apewer-dotnet/Apewer/Web/WebUtility.cs

using Apewer;
using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using Apewer.Models;
using System.IO;

#if NETFX
using System.Web;
#endif

#if NETCORE
using Microsoft.AspNetCore.Http;
#endif

namespace Apewer.Web
{

    /// <summary></summary>
    public static class WebUtility
    {

        #region url

        /// <summary>按 & 拆分多个参数。</summary>
        public static StringPairs ParseParameters(string query, bool decode = true)
        {
            var input = query;
            var list = new StringPairs();
            if (!string.IsNullOrEmpty(input))
            {
                if (input[0] == '?') input = input.Substring(1);
                var args = input.Split('&');
                foreach (var arg in args)
                {
                    var equals = arg.IndexOf("=");
                    var left = equals < 0 ? arg : arg.Substring(0, equals);
                    var right = equals < 0 ? "" : arg.Substring(equals + 1);
                    if (decode)
                    {
                        left = TextUtility.DecodeUrl(left);
                        right = TextUtility.DecodeUrl(right);
                    }
                    list.Add(left, right);
                }
            }
            return list;
        }

        /// <summary>获取 URL 查询段，不存在的段为 NULL 值。可要求解码。</summary>
        public static string GetSegmental(Uri url, int index = 3, bool decode = false)
        {
            try
            {
                if (url == null) return null;
                if (index < 0) return null;
                var sus = url.AbsolutePath.Split('/');
                if (sus.Length > index)
                {
                    var result = sus[index];
                    if (decode) result = TextUtility.DecodeUrl(result);
                    return result;
                }
            }
            catch { }
            return null;
        }

        /// <summary>获取参数并解码。</summary>
        public static string GetParameter(string encoded, params string[] names)
        {
            if (string.IsNullOrEmpty(encoded)) return null;
            if (names == null || names.Length < 1) return null;

            // Names 转为小写，加强适配。
            var lowerNames = new List<string>();
            foreach (var name in names)
            {
                var lower = TextUtility.ToLower(name);
                if (string.IsNullOrEmpty(lower)) continue;
                lowerNames.Add(lower);
            }
            if (lowerNames.Count < 1) return null;

            // 分参数对比。
            var parameters = ParseParameters(encoded);
            var matched = false;
            foreach (var parameter in parameters)
            {
                var left = parameter.Key;
                var right = parameter.Value;
                var lowerLeft = TextUtility.ToLower(left);
                if (lowerNames.Contains(right))
                {
                    matched = true;
                    if (!string.IsNullOrEmpty(right)) return right;
                }
            }

            return matched ? "" : null;
        }

        /// <summary>指定可能的参数名，从 URL 中获取参数值并解码。</summary>
        public static string GetParameter(Uri url, params string[] names)
        {
            return url == null ? null : GetParameter(url.Query, names);
        }

        #endregion

#if NETFX || NETCORE

        #region http 

        /// <summary>获取直连端的 IP。</summary>
        public static string GetDirectIP(ApiRequest request)
        {
            if (request == null) return null;
            if (request.Context == null) return null;
            return GetDirectIP(request.Context.Request);
        }

        /// <summary>获取直连端的 IP。</summary>
        public static string GetDirectIP(HttpRequest request)
        {
            if (request == null) return null;
#if NETFX
            return request.UserHostAddress;
#else
            if (request.HttpContext == null || request.HttpContext.Connection == null) return null;
            return request.HttpContext.Connection.RemoteIpAddress.ToString();
#endif
        }

        /// <summary>获取客户端 IP。</summary>
        public static string GetClientIP(ApiRequest request, bool withProxy = false)
        {
            if (request == null) return null;
            if (request.Context == null) return null;
            return GetClientIP(request.Context.Request, withProxy);
        }

        /// <summary>获取客户端 IP。</summary>
#if NETFX
        public static string GetClientIP(System.Web.HttpRequest request, bool withProxy = false)
#else
        public static string GetClientIP(Microsoft.AspNetCore.Http.HttpRequest request, bool withProxy = false)
#endif
        {
            if (request == null) return null;
            var d = GetDirectIP(request);
            var f = GetForwardedIP(request);

            // return string.IsNullOrEmpty(f) ? "NULL" : $"{f},NULL";
            // return string.IsNullOrEmpty(f) ? $"{d}" : $"{f},{d}";

            // 没有代理，返回 Direct IP。
            if (string.IsNullOrEmpty(f)) return d;

