VersionCheckerV2.cs

/*
弹幕姬中已有 Newtonsoft.Json 7.0.1
尽量使用相同版本，避免重复加载不同版本之类的问题

using Newtonsoft.Json.Linq;
using System;
using System.IO;
using System.Net;

*/

internal class VersionChecker
{
    #region -- 常量 --

    /// <summary>
    /// 默认服务器地址
    /// </summary>
    public const string DEFAULT_BASE_URL = "https://www.danmuji.org";

    /// <summary>
    /// API的路径
    /// </summary>
    public const string API_PATH = "/api/v2/";

    /// <summary>
    /// 插件介绍页的路径
    /// </summary>
    public const string WEB_PATH = "/plugins/";

    #endregion

    #region -- 变量 --
    private string BaseUrl;

    /// <summary>
    /// 最后一个出错的Exception
    /// </summary>
    public Exception lastException { get; private set; } = null;

    /// <summary>
    /// 插件ID
    /// </summary>
    public string Id { get; private set; } = "example";

    /// <summary>
    /// API返回的插件名字
    /// </summary>
    public string Name { get; private set; }

    /// <summary>
    /// API返回的插件作者
    /// </summary>
    public string Author { get; private set; }

    /// <summary>
    /// API返回的最新版本号
    /// </summary>
    public Version Version { get; private set; }

    /// <summary>
    /// API返回的插件说明
    /// </summary>
    public string Description { get; private set; }

    /// <summary>
    /// API返回的更新时间
    /// </summary>
    public DateTime UpdateDateTime { get; private set; }

    /// <summary>
    /// API返回的更新说明
    /// </summary>
    public string UpdateDescription { get; private set; }

    /// <summary>
    /// API返回的下载地址
    /// </summary>
    public Uri DownloadUrl { get; private set; }

    /// <summary>
    /// 用户查看用的页面地址
    /// </summary>
    public Uri WebPageUrl
    {
        get
        { return new Uri(this.BaseUrl + WEB_PATH + this.Id); }
    }

    /// <summary>
    /// API返回的下载说明
    /// </summary>
    public string DownloadNote { get; private set; }

    #endregion

    /// <summary>
    /// 新建一个版本检查类
    /// </summary>
    /// <param name="id">插件ID</param>
    public VersionChecker(string id) : this(id, DEFAULT_BASE_URL)
    { }

    /// <summary>
    /// 新建一个指定服务器地址的版本检查类
    /// </summary>
    /// <param name="id">插件ID</param>
    /// <param name="baseurl">服务器地址</param>
    public VersionChecker(string id, string baseurl)
    {
        this.Id = id;
        this.BaseUrl = baseurl;
    }

    /// <summary>
    /// 从服务器获取信息
    /// </summary>
    /// <returns>获取是否成功</returns>
    public bool FetchInfo()
    {
        try
        {
            Uri fullUri = new Uri(BaseUrl + API_PATH + this.Id);
            string json = HttpGet(fullUri);
            JObject j = JObject.Parse(json);

            if(j["id"].ToString() != this.Id)
            { lastException = new Exception("API返回ID不正确"); return false; }
            else
            {
                this.Name = j["name"].ToString();
                this.Author = j["author"].ToString();
                this.Version = new Version(j["version"].ToString());
                this.Description = j["description"].ToString();

                //this.UpdateTime = DateTime.ParseExact(j["updatetime"].ToString(), "yyyy.MM.dd", CultureInfo.InvariantCulture);
                this.UpdateDateTime = DateTimeOffset.Parse(j["update_datetime"].ToString(), null).DateTime;
                this.UpdateDescription = j["update_desc"].ToString();

                //this.DownloadUrl = j["dl_url"].ToString().StartsWith("http") ? new Uri(j["dl_url"].ToString()) : new Uri(this.BaseUrl + j["dl_url"].ToString());
                this.DownloadUrl = new Uri(new Uri(this.BaseUrl), j["dl_url"].ToString());
                this.DownloadNote = j["dl_note"].ToString();

                return true;
            }
        }
        catch(Exception ex)
        { lastException = ex; return false; }

    }

    /// <summary>
    /// 检查是否具有更新的版本
    /// </summary>
    /// <param name="version">当前版本号</param>
    /// <returns>检查结果</returns>
    public bool hasNewVersion(string version)
    { return hasNewVersion(new Version(version)); }

    /// <summary>
    /// 检查是否具有更新的版本
    /// </summary>
    /// <param name="version">当前版本号</param>
    /// <returns>检查结果</returns>
    public bool hasNewVersion(Version version)
    { return (version.CompareTo(this.Version) < 0); }
    // version对象比参数小（之前，older的版本）


    private string HttpGet(Uri uri)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
        //request.AutomaticDecompression = DecompressionMethods.GZip;
        using(HttpWebResponse response = (HttpWebResponse)request.GetResponse())
        using(Stream stream = response.GetResponseStream())
        using(StreamReader reader = new StreamReader(stream))
        { var text = reader.ReadToEnd(); return text; }
    }
}