root/platform/silverlight/eLearn/trunk/eLearn_Web/Controllers/StudyController.cs @ 14667

#region license
/*
Copyright (c) 2008, Kouji Yamaguchi
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

* Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

* Neither the name of coma2n nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#endregion

#region namespaces

using System;
using System.IO;
using System.Web;
using System.Web.Mvc;
using System.Net;
using System.Linq;
using System.Text;
using System.Xml.Linq;
using System.Diagnostics;

using Ele = System.Xml.Linq.XElement;
using Attr = System.Xml.Linq.XAttribute;

#endregion

namespace eLearn_Web.Controllers {

    #region StudyController class

    /// <summary>
    /// スタディに関する情報をやり取りするコントローラクラス
    /// </summary>
    public sealed class StudyController : Controller {

        #region const

        /// <summary>
        /// インデックスファイル
        /// </summary>
        private const string INDEX_FILE = "~/App_Data/Repo/index.xml";
        /// <summary>
        /// コンテントファイルのフォーマット
        /// </summary>
        private const string CONTENT_FILE_FORMAT = "~/App_Data/Repo/study/{0}.xml";

        #endregion

        #region constructors

        /// <summary>
        /// 標準的なコンストラクタ
        /// </summary>
        public StudyController() {
        }

        #endregion

        #region methods

        /// <summary>
        /// スタディ情報の一覧を取得します。
        /// </summary>
        /// <returns>スタディ情報の一覧</returns>
        public ActionResult Index() {
            var path = Request.MapPath(INDEX_FILE);

            using(var sr = new StreamReader(path, Encoding.UTF8)) {
                return Content(sr.ReadToEnd(), "text/xml");
            }
        }

        /// <summary>
        /// 指定したIdのスタディの情報を取得します。
        /// </summary>
        /// <param name="id">Id</param>
        /// <returns>スタディ情報</returns>
        public ActionResult Get(int? id) {
            if(id != null) {
                try {
                    var path = Request.MapPath(string.Format(CONTENT_FILE_FORMAT, id));

                    using(var sr = new StreamReader(path, Encoding.UTF8)) {
                        return Content(sr.ReadToEnd(), "text/xml");
                    }

                } catch(Exception exp) {
                    throw new HttpException((int)HttpStatusCode.NotFound, "指定したStudyは存在しません。", exp);
                }

            } else {
                throw new HttpException((int)HttpStatusCode.BadRequest, "[id]を指定して下さい。");
            }
        }

        /// <summary>
        /// スタディを新規作成します。
        /// </summary>
        /// <param name="title">タイトル</param>
        /// <returns>スタディ情報</returns>
        public ActionResult New(string title) {
            if(string.IsNullOrEmpty(title)) {
                throw new HttpException((int)HttpStatusCode.BadRequest, "[title]を指定して下さい。");
            }
            var indexXml = OpenIndex();
            var id = indexXml.Descendants("study").Max(s => (int)s.Attribute("id")) + 1;

            indexXml.Root.Add(
                new Ele("study",
                    new Attr("id", id), new Attr("title", title)
                )
            );
            SaveIndex(indexXml);

            var contentXml = new XDocument(
                new Ele("study",
                    new Attr("id", id), new Attr("title", title)
                )
            );
            return Content(
                SaveContent(contentXml, id).ToString(), "text/xml"
            );
        }

        /// <summary>
        /// 指定したIdのスタディを削除します。
        /// </summary>
        /// <param name="id">Id</param>
        /// <returns>削除できたかどうか</returns>
        public ActionResult Remove(int? id) {
            if(id == null) {
                throw new HttpException((int)HttpStatusCode.BadRequest, "[id]を指定して下さい。");
            }
            var indexXml = OpenIndex();

            var study = indexXml.Descendants("study")
                .FirstOrDefault(s => (int)s.Attribute("id") == id.Value);

            if(study == null) {
                throw new HttpException((int)HttpStatusCode.NotFound, "指定したStudyは存在しません。");
            }
            study.Remove();

            SaveIndex(indexXml);

            return Content("0", "text/plain");
        }

        /// <summary>
        /// 指定したIdのスタディに指定した質問を追加します。
        /// </summary>
        /// <param name="id">Id</param>
        /// <param name="content">質問内容を表すXML</param>
        /// <returns>スタディ情報</returns>
        public ActionResult AddQuestion(int? id, string content) {
            if(id == null || string.IsNullOrEmpty(content)) {
                throw new HttpException((int)HttpStatusCode.BadRequest, "[id][content]を指定して下さい。");
            }
            var xml = OpenContent(id);
            xml.Root.Add(content);

            return Content(
                SaveContent(xml, id).ToString(), "text/xml"
            );
        }

        /// <summary>
        /// 指定したIdのスタディの指定した位置の質問を削除します。
        /// </summary>
        /// <param name="id">Id</param>
        /// <param name="index">質問の位置</param>
        /// <returns>削除後のスタディ情報</returns>
        public ActionResult RemoveQuestion(int? id, int? index) {
            if(id == null || index == null) {
                throw new HttpException((int)HttpStatusCode.BadRequest, "[id][index]を指定して下さい。");
            }
            var contentXml = OpenContent(id);
            // 一度リストに変換しないと駄目よ！！
            contentXml.Descendants("question")
                .Where((q, i) => i == index)
                .ToList().ForEach(q => q.Remove());
            
            return Content(
                SaveContent(contentXml, id).ToString(), "text/xml"
            );
        }

        #region private

        /// <summary>
        /// インデックスファイルを開きます。
        /// </summary>
        /// <returns>インデックスファイル</returns>
        XDocument OpenIndex() {
            return XDocument.Load(Request.MapPath(INDEX_FILE));
        }

        /// <summary>
        /// 指定したインデックスを保存します。
        /// </summary>
        /// <param name="xml">インデックス</param>
        /// <returns>インデックス</returns>
        XDocument SaveIndex(XDocument xml) {
            xml.Save(Request.MapPath(INDEX_FILE));

            return xml;
        }

        /// <summary>
        /// 指定したIdのコンテントを開きます。
        /// </summary>
        /// <param name="id">Id</param>
        /// <returns>コンテント</returns>
        XDocument OpenContent(int? id) {
            return XDocument.Load(
                Request.MapPath(string.Format(CONTENT_FILE_FORMAT, id))
            );
        }

        /// <summary>
        /// 指定したコンテントを保存します。
        /// </summary>
        /// <param name="xml">コンテント</param>
        /// <param name="id">Id</param>
        /// <returns>コンテント</returns>
        XDocument SaveContent(XDocument xml, int? id) {
            xml.Save(
                Request.MapPath(string.Format(CONTENT_FILE_FORMAT, id))
            );
            return xml;
        }

        #endregion

        #endregion

    }

    #endregion

}