using System;
using System.Web;
using System.Data;
using System.IO;

using Discuz.Common;
using Discuz.Forum;
using Discuz.Config;
using Discuz.Web.UI;
using Discuz.Entity;
using Discuz.Plugin.Mall;

namespace Discuz.Web
{
    /// <summary>
    /// attachment页的类派生于BasePage类
    /// </summary>
    public class attachment : PageBase
    {
        #region 变量声明
        /// <summary>
        /// 附件所属主题信息
        /// </summary>
        public TopicInfo topic;
        /// <summary>
        /// 附件信息
        /// </summary>
        public AttachmentInfo attachmentinfo;
        /// <summary>
        /// 附件Id
        /// </summary>
        public int attachmentid = DNTRequest.GetInt("attachmentid", -1);
        /// <summary>
        /// 是否需要登录后进行下载
        /// </summary>
        public bool needlogin = false;
        /// <summary>
        /// 附件商品信息
        /// </summary>
        public Goodsinfo goodsinfo;
        /// <summary>
        /// 商品附件信息
        /// </summary>
        public Goodsattachmentinfo goodsattachmentinfo;
        /// <summary>
        /// 版块信息
        /// </summary>
        public ForumInfo forum;
        /// <summary>
        /// 错误提示信息
        /// </summary>
        private string msg = "";
        #endregion 变量声明

        protected override void ShowPage()
        {
            pagetitle = "附件下载";

            if (attachmentid == -1)
            {
                AddErrLine("无效的附件ID");
                return;
            }

            //　如果当前用户非管理员并且论坛设定了禁止下载附件时间段，当前时间如果在其中的一个时间段内，则不允许用户下载附件
            if (useradminid != 1 && usergroupinfo.Disableperiodctrl != 1)
            {
                string visitTime = "";
                if (Scoresets.BetweenTime(config.Attachbanperiods, out visitTime))
                {
                    AddErrLine("在此时间段( " + visitTime + " )内用户不可以下载附件");
                    return;
                }
            }

            if (DNTRequest.GetString("goodsattach").ToLower() == "yes")
                GetGoodsAttachInfo(attachmentid);
            else
            {
                // 获取该附件的信息
                attachmentinfo = Attachments.GetAttachmentInfo(attachmentid);
                if (attachmentinfo == null)
                {
                    AddErrLine("不存在的附件ID");
                    return;
                }
                //当前用户已上传但是还没有绑定到帖子的附件需要特殊处理，直接输出图片
                if (userid > 0 && userid == attachmentinfo.Uid && attachmentinfo.Tid == 0 && attachmentinfo.Filetype.StartsWith("image/"))
                {
                    HttpContext.Current.Response.Clear();
                    HttpContext.Current.Response.Redirect(attachmentinfo.Filename.IndexOf("http") < 0 ? BaseConfigs.GetForumPath + "upload/" + attachmentinfo.Filename.Trim() : attachmentinfo.Filename.Trim());
                    HttpContext.Current.Response.End();
                    return;
                }
                // 获取该主题的信息
                topic = Topics.GetTopicInfo(attachmentinfo.Tid);
                if (topic == null)
                {
                    AddErrLine("不存在的主题ID");
                    return;
                }

                ForumInfo forum = Forums.GetForumInfo(topic.Fid);
                pagetitle = Utils.RemoveHtml(forum.Name);
                if (!UserAuthority.VisitAuthority(forum, usergroupinfo, userid, ref msg))
                {
                    AddErrLine(msg);
                    if (userid == -1)
                        needlogin = true;
                    return;
                }

                //添加判断特殊用户的代码
                if (!UserAuthority.CheckUsertAttachAuthority(forum, usergroupinfo, userid, ref msg))
                {
                    AddErrLine(msg);
                    if (userid == -1)
                        needlogin = true;
                    return;
                }
                // 检查用户是否拥有足够的阅读权限
                if ((attachmentinfo.Readperm > usergroupinfo.Readaccess) && (attachmentinfo.Uid != userid) && (!Moderators.IsModer(useradminid, userid, forum.Fid)))
                {
                    AddErrLine("您的阅读权限不够");
                    if (userid == -1)
                        needlogin = true;
                    return;
                }

                //检查附件是否存在
                if (attachmentinfo.Filename.IndexOf("http") < 0 && !File.Exists(Utils.GetMapPath(string.Format(@"{0}upload/{1}", BaseConfigs.GetForumPath, attachmentinfo.Filename))))
                {
                    AddErrLine("该附件文件不存在或已被删除");
                    return;
                }

