using System;
using System.Text;
using System.Web;
using System.Web.UI;
using NewLife.Log;
using NewLife.Model;

namespace NewLife.Web
{
    /// <summary>JavaScript脚本。提供Js的基本操作，同时也支持继承扩展</summary>
    /// <remarks>
    /// 提供静态成员<see cref="Current"/>，以及常用的<see cref="WriteScript"/>和<see cref="Alert"/>
    /// </remarks>
    public class Js : IJs
    {
        #region 通用静态
        /// <summary>当前实现</summary>
        public static IJs Current { get; set; }

        static Js()
        {
            Current = ObjectContainer.Current.AutoRegister<IJs, Js>().Resolve<IJs>();

            if (Current == null)
                Current = new Js();
            else if (XTrace.Debug && Current.GetType() != typeof(Js))
                XTrace.WriteLine("Js提供者：{0}", Current.GetType());
        }

        /// <summary>Js脚本编码</summary>
        /// <param name="str"></param>
        /// <returns></returns>
        public static String Encode(String str)
        {
            if (String.IsNullOrEmpty(str)) return null;

            str = str.Replace(@"\", @"\\");
            str = str.Replace("'", @"\'");
            str = str.Replace(Environment.NewLine, @"\n");
            str = str.Replace("\r", @"\n");
            str = str.Replace("\n", @"\n");

            return str;
        }

        /// <summary>输出脚本</summary>
        /// <param name="script"></param>
        /// <param name="addScriptTags"></param>
        /// <returns></returns>
        public static IJs WriteScript(String script, Boolean addScriptTags = true)
        {
            return Current.WriteScript(script, addScriptTags);
        }

        /// <summary>弹出页面提示</summary>
        /// <param name="message">消息内容</param>
        /// <param name="title">标题</param>
        /// <param name="delaySecond">延迟指定秒数以后自动关闭，默认0表示不关闭</param>
        /// <param name="kind">种类，info/success/error等</param>
        /// <returns></returns>
        public static IJs Alert(String message, String title = null, Int32 delaySecond = 0, String kind = null)
        {
            if (String.IsNullOrEmpty(message)) return Current;

            return Current.Alert(message, title, delaySecond, kind);
        }
        #endregion

        #region 成员
        /// <summary>输出脚本</summary>
        /// <param name="script"></param>
        /// <param name="addScriptTags"></param>
        /// <returns></returns>
        IJs IJs.WriteScript(String script, Boolean addScriptTags)
        {
            OnWriteScript(script, addScriptTags);
            return this;
        }

        /// <summary>输出脚本</summary>
        /// <param name="script"></param>
        /// <param name="addScriptTags"></param>
        /// <returns></returns>
        protected virtual void OnWriteScript(String script, Boolean addScriptTags)
        {
            if (HttpContext.Current.Handler is Page page && page.ClientScript != null)
                page.ClientScript.RegisterStartupScript(page.GetType(), script, script, addScriptTags);
            else
            {
                var format = "{0}";
                if (addScriptTags) format = "<script>{0}</script>";
                HttpContext.Current.Response.Write(format.F(script));
            }
        }

        /// <summary>弹出页面提示</summary>
        /// <param name="message">消息内容</param>
        /// <param name="title">标题</param>
        /// <param name="msDelay">延迟指定毫秒数以后自动关闭，默认0表示不关闭</param>
        /// <param name="kind">种类，info/success/error等</param>
        /// <returns></returns>
        IJs IJs.Alert(String message, String title, Int32 msDelay, String kind)
        {
            if (String.IsNullOrEmpty(message)) return this;

            OnAlert(message, title, msDelay, kind);

            return this;
        }

        /// <summary>弹出页面提示</summary>
        /// <param name="message">消息内容</param>
        /// <param name="title">标题</param>
        /// <param name="msDelay">延迟指定毫秒数以后自动关闭，默认0表示不关闭</param>
        /// <param name="kind">种类，info/success/error等</param>
        /// <returns></returns>
        protected virtual void OnAlert(String message, String title, Int32 msDelay, String kind)
        {
            WriteScript("alert('" + Encode(message) + "');", true);
        }

        /// <summary>停止输出</summary>
        public virtual IJs End()
        {
            //HttpContext.Current.Response.End();
            // http://www.newlifex.com/showtopic-1106.aspx
            // 用End引发异常
            var Response = HttpContext.Current.Response;
            // 设置编码，避免乱码，关键是Charset
            Response.ContentEncoding = Encoding.UTF8;
            Response.Charset = Encoding.UTF8.WebName;
            Response.Flush();
            HttpContext.Current.ApplicationInstance.CompleteRequest();
            return this;
        }

        /// <summary>后退一步</summary>
        public virtual IJs Back() { return WriteScript("history.go(-1);"); }

        /// <summary>刷新该页