取得Xuite隨意窩影音的真實位址與其他資訊

GetXuiteMedia

/*
	Date:20141207
	BY XPY
	程式碼僅供參考，引用請標示本頁網址
*/
using System;
using System.Linq;
using System.Text;
using System.Xml;
using System.Collections;
using System.Collections.Generic;
using Alex.Syntax;//額外的擴充，簡化寫法(String.InnerString、ArrayList.ToArray<Type>())
using Alex.Data;//KeyValueCollection(可用Dictionary替代)

namespace Alex.Social.MediaGet.Parsers {
    public class XuiteParser : Parser {//中華電信隨意窩影音剖析器
        public override MediaInfo[] GetMediaInfos(Uri Uri) {
            if(!IsMatch(Uri))//檢查網址是否符合規範
                throw new UriNotMatchException(Uri);//如果不符合網址規範返回例外

            string ApiUrlString
                = string.Format("http://vlog.xuite.net/flash/player?media={0}"
                    ,Uri.EscapeDataString(GetMediaId(Uri)));//將ID帶入API網址且將ID轉換為百分比編碼

            KeyValueCollection Data = GetApiData(ApiUrlString);//取得媒體資料

            ArrayList result = new ArrayList();//結果回傳集合

            MediaType Type = ((string)Data["type"])=="audio" ?
                MediaType.Audio : MediaType.Video;//判別型別是否為影片或音樂檔

            //建立屬性樣板
            KeyValueCollection Attributes = new KeyValueCollection();//其餘的媒體屬性資料集合
            Attributes.Add(Data.GetWithKey("author_name"));
            Attributes.Add(Data.GetWithKey("thumb"));
            Attributes.Add(Data.GetWithKey("category"));
            Attributes.Add(Data.GetWithKey("duration"));
            Attributes.Add(Data.GetWithKey("description"));
            Attributes.AddWithValue("type",Type == MediaType.Video ? "mp4" : "mp3");

            if(Type == MediaType.Video)
                Attributes.Add(Data.GetWithKey("size"));//如果為影片則有SIZE屬性

            if(Data.HasKey("src")) {
                KeyValueCollection ItemAttr = Attributes.Clone();//複製屬性集合
                ItemAttr.AddWithValue("quality" ,"default");//SRC為預設品質
                MediaInfo Item = new MediaInfo() {
                    Name = Data["title"] as string ,
                    Parser = ParserEnum.Xuite ,
                    SourceUrl = Uri ,
                    Type = Type ,
                    RealUrl = new Uri[] { new Uri((string)Data["src"]) } ,
                    Attributes = ItemAttr
                };
                result.Add(Item);//加入結果
            }
            if(Data.HasKey("hq_src")) {//有HQ
                KeyValueCollection ItemAttr = Attributes.Clone();//複製屬性集合
                ItemAttr.AddWithValue("quality" ,"hq");//品質
                MediaInfo Item = new MediaInfo() {
                    Name = Data["title"] as string ,
                    Parser = ParserEnum.Xuite ,
                    SourceUrl = Uri ,
                    Type = Type ,
                    RealUrl = new Uri[] { new Uri((string)Data["hq_src"]) } ,
                    Attributes = ItemAttr
                };
                result.Add(Item);//加入結果
            }
            if(Data.HasKey("hd1080_src")) {//有HD
                KeyValueCollection ItemAttr = Attributes.Clone();//複製屬性集合
                ItemAttr.AddWithValue("quality" ,"hd1080");//品質
                MediaInfo Item = new MediaInfo() {
                    Name = Data["title"] as string ,
                    Parser = ParserEnum.Xuite ,
                    SourceUrl = Uri ,
                    Type = Type ,
                    RealUrl = new Uri[] { new Uri((string)Data["hd1080_src"]) } ,
                    Attributes = ItemAttr
                };
                result.Add(Item);//加入結果
            }

            if(result.Count == 0)
                throw new ParserException();//剖析失敗

            return result.ToArray<MediaInfo>();//轉回MediaInfo[]
        }

        //由網址取得媒體ID
        private string GetMediaId(Uri Uri) {
            string UndecodingId = Uri.Segments.Last<string>();//最後一個網址區間為XuiteID的BASE64型態
            try {
                string DecodingId = DecodingStringFromBase64(UndecodingId);//呼叫解碼方法
                DecodingId = DecodingId.InnerString("-",".");//-與.之間才是媒體ID(數字碼)
                DecodingId = EncodingBase64FromString(DecodingId);//將ID數字轉換為BASE64
                return DecodingId;
            } catch {
                throw new UriNotMatchException(Uri);//如果不能做Base64解碼，表示網址有問題
            }
        }

        //將BASE64的字串還原回普通字串資料
        private string DecodingStringFromBase64(string Data) {
            byte[] Base64ByteArray = Convert.FromBase64String(Data);//將BASE64字串轉換為Byte陣列
            return Encoding.UTF8.GetString(Base64ByteArray);//預設使用UTF8
        }

        //將字串轉為BASE64字串
        private string EncodingBase64FromString(string Data) {
            byte[] ByteArray = Encoding.UTF8.GetBytes(Data);//將字串轉換為Byte陣列
            return Convert.ToBase64String(ByteArray);//轉換為BASE64字串
        }

        private KeyValueCollection GetApiData(string ApiUrlString) {
            XmlDocument ApiResult = new XmlDocument();
            ApiResult.Load(ApiUrlString);//讀取API回傳結果

            XmlNodeList Properties = ApiResult.SelectNodes("//property");//取得屬性節點集合

            KeyValueCollection Data = new KeyValueCollection();
            foreach(XmlNode Property in Properties) {//迴圈讀取所有屬性節點資料
                string PropertyName = DecodingStringFromBase64(Property.Attributes["id"].Value);
                //取得屬性的名稱

                string PropertyValue = Uri.UnescapeDataString(DecodingStringFromBase64(Property.InnerText));
                //取得屬性的值

                if(string.IsNullOrWhiteSpace(PropertyValue))
                    continue;
                //如果為空字串則該屬性不用加入值組物件中

                Data.AddWithValue(PropertyName ,PropertyValue);//加入值組物件
            }
            return Data;//回傳
        }
    }
}