using System;
using System.Collections.Generic;

using System.Text;
using COSXML.Common;
using COSXML.CosException;
using System.IO;

namespace COSXML.Model.Object
{
    /// <summary>
    /// 下载对象
    /// <see href="https://cloud.tencent.com/document/product/436/7753"/>
    /// </summary>
    public sealed class GetObjectRequest : ObjectRequest
    {
        /// <summary>
        /// 保存文件的本地文件夹路径
        /// </summary>
        public string localDir;

        /// <summary>
        /// 保存文件的本地的文件名
        /// </summary>
        public string localFileName;

        /// <summary>
        /// 保存文件的本地偏移位置，下载的数据从此处开始append该文件后面
        /// </summary>
        private long localFileOffset = 0;

        /// <summary>
        /// 下载进度回调
        /// </summary>
        private COSXML.Callback.OnProgressCallback progressCallback;


        public GetObjectRequest(string bucket, string key, string localDir, string localFileName)
            : base(bucket, key)
        {
            this.method = CosRequestMethod.GET;
            this.localDir = localDir;
            this.localFileName = localFileName;
        }

        /// <summary>
        /// 下载进度回调
        /// </summary>
        /// <param name="progressCallback"></param>
        public void SetCosProgressCallback(COSXML.Callback.OnProgressCallback progressCallback)
        {
            this.progressCallback = progressCallback;
        }

        internal COSXML.Callback.OnProgressCallback GetCosProgressCallback()
        {

            return progressCallback;
        }

        /// <summary>
        /// 保存文件的本地偏移位置，下载的数据从此处开始append该文件后面
        /// </summary>
        /// <param name="localFileOffset"></param>
        public void SetLocalFileOffset(long localFileOffset)
        {
            this.localFileOffset = localFileOffset > 0 ? localFileOffset : 0;
        }

        public long GetLocalFileOffset()
        {

            return localFileOffset;
        }

        /// <summary>
        /// 下载内容范围
        /// </summary>
        /// <param name="start"></param>
        /// <param name="end"></param>
        public void SetRange(long start, long end)
        {

            if (start < 0)
            {

                return;
            }

            if (end < start)
            {
                end = -1;
            }

            SetRequestHeader(CosRequestHeaderKey.RANGE, String.Format("bytes={0}-{1}", start,
                (end == -1 ? "" : end.ToString())));

        }

        /// <summary>
        /// 下载内容的起始偏移量
        /// </summary>
        /// <param name="start"></param>
        public void SetRange(long start)
        {
            SetRange(start, -1);
        }

        /// <summary>
        /// 最大下载速度，单位是 bit/s
        /// </summary>
        /// <param name="rate"></param>
        public void LimitTraffic(long rate)
        {
            SetRequestHeader(CosRequestHeaderKey.X_COS_TRAFFIC_LIMIT, rate.ToString());
        }

        /// <summary>
        /// 下载特定版本的对象
        /// </summary>
        /// <param name="versionId"></param>
        public void SetVersionId(string versionId)
        {

            if (versionId != null)
            {
                SetQueryParameter(CosRequestHeaderKey.VERSION_ID, versionId);
            }
        }

        public override void CheckParameters()
        {

            if (localDir == null)
            {
                throw new CosClientException((int)CosClientError.InvalidArgument, "localDir = null");
            }

            if (requestUrlWithSign != null && localFileName == null)
            {
                throw new CosClientException((int)CosClientError.InvalidArgument, "localFileName = null");
            }

            base.CheckParameters();
        }

        /// <summary>
        /// 获取本地文件保存路径
        /// </summary>
        /// <returns></returns>
        public string GetSaveFilePath()
        {
            string result = localDir;
            DirectoryInfo dirInfo = new DirectoryInfo(localDir);

            if (!dirInfo.Exists)
            {
                dirInfo.Create();
            }

            if (String.IsNullOrEmpty(localFileName))
            {
                localFileName = path;
            }

            if (localDir.EndsWith(System.IO.Path.DirectorySeparatorChar.ToString(), StringComparison.OrdinalIgnoreCase))
            {
                result = result + localFileName;
            }
            else
            {
                result = result + System.IO.Path.DirectorySeparatorChar + localFileName;
            }

            return result;
        }
    }
}