apewer-dotnet/Apewer/Web/StaticController.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace Apewer.Web
{

    /// <summary>静态站点控制器。</summary>
    public class StaticController : ApiController
    {

        #region 初始化

        Func<StaticController, JumpStatement> _initializer = null;
        Class<string> _root = null;

        /// <summary></summary>
        public StaticController() : base((c) => { ((StaticController)c).Initialize(); return false; }) { }

        /// <summary></summary>
        public StaticController(Func<StaticController, JumpStatement> initializer) : base((c) => { ((StaticController)c).Initialize(); return false; })
        {
            _initializer = initializer;
        }

        void Initialize()
        {
            if (Request == null || Request.Url == null) return;

            if (_initializer != null)
            {
                var jump = _initializer.Invoke(this);
                if (jump == JumpStatement.Break) return;
            }

            // 获取相对路径
            var urlPath = GetUrlPath();
            if (string.IsNullOrEmpty(urlPath)) return;

            // 内置的处理程序
            ApiUtility.StopReturn(Response);
            Execute(urlPath);
        }

        #endregion

        #region 自定义

        /// <summary>允许服务器端包含（Server Side Include）。</summary>
        /// <remarks>默认值：允许。</remarks>
        protected bool AllowSSI { get; set; } = true;

        /// <summary>允许 GetRoot 方法访问应用程序目录。</summary>
        /// <remarks>默认值：不允许。</remarks>
        protected bool AllowApplicationPath { get; set; } = false;

        /// <summary>获取已解析的站点根目录。</summary>
        protected string Root { get => _root?.Value; }

        /// <summary>执行路径。</summary>
        protected virtual void Execute(string urlPath)
        {
            // 自定义处理
            var model = GetModel(urlPath);
            if (model != null)
            {
                Response.Model = model;
                return;
            }

            // 自定义处理
            var result = GetResult(urlPath);
            if (result != null)
            {
                Response.Model = result;
                return;
            }

            InternalExecute(urlPath);
        }

        /// <summary>获取此静态站点的目录。</summary>
        protected virtual string GetRoot()
        {
            if (_root) return _root.Value;
            var app = RuntimeUtility.ApplicationPath;

            var paths = StorageUtility.GetSubFiles(app);
            foreach (var path in paths)
            {
                var split = path.Split('/', '\\');
                var lower = split[split.Length - 1];
                switch (lower)
                {
                    case "index.html":
                    case "index.htm":
                    case "default.html":
                    case "default.htm":
                    case "favicon.ico":
                        _root = new Class<string>(app);
                        return app;
                }
            }

            var www = StorageUtility.CombinePath(app, "www");
            if (System.IO.Directory.Exists(www))
            {
                _root = new Class<string>(www);
                return www;
            }

            var web = StorageUtility.CombinePath(app, "web");
            if (System.IO.Directory.Exists(web))
            {
                _root = new Class<string>(web);
                return web;
            }

            var @static = StorageUtility.CombinePath(app, "static");
            if (System.IO.Directory.Exists(@static))
            {
                _root = new Class<string>(@static);
                return @static;
            }

            if (AllowApplicationPath)
            {
                _root = new Class<string>(app);
                return app;
            }
            else
            {
                _root = new Class<string>(null);
                return null;
            }
        }

        /// <summary>获取 URL 路径。</summary>
        protected virtual string GetUrlPath() => Request.Url.AbsolutePath;

        /// <summary>获取响应结果。</summary>
        protected virtual IActionResult GetResult(string urlPath) => null;

        /// <summary>获取响应结果。</summary>
        protected virtual ApiModel GetModel(string urlPath) => null;

        /// <summary>加载 Web.zip 文件。</summary>
        protected virtual Dictionary<string, byte[]> LoadWebZip()
        {
            var names = new string[] { "Web.zip", "web.zip" };

            foreach (var name in names)
            {
                var path = StorageUtility.CombinePath(RuntimeUtility.ApplicationPath, name);
                if (StorageUtility.FileExists(path))
                {
                    var data = StorageUtility.ReadFile(path);
                    var dict = BytesUtility.FromZip(data);
                    return dict;
                }
            }

            return null;
        }

        /// <summary>从扩展名获取内容类型。</summary>
        protected virtual string ContentType(string extension) => NetworkUtility.Mime(extension);

