        private string accessKeySecret;
        private string bucket;
        private string endpoint;
        private string host;


        /// <summary>
        /// 初始化OSS对象
        /// </summary>
        /// <param name="accessKeyId">key : CRGk7TsNG9qlOt0f</param>
        /// <param name="accessKeySecret"> keysecret : wTXHa3xHApjEcz1uKCwnEPCgZUiCXf</param>
        /// <param name="endpoint">接入点 : oss-cn-hangzhou.aliyuncs.com</param>
        /// <param name="bucket">存储名称 : jc-file</param>
        public OSS(string accessKeyId, string accessKeySecret, string endpoint, string bucket)
        {
            this.accessKeyId = accessKeyId;
            this.accessKeySecret = accessKeySecret;
            this.bucket = bucket;
            this.host = "https://" + bucket + "." + endpoint;
            this.endpoint = "https://" + endpoint;
        }


        /// <summary>
        /// 将Unix时间戳转换为DateTime类型时间
        /// </summary>
        /// <param name="d">double 型数字</param>
        /// <returns>DateTime</returns>
        public static System.DateTime ConvertIntDateTime(double d)
        {
            System.DateTime time = System.DateTime.MinValue;
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            time = startTime.AddMilliseconds(d);
            return time;
        }


        /// <summary>
        /// 将c# DateTime时间格式转换为Unix时间戳格式
        /// </summary>
        /// <param name="time">时间</param>
        /// <returns>long</returns>
        public static long ConvertDateTimeInt(System.DateTime time)
        {
            //double intResult = 0;
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1, 0, 0, 0, 0));
            //intResult = (time- startTime).TotalMilliseconds;
            long t = (time.Ticks - startTime.Ticks) / 10000;            //除10000调整为13位
            return t;
        }


        public static string ToBase64hmac(string strText, string strKey)
        {
            HMACSHA1 myHMACSHA1 = new HMACSHA1(Encoding.UTF8.GetBytes(strKey));
            byte[] byteText = myHMACSHA1.ComputeHash(Encoding.UTF8.GetBytes(strText));
            return System.Convert.ToBase64String(byteText);
        }


        /// <summary>
        /// 获取上传验证配置
        /// </summary>
        /// <param name="dir">目录: 12/userpic/</param>
        /// <param name="expireTime">过期时间（分钟）</param>
        /// <returns></returns>
        public UploadCode GetUploadCode(string dir, string fileName, int expireTime)
        {
            /// <summary>
            /// 由用户指定的OSS访问地址、阿里云颁发的AccessKeyId/AccessKeySecret构造一个新的OssClient实例。
            /// </summary>
            /// <param name="endpoint">OSS的访问地址。</param>
            /// <param name="accessKeyId">OSS的访问ID。</param>
            /// <param name="accessKeySecret">OSS的访问密钥。</param>
            var ossClient = new OssClient(endpoint, accessKeyId, accessKeySecret);
            long expireEndTime = ConvertDateTimeInt(DateTime.Now.AddMinutes(expireTime));
            DateTime expiration = ConvertIntDateTime(expireEndTime);

            PolicyConditions policyConds = new PolicyConditions();
            policyConds.AddConditionItem(PolicyConditions.CondContentLengthRange, 0, 1048576000);
            policyConds.AddConditionItem(MatchMode.StartWith, PolicyConditions.CondKey, dir + fileName + ".");

            String postPolicy = ossClient.GeneratePostPolicy(expiration, policyConds);
            byte[] binaryData = Encoding.UTF8.GetBytes(postPolicy);
            String encodedPolicy = Convert.ToBase64String(binaryData);
            String postSignature = ToBase64hmac(encodedPolicy, accessKeySecret);

            UploadCode s = new UploadCode();
            s.accessid = accessKeyId;
            s.host = host;
            s.policy = encodedPolicy;
            s.signature = postSignature;
            s.expire = expireEndTime.ToString();
            s.dir = dir;
            s.filename = fileName;
            return s;
        }


        /// <summary>
        /// 上传文件
        /// </summary>
        /// <param name="localFile">本地文件</param>
        /// <param name="ossFile">上传后文件</param>
        /// <returns></returns>
        public bool UploadFile(string localFile, string ossFile)
        {
            if (System.IO.File.Exists(localFile))
            {
                var ossClient = new OssClient(endpoint, accessKeyId, accessKeySecret);
                var result = ossClient.PutObject(bucket, ossFile, localFile);
                System.IO.File.Delete(localFile);

                return true;
            }
            else
            {
                return false;
            }

        }

        /// <summary>
        /// 上传文件
        /// </summary>
        /// <param name="OssFileName">上传后文件名</param>
        /// <param name="FileStream">文件流</param>
        /// <returns>是否成功</returns>
        public bool UploadFile(string OssFileName, Stream FileStream)
        {
            if (FileStream == null)
            {
                return false;
            }

            var ossClient = new OssClient(endpoint, accessKeyId, accessKeySecret);
            var result = ossClient.PutObject(bucket, OssFileName, FileStream);
            return true;
        }
    }


    public class UploadCode
    {
        public string accessid { get; set; }

        public string host { get; set; }

        public string policy { get; set; }

        public string signature { get; set; }

        public string expire { get; set; }

        public string dir { get; set; }

        public string filename { get; set; }

    }
}