                //如果图片是不直接显示(作为附件显示) 并且不是作者本人下载都会扣分,并判断是否已经下载过，如果下载过则不再扣积分
                //if ((config.Showimages != 1 || !Utils.IsImgFilename(attachmentinfo.Filename.Trim()) && 
                //    userid != attachmentinfo.Uid) && Utils.StrIsNullOrEmpty(Utils.GetCookie("dnt_attachment_" + attachmentid)))
                if ((!Utils.IsImgFilename(attachmentinfo.Filename.Trim()) || config.Showimages != 1) &&
                    (userid != attachmentinfo.Uid && Utils.StrIsNullOrEmpty(Utils.GetCookie("dnt_attachment_" + attachmentid))))
                {
                    if (Scoresets.IsSetDownLoadAttachScore() && UserCredits.UpdateUserExtCreditsByDownloadAttachment(userid, 1) == -1)
                    {
                        string addExtCreditsTip = "";
                        if (EPayments.IsOpenEPayments())
                            addExtCreditsTip = "<br/><span><a href=\"usercpcreditspay.aspx\">点击充值积分</a></span>";
                        AddErrLine("您的积分不足" + addExtCreditsTip);
                        return;
                    }
                    //设置该附件已经下载的cookie
                    Utils.WriteCookie("dnt_attachment_" + attachmentid, "true", 5);
                }

                //检查附件是否存在
                if (AttachPaymentLogs.HasBoughtAttach(userid, usergroupinfo.Radminid, attachmentinfo))
                {
                    AddErrLine("该附件为交易附件, 请先行购买!");
                    return;
                }

                Attachments.UpdateAttachmentDownloads(attachmentid);

                if (attachmentinfo.Filename.IndexOf("http") < 0)
                    Utils.ResponseFile(Utils.GetMapPath(BaseConfigs.GetForumPath + @"upload/" + attachmentinfo.Filename), Path.GetFileName(attachmentinfo.Attachment), attachmentinfo.Filetype);
                else
                {
                    try //添加try语法, 以防止在并发访问情况下, 服务器端远程链接被关闭后出现应用程序 '警告'(事件查看器)
                    {
                        HttpContext.Current.Response.Clear();
                        HttpContext.Current.Response.Redirect(attachmentinfo.Filename.Trim());
                        HttpContext.Current.Response.End();
                    }
                    catch{}                    
                }
            }
        }

        public void GetGoodsAttachInfo(int attachmentid)
        {
            MallPluginBase mpb = MallPluginProvider.GetInstance();
            if (mpb == null)
            {
                AddErrLine("未安装商城插件");
                return;
            }
            goodsattachmentinfo = mpb.GetGoodsAttachmentsByAid(attachmentid);
            if (goodsattachmentinfo == null)
            {
                AddErrLine("不存在的附件ID");
                return;
            }
            // 获取该商品的信息
            goodsinfo = mpb.GetGoodsInfo(goodsattachmentinfo.Goodsid);
            if (goodsinfo == null)
            {
                AddErrLine("不存在的商品ID");
                return;
            }

            forum = Forums.GetForumInfo(mpb.GetCategoriesFid(goodsinfo.Categoryid));
            pagetitle = Utils.RemoveHtml(forum.Name);

            //添加判断特殊用户的代码
            if (!Forums.AllowViewByUserId(forum.Permuserlist, userid) && !Forums.AllowView(forum.Viewperm, usergroupid))
            {
                AddErrLine("您没有浏览该版块的权限");
                if (userid == -1)
                    needlogin = true;
                return;
            }

            //添加判断特殊用户的代码
            if (!UserAuthority.CheckUsertAttachAuthority(forum, usergroupinfo, userid, ref msg))
            {
                AddErrLine(msg);
                if (userid == -1)
                    needlogin = true;
                return;
            }
            // 检查用户是否拥有足够的阅读权限
            if (goodsattachmentinfo.Readperm > usergroupinfo.Readaccess && goodsattachmentinfo.Uid != userid && !Moderators.IsModer(useradminid, userid, forum.Fid))
            {
                AddErrLine("您的阅读权限不够");
                if (userid == -1)
                    needlogin = true;
                return;
            }
            if (goodsattachmentinfo.Filename.IndexOf("http") < 0 && !File.Exists(Utils.GetMapPath(string.Format(@"{0}upload/{1}", BaseConfigs.GetForumPath, goodsattachmentinfo.Filename))))
            {
                AddErrLine("该附件文件不存在或已被删除");
                return;
            }

            if (goodsattachmentinfo.Filename.IndexOf("http") < 0)
                Utils.ResponseFile(Utils.GetMapPath(string.Format(@"{0}upload/{1}", BaseConfigs.GetForumPath, goodsattachmentinfo.Filename)), Path.GetFileName(goodsattachmentinfo.Attachment), goodsattachmentinfo.Filetype);
            else
                HttpContext.Current.Response.Redirect(goodsattachmentinfo.Filename.Trim());
        }
    }
}