        #endregion

        #region 开放方法

        /// <summary>响应重定向。</summary>
        protected virtual void RespondRedirect(string urlPath, string location) => Response.Model = new ApiRedirectModel(location);

        /// <summary>响应 400 状态。</summary>
        /// <remarks>默认：设置状态为 400，不输出内容。</remarks>
        protected virtual void Respond400(string path, string reason) => Response.Model = new ApiStatusModel(400);

        /// <summary>响应 404 状态。</summary>
        /// <remarks>默认：设置状态为 404，不输出内容。</remarks>
        protected virtual void Respond404(string urlPath) => Response.Model = new ApiStatusModel(404);

        /// <summary>响应 403 状态。</summary>
        /// <remarks>默认：设置状态为 403，不输出内容。</remarks>
        protected virtual void Respond403(string urlPath) => Response.Model = new ApiStatusModel(403);

        #endregion

        #region 内置的执行程序

        const bool WipeBom = true;

        // 默认文档的文件名
        static string[] DefaultFileNames = new string[] { "index.html", "index.htm", "default.html", "default.htm" };

        // 文件名中不允许出现的字符
        static char[] InvalidFileNameChars = Path.GetInvalidFileNameChars();

        // Zip 文件的缓存
        static Dictionary<Type, Dictionary<string, byte[]>> WebZips = new Dictionary<Type, Dictionary<string, byte[]>>();

        // 解析 URL 的路径，获取本地路径。
        string MapPath(string urlPath)
        {
            var path = GetRoot();
            if (path.IsEmpty()) return "";
            if (string.IsNullOrEmpty(urlPath)) return path;

            foreach (var split in urlPath.Split('/', '\\'))
            {
                var segment = split.ToTrim();
                if (segment == null || segment == "" || segment == "." || segment == "..") continue;
                path = StorageUtility.CombinePath(path, segment);
            }
            return path;
        }

        void InternalExecute(string urlPath)
        {
            if (urlPath.IsEmpty())
            {
                Respond400(urlPath, "请求的 URL 路径无效。");
                return;
            }

            // 检查路径
            var urlIsDir = urlPath.EndsWith("/") || urlPath.EndsWith("\\");
            var urlExt = null as string;
            var urlIsHtml = false;
            var segments = new List<string>();
            {
                var split = urlPath == null ? new string[0] : urlPath.Split('/', '\\');
                segments.Capacity = split.Length;
                foreach (var item in split)
                {
                    var segment = TextUtility.DecodeUrl(item).Trim();
                    if (string.IsNullOrEmpty(segment)) continue;
                    if (segment == "." || segment == "..") continue;

                    // 检查无效字符
                    foreach (var c in segment)
                    {
                        if (Array.IndexOf(InvalidFileNameChars, c) > -1)
                        {
                            Respond400(urlPath, $"请求的路径中含有无效字符。");
                            return;
                        }
                    }

                    segments.Add(segment);
                }

                // 重置 UrlPath
                urlPath = "/" + segments.Join("/");
                if (segments.Count > 0)
                {
                    // 请求筛选
                    if (IsBlocked(segments[0]))
                    {
                        Respond404(urlPath);
                        return;
                    }

                    urlExt = segments[segments.Count - 1].ToLower().Split('.').Last();
                    urlIsHtml = urlExt == "html" || urlExt == "htm" || urlExt == "shtml";
                }
            }

            // 本地存储路径
            var storagePath = MapPath(urlPath);

            // 本地文件
            if (StorageUtility.FileExists(storagePath))
            {
                ExecuteFile(storagePath, urlPath, urlExt, urlIsHtml);
                return;
            }

            // 目录
            if (StorageUtility.DirectoryExists(storagePath))
            {
                var filePath = SearchDefaultFile(storagePath);
                if (!string.IsNullOrEmpty(filePath))
                {
                    if (urlIsDir)
                    {
                        ExecuteFile(filePath, urlPath, urlExt, urlIsHtml);
                        return;
                    }
                    else
                    {
                        var location = urlPath + "/";
                        RespondRedirect(urlPath, location);
                        return;
                    }
                }
            }