            // 有代理，先加入 Forwarded IP，再加入 Direct IP。
            var ip = f;
            if (withProxy && !string.IsNullOrEmpty(d)) ip = ip + "," + d;

            return ip;
        }

        /// <summary>请求来自于可信客户端。</summary>
        public static bool FromTrusted(HttpRequest request, params string[] addresses)
        {
            if (request == null) return false;

            // 解析可信地址。
            var ips = new List<string>();
            if (addresses != null)
            {
                foreach (var address in addresses)
                {
                    var ip = address;
                    if (!NetworkUtility.IsIP(ip)) ip = NetworkUtility.Resolve(ip);
                    if (!NetworkUtility.IsIP(ip)) continue;
                    if (ips.Contains(ip)) continue;
                    ips.Add(ip);
                }
            }

            // 检测代理 IP。
            var headers = GetHeaders(request);
            var proxyIP = headers.GetValue("Ali-CDN-Real-IP", true).SafeTrim();
            if (proxyIP.NotEmpty())
            {
                var split = proxyIP.Split(' ', '|', ',', ':');
                proxyIP = split.Length > 0 ? split[0] : null;
            }
            if (proxyIP.IsEmpty())
            {
                proxyIP = headers.GetValue("X-Forwarded-For", true).SafeTrim();
                if (proxyIP.NotEmpty())
                {
                    var split = proxyIP.Split(' ', '|', ',', ':');
                    proxyIP = split.Length > 0 ? split[0] : null;
                }
            }
            if (proxyIP.NotEmpty() && ips.Contains(proxyIP)) return true;

            // 检测直连 IP，
            var directIP = GetDirectIP(request);
            if (NetworkUtility.IsIP(directIP))
            {
                if (proxyIP.IsEmpty())
                {
                    if (NetworkUtility.FromLAN(directIP)) return true;
                    if (ips.Contains(directIP)) return true;
                }
                else
                {
                    if (NetworkUtility.FromLAN(proxyIP) && NetworkUtility.FromLAN(directIP)) return true;
                }

            }

            return false;
        }

        /// <summary>请求来自于可信客户端。</summary>
        public static bool FromTrusted(HttpContext context, params string[] addresses)
        {
            if (context == null) return false;
            return FromTrusted(context.Request, addresses);
        }

        /// <summary>请求来自于可信客户端。</summary>
        public static bool FromTrusted(ApiRequest request, params string[] addresses)
        {
            if (request == null) return false;
            return FromTrusted(request.Context, addresses);
        }

        /// <summary>获取 HTTP 方法。</summary>
        public static Network.HttpMethod GetMethod(string method)
        {
            if (!string.IsNullOrEmpty(method))
            {
                var upper = TextUtility.ToUpper(method);
                if (upper.Contains("OPTIONS")) return Network.HttpMethod.OPTIONS;
                else if (upper.Contains("POST")) return Network.HttpMethod.POST;
                else if (upper.Contains("GET")) return Network.HttpMethod.GET;
                else if (upper.Contains("CONNECT")) return Network.HttpMethod.CONNECT;
                else if (upper.Contains("DELETE")) return Network.HttpMethod.DELETE;
                else if (upper.Contains("HEAD")) return Network.HttpMethod.HEAD;
                else if (upper.Contains("PATCH")) return Network.HttpMethod.PATCH;
                else if (upper.Contains("PUT")) return Network.HttpMethod.PUT;
                else if (upper.Contains("TRACE")) return Network.HttpMethod.TRACE;
            }
            return Network.HttpMethod.NULL;
        }

        /// <summary>获取 HTTP 方法。</summary>
        public static Network.HttpMethod GetMethod(HttpRequest request)
        {
            if (request == null) return Network.HttpMethod.NULL;
#if NETFX
            return GetMethod(request.HttpMethod);
#else
            return GetMethod(request.Method);
#endif
        }

        #endregion

        #region request 

        /// <summary>获取请求的 URL，失败时返回 NULL 值。</summary>
        public static Uri GetUrl(HttpRequest request)
        {
            if (request == null) return null;
#if NETFX
            return request.Url;
#else
            var context = request.HttpContext;
            if (context == null) return null;

            var https = request.IsHttps;
            var port = context.Connection.LocalPort;
            var query = request.QueryString == null ? null : request.QueryString.Value;

            var sb = new StringBuilder();
            sb.Append(https ? "https://" : "http://");
            sb.Append(request.Host.Host ?? "");
            if ((https && port != 443) || (!https && port != 80))
            {
                sb.Append(":");
                sb.Append(port);
            }
            sb.Append(request.Path);
            if (!string.IsNullOrEmpty(query))
            {
                sb.Append("?");
                sb.Append(query);
            }

            var url = sb.ToString();
            var uri = new Uri(url);
            return uri;
#endif
        }

