using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Security;
using System.Web;
using System.Security.Principal;
using System.Configuration;
using System.Reflection;

namespace Bowin.Common
{
    public class FormsAuthenticationHelper
    {
        /// <summary>
        /// 创建登陆票据和存cookie
        /// 用于登陆成功后标记已登陆和用户信息
        /// </summary>
        /// <param name="httpContext">当前httpContext</param>
        /// <param name="cookieName">系统cookie名字</param>
        /// <param name="luserData">用户信息和CustomPrincipal对应</param>
        /// <returns></returns>
        public bool loginFormsAuthentication(HttpContextBase httpContext, string cookieName, List<string> luserData)
        {
            bool result = false;

            try
            {
                FormsAuthenticationTicket authTicket;
                authTicket = new FormsAuthenticationTicket(
                    1,  //version
                    luserData[0],  //loginID
                    DateTime.Now, //  creation
                    DateTime.Now.Add(FormsAuthentication.Timeout),//expired time
                    false, //Persistent
                    string.Join("|", luserData));
                //加密authTicket
                string data = FormsAuthentication.Encrypt(authTicket);

                HttpCookie cookies = new HttpCookie(cookieName, data);

                cookies.Domain = FormsAuthentication.CookieDomain;
                cookies.Secure = false;
                cookies.Path = FormsAuthentication.FormsCookiePath;
                cookies.Expires = authTicket.Expiration;
                httpContext.Response.Cookies.Add(cookies);
                result = true;
            }
            catch (Exception ex)
            {
                result = false;
            }

            return result;
        }

        /// <summary>
        /// 在Global.asax的Application_AuthenticateRequest事件使用
        /// 把客户端cockie解密存放于Page.User.(CustomPrincipal)对象
        /// </summary>
        /// <param name="httpContext">当前httpContext</param>
        /// <param name="cookieName">系统cookie名字</param>
        /// <param name="l_unvalidateUrl">排除掉需要验证登陆的url关健词</param>
        /// <param name="l_validateUrl">必须要验证登陆的url关健词</param>
        public void AuthenticateRequest(HttpContext httpContext, string cookieName, List<string> l_unvalidateUrl, List<string> l_validateUrl = null)
        {
            HttpCookie authCookie = httpContext.Request.Cookies[cookieName];

            if (authCookie == null)
            {
                string rurl = httpContext.Request.Path.ToLower();

                l_unvalidateUrl.Add(FormsAuthentication.LoginUrl.TrimStart('~'));

                if ((l_validateUrl != null && l_validateUrl.Any(w => rurl.IndexOf(w.ToLower()) >= 0)) 
                    || !l_unvalidateUrl.Where(w => rurl.IndexOf(w.ToLower()) >= 0).Any())
                {
                    httpContext.Response.Redirect(FormsAuthentication.LoginUrl + "?targetUrl=" + httpContext.Server.UrlEncode(httpContext.Request.Url.AbsoluteUri));
                }
                return;
            }

            FormsAuthenticationTicket authTicket = null;   //票椐
            try
            {
                authTicket = System.Web.Security.FormsAuthentication.Decrypt(authCookie.Value); // Cookie 解密
            }
            catch (Exception ex)
            {
                //cookie解密报错清除
                authCookie.Expires = DateTime.Now.AddDays(-1);
                httpContext.Response.Cookies.Add(authCookie);
                httpContext.Response.Redirect(FormsAuthentication.LoginUrl);
                return;
            }

            string UserName = authTicket.UserData;  //分解存在Cookie内的用户信息--
            FormsIdentity id = new FormsIdentity(authTicket);
            ICustomPrincipal principal = CustomPrincipalFactory.Create(id, UserName);
            httpContext.User = principal;
        }

        public void GetTicket(HttpContext httpContext, string url)
        {
            try
            {
                System.Web.Security.FormsAuthenticationTicket tk = ((System.Web.Security.FormsIdentity)httpContext.User.Identity).Ticket;

                string key = System.Web.Security.FormsAuthentication.Encrypt(tk); //每次加密后的字串都是不同的

                httpContext.Response.Redirect(url + "?ssologin=1&ticket=" + key); //跳转至下一页面
            }
            catch
            {
                httpContext.Response.Redirect(url + "?ssologin=0"); //跳转至下一页面
            }
            finally
            {
                httpContext.Response.End();
            }
        }

        public ICustomPrincipal ValidateTitcket(HttpContext httpContext, string ticket)
        {
            FormsAuthenticationTicket authTicket = null;   //票椐
            try
            {
                authTicket = System.Web.Security.FormsAuthentication.Decrypt(ticket); // Cookie 解密
            }
            catch (Exception ex)
            {
                return null;
            }

            string UserName = authTicket.UserData;  //分解存在Cookie内的用户信息--
            FormsIdentity id = new FormsIdentity(authTicket);
            ICustomPrincipal principal = CustomPrincipalFactory.Create(id, UserName);
            return principal;
        }
    }

    public interface ICustomPrincipal : IPrincipal
    {
        Guid UserID { get; set; }
        string LoginID { get; set; }
        string Name { get; set; }

        void ProcessData(IIdentity id, string data);
    }

    public class CustomPrincipalFactory
    {
        public static ICustomPrincipal Create(IIdentity id, string data)
        {
            string assemblyName = ConfigurationManager.AppSettings["CustomPrincipanAssembly"];
            string className = ConfigurationManager.AppSettings["CustomPrincipanClass"];

            Assembly assembly = Assembly.Load(assemblyName);
            ICustomPrincipal principal = (ICustomPrincipal)assembly.CreateInstance(className);

            principal.ProcessData(id, data);

            return principal;
        }
    }
}