            // WebZip
            var webZip = GetWebZip();
            if (webZip != null)
            {
                // 文件
                {
                    if (webZip.TryGetValue(urlPath, out var data))
                    {
                        ExecuteFile(data, urlExt, urlIsHtml);
                        return;
                    }
                }

                // 尝试匹配默认文档
                foreach (var defaultName in DefaultFileNames)
                {
                    var defaultPath = TextUtility.AssureEnds(urlPath, "/") + defaultName;
                    if (webZip.TryGetValue(defaultPath, out var data))
                    {
                        if (urlIsDir)
                        {
                            ExecuteFile(data, defaultName, true);
                        }
                        else
                        {
                            var location = TextUtility.AssureEnds(urlPath, "/");
                            RespondRedirect(urlPath, location);
                        }
                        return;
                    }
                }
            }

            // 未知
            Respond404(urlPath);
        }

        void ExecuteFile(string storagePath, string urlPath, string urlExt, bool urlIsHtml)
        {
            var contentType = ContentType(urlExt);
            if (urlIsHtml)
            {
                var text = ReadTextFile(urlPath, 0);
                var model = new ApiTextModel(text, contentType);
                Response.Model = model;
            }
            else
            {
                try
                {
                    var stream = StorageUtility.OpenFile(storagePath, true);
                    var model = new ApiStreamModel();
                    model.ContentType = contentType;
                    model.AutoDispose = true;
                    model.Stream = stream;
                    Response.Model = model;
                }
                catch (Exception ex)
                {
                    Respond400(storagePath, $"<{ex.GetType().Name}> {ex.Message}");
                }
            }
        }

        void ExecuteFile(byte[] data, string urlExt, bool urlIsHtml)
        {
            var contentType = ContentType(urlExt);
            if (urlIsHtml)
            {
                var text = data.Text();
                text = ServerSideIncludes(text, 0);
                var model = new ApiTextModel(text, contentType);
                Response.Model = model;
            }
            else
            {
                var model = new ApiBytesModel(data, contentType);
                Response.Model = model;
            }
        }

        /// <summary>读取文本文件。</summary>
        string ReadTextFile(string urlPath, int recursive)
        {
            // 主文件保留原有的 BOM
            var wipeBom = recursive > 0;

            // 本地文件
            var path = MapPath(urlPath);
            if (StorageUtility.FileExists(path))
            {
                var data = StorageUtility.ReadFile(path, wipeBom);
                var text = data.Text();
                text = ServerSideIncludes(text, recursive);
                return text;
            }

            // Zip
            var webZip = GetWebZip();
            if (webZip != null)
            {
                if (webZip.TryGetValue(urlPath, out var data))
                {
                    var text = data.Text();
                    text = ServerSideIncludes(text, recursive);
                    return text;
                }
            }

            // 文件不存在
            return null;
        }

        /// <summary>在指定目录下搜索默认文件。</summary>
        /// <returns>完整文件路径，当搜索失败时返回 NULL。</returns>
        string SearchDefaultFile(string directoryPath)
        {
            // 获取子文件路径
            var filePaths = StorageUtility.GetSubFiles(directoryPath);
            if (filePaths.Count < 0) return null;
            filePaths.Sort();

            // 获取文件名
            var dict = new Dictionary<string, string>(filePaths.Count);
            foreach (var filePath in filePaths)
            {
                var name = Path.GetFileName(filePath).ToLower();
                if (dict.ContainsKey(name)) continue;
                dict.Add(name, filePath);
            }

            // 按顺序获取
            foreach (var defaultFileName in DefaultFileNames)
            {
                if (dict.TryGetValue("index.html", out var physicalPath))
                {
                    return physicalPath;
                }
            }

            return null;
        }

        Dictionary<string, byte[]> GetWebZip()
        {
            var instanceType = GetType();
            lock (WebZips)
            {
                if (WebZips.TryGetValue(instanceType, out var webZip))
                {
                    return webZip;
                }
                else
                {
                    var dict = LoadWebZip();
                    if (dict != null)
                    {
                        var temp = new Dictionary<string, byte[]>(dict.Count);
                        foreach (var kvp in dict)
                        {
                            if (kvp.Key.IsEmpty()) continue;
                            var url = string.Join("/", kvp.Key.Split('/', '\\'));
                            url = "/" + url.ToLower();
                            if (temp.ContainsKey(url)) continue;
                            temp.Add(url, kvp.Value);
                        }
                        dict = temp;
                    }
                    WebZips.Add(instanceType, dict);
                }
            }
            return null;
        }

        string ServerSideIncludes(string text, int recursive)
        {
            if (!AllowSSI) return text;
            if (recursive > 10) return text;
            if (string.IsNullOrEmpty(text)) return "";

            // 按首尾截取。
            const string left = "<!--";
            const string right = "-->";
            const string head = "#include virtual=";
            var sb = new StringBuilder();
            while (true)
            {
                var offset = text.IndexOf(left);
                if (offset < 0)
                {
                    sb.Append(text);
                    break;
                }
                if (offset > 0)
                {
                    sb.Append(text.Substring(0, offset));
                    text = text.Substring(offset + left.Length);
                }
                else text = text.Substring(left.Length);
                var length = text.IndexOf(right);
                if (length < 1)
                {
                    sb.Append(left);
                    sb.Append(text);
                    break;
                }
                var inner = text.Substring(0, length);
                var temp = inner.ToTrim();
                if (temp.StartsWith(head))
                {
                    temp = temp.Substring(head.Length);
                    temp = temp.Replace("\"", "");

                    var includeText = ReadTextFile(temp, recursive + 1);
                    if (includeText != null && includeText.Length > 0) sb.Append(includeText);
                }
                else
                {
                    sb.Append(left);
                    sb.Append(inner);
                    sb.Append(right);
                }
                text = text.Substring(length + right.Length);
            }

            var output = sb.ToString();
            return output;
        }

        #endregion

        #region private

        /// <summary>列出指定目录的子项。</summary>
        Json ListChildren(string directory)
        {
            if (!System.IO.Directory.Exists(directory)) return null;
            var json = Json.NewObject();
            json.SetProperty("directories", ListDirectories(directory));
            json.SetProperty("files", ListFiles(directory));
            return json;
        }

        Json ListDirectories(string directory)
        {
            var array = Json.NewArray();
            var subs = StorageUtility.GetSubDirectories(directory);
            subs.Sort();
            foreach (var sub in subs)
            {
                var split = sub.Split('/', '\\');
                var name = split[split.Length - 1];
                if (IsBlocked(name)) continue;

                var json = Json.NewObject();
                json.SetProperty("name", name);
                try
                {
                    var info = new DirectoryInfo(sub);
                    json.SetProperty("modified", info.LastWriteTimeUtc.Stamp());
                }
                catch { }
                array.AddItem(json);
            }
            return array;
        }

        Json ListFiles(string directory)
        {
            var array = Json.NewArray();
            var subs = StorageUtility.GetSubFiles(directory);
            subs.Sort();
            foreach (var sub in subs)
            {
                var name = Path.GetFileName(sub);
                if (IsBlocked(name)) continue;

                var json = Json.NewObject();
                json.SetProperty("name", name);
                try
                {
                    var info = new FileInfo(sub);
                    json.SetProperty("size", info.Length);
                    json.SetProperty("modified", info.LastWriteTimeUtc.Stamp());
                }
                catch { }
                array.AddItem(json);
            }
            return array;
        }

        /// <summary>请求筛选：检查段内容是要被屏蔽。</summary>
        bool IsBlocked(string segment)
        {
            if (string.IsNullOrEmpty(segment)) return true;
            var lower = segment.ToLower();
            switch (lower)
            {
                case ".":
                case "..":

                // Synology
                case "@eadir":
                case "#recycle":

                // Windows
                case "$recycle.bin":
                case "recycler":
                case "system volume information":
                case "desktop.ini":
                case "thumbs.db":

                // macOS
                case ".ds_store":
                case ".localized":

                // IIS
                case "app_code":
                case "app_data":
                case "aspnet_client":
                case "bin":
                case "web.config":

                    return true;
            }
            return false;
        }

        #endregion

    }

}