        /// <summary>获取 HTTP 头。</summary>
        public static StringPairs GetHeaders(HttpRequest request)
        {
            var sp = new StringPairs();
            if (request != null && request.Headers != null)
            {
#if NETFX
                foreach (var key in request.Headers.AllKeys)
#else
                foreach (var key in request.Headers.Keys)
#endif
                {
                    var value = request.Headers[key].ToString();
                    sp.Add(new KeyValuePair<string, string>(key, value));
                }
            }
            return sp;
        }

        /// <summary>获取 X-Forwarded-For。</summary>
        public static string GetForwardedIP(StringPairs headers)
        {
            if (headers == null) return null;
            var value = headers.GetValue("x-forwarded-for");
            if (!string.IsNullOrEmpty(value)) value = value.Split(":")[0];
            return value;
        }

        /// <summary>获取 X-Forwarded-For。</summary>
        public static string GetForwardedIP(ApiRequest request)
        {
            if (request == null) return null;
            return GetForwardedIP(request.Headers);
        }

        /// <summary>获取 X-Forwarded-For。</summary>
        public static string GetForwardedIP(HttpRequest request) => GetForwardedIP(GetHeaders(request));

        /// <summary>获取 User Agent。</summary>
        public static string GetUserAgent(StringPairs headers)
        {
            if (headers == null) return null;
            return headers.GetValue("user-agent");
        }

        /// <summary>获取 User Agent。</summary>
        public static string GetUserAgent(HttpRequest request) => GetUserAgent(GetHeaders(request));

        #endregion

        #region response

        /// <summary>发送 302 状态，将客户端重新定向到新 URL。</summary>
        public static void RedirectResponse(HttpResponse response, string url)
        {
            if (response == null) return;
            try { response.Redirect(url, true); } catch { }
        }

        /// <summary>停止并关闭响应流。可指定向发送缓冲区的数据。</summary>
        public static void StopResponse(HttpResponse response, bool flush = true)
        {
            if (response == null) return;
#if NETFX
            try { if (flush) response.Flush(); } catch { }
            try { response.Close(); } catch { }
            // try { response.End(); } catch { }
#endif
        }

        #endregion

        #region api

        /// <summary>获取 URL 查询段，不存在的段为 NULL 值。可要求解码。</summary>
        public static string GetSegmentalUrl(ApiRequest request, int index = 3, bool decode = false)
        {
            return request == null ? null : GetSegmental(request.Url, index, decode);
        }

        /// <summary>获取参数。</summary>
        public static string GetParameter(List<KeyValuePair<string, string>> parameters, params string[] names)
        {
            if (parameters == null || parameters.Count < 1) return null;
            if (names == null || names.Length < 1) return null;

            var lowerNames = new List<string>();
            foreach (var name in names)
            {
                var lower = TextUtility.ToLower(name);
                if (string.IsNullOrEmpty(lower)) continue;
                lowerNames.Add(lower);
            }

            foreach (var parameter in parameters)
            {
                var lowerKey = TextUtility.ToLower(parameter.Key);
                if (lowerNames.Contains(lowerKey))
                {
                    var value = parameter.Value;
                    if (!string.IsNullOrEmpty(value)) return value;
                }
            }
            return null;
        }

        /// <summary>获取参数，指定可能的参数名，从 URL 中获取参数时将解码。</summary>
        public static string GetParameter(ApiRequest request, params string[] names)
        {
            if (request == null) return null;
            if (names == null || names.Length < 1) return null;

            var sameNames = new List<string>();
            var lowerNames = new List<string>();
            foreach (var name in names)
            {
                if (string.IsNullOrEmpty(name)) continue;
                if (!sameNames.Contains(name)) sameNames.Add(name);

                var lower = TextUtility.ToLower(name);
                if (string.IsNullOrEmpty(lower)) continue;
                if (!lowerNames.Contains(lower)) lowerNames.Add(lower);
            }

            // POST 优先。
            var data = request.Data;
            if (data != null && data.IsObject)
            {
                var properties = data.GetProperties();
                if (properties != null)
                {
                    // Json 区分大小写，先全字匹配。
                    foreach (var property in properties)
                    {
                        if (!property.IsProperty) continue;
                        if (sameNames.Contains(property.Name) && property.Value != null)
                        {
                            var value = property.Value;
                            if (value == null) continue;
                            var text = value.ToString();
                            if (!string.IsNullOrEmpty(text)) return text;
                        }
                    }

                    // 以小写模糊匹配。
                    foreach (var property in properties)
                    {
                        if (!property.IsProperty) continue;
                        var lowerName = TextUtility.ToLower(property.Name);
                        if (lowerNames.Contains(lowerName) && property.Value != null)
                        {
                            var value = property.Value;
                            if (value == null) continue;
                            var text = value.ToString();
                            if (!string.IsNullOrEmpty(text)) return text;
                        }
                    }
                }
            }

            // 从已解析的 Parameters 中搜索。
            if (request.Parameters != null)
            {
                var value = GetParameter(request.Parameters);
                if (!string.IsNullOrEmpty(value)) return value;
            }

            // GET 参数。
            if (request.Parameters != null)
            {
                // 全字匹配。
                foreach (var kvp in request.Parameters)
                {
                    if (string.IsNullOrEmpty(kvp.Key) || string.IsNullOrEmpty(kvp.Value)) continue;
                    if (sameNames.Contains(kvp.Key)) return kvp.Value;
                }

                // 以小写模糊匹配。
                foreach (var kvp in request.Parameters)
                {
                    var lowerKey = TextUtility.ToLower(kvp.Key);
                    if (string.IsNullOrEmpty(lowerKey) || string.IsNullOrEmpty(kvp.Value)) continue;
                    if (lowerNames.Contains(lowerKey)) return kvp.Value;
                }
            }

            return null;
        }

        /// <summary>转移 WebAPI 请求到其它服务器、应用或功能。</summary>
        public static string Transfer(ApiController controller, string url, string application = null, string function = null)
        {
            if (controller == null || controller.Request == null || controller.Response == null) return "ApiControllser 无效。";
            if (url.IsEmpty()) return "ApiControllser 无效。";

            var s = Json.NewObject();
            s.SetProperty("random", TextUtility.NewGuid());
            s.SetProperty("application", application.IsEmpty() ? controller.Request.Application : application);
            s.SetProperty("function", function.IsEmpty() ? controller.Request.Function : function);
            s.SetProperty("data", controller.Request.Data);
            s.SetProperty("session", controller.Request.Session);
            s.SetProperty("ticket", controller.Request.Ticket);
            s.SetProperty("page", controller.Request.Page);

            var c = Network.HttpClient.SimplePost(url, s.ToString().GetBytes());
            var r = Json.Parse(c.Response.Data.GetString());

            if (r == null || !r.Available)
            {
                controller.Response.Error("请求失败。");
                return "请求失败。";
            }

            if (r["status"] != "ok")
            {
                controller.Response.Error(r["message"]);
                return r["message"];
            }

            controller.Response.Data.Reset(r.GetProperty("data"));
            return null;
        }

        #endregion

        #region Log

        private static object LogLocker = new object();

        /// <summary>获取日志文件路径发生错误时返回 NULL 值。</summary>
        /// <remarks>d:\app\log\2020-02-02.log</remarks>
        /// <remarks>d:\www\app_data\log\2020-02-02.log</remarks>
        public static string GetLogPath()
        {
            // 找到 App_Data 目录。
            var appDir = KernelUtility.ApplicationBasePath;
            var dataDir = Path.Combine(appDir, "app_data");
            if (StorageUtility.DirectoryExists(dataDir)) appDir = dataDir;

            // 检查 Log 目录，不存在时创建，创建失败时返回。
            var logDir = Path.Combine(appDir, "log");
            if (!StorageUtility.AssureDirectory(logDir)) return null;

            // 文件不存在时创建新文件，无法创建时返回。
            var date = DateTime.Now.ToLucid(true, false, false, false);
            var filePath = Path.Combine(logDir, date + ".log");
            StorageUtility.CreateFile(filePath, 0, false);
            if (!StorageUtility.FileExists(filePath)) return null;

            // 返回 log 文件路径。
            return filePath;
        }

        /// <summary>写入日志。</summary>
        public static string WriteLog(params object[] content)
        {
            lock (LogLocker)
            {
                var path = GetLogPath();
                if (path.IsEmpty()) return "无法获取日志文件路径。";

                var text = TextUtility.Join(" | ", content);
                text = TextUtility.Merge(DateTimeUtility.NowLucid, "  ", text, "\r\n");

                var bytes = TextUtility.ToBinary(text);
                if (!StorageUtility.AppendFile(path, bytes)) return "写日志文件失败。";

                return null;
            }
        }

        #endregion

#endif

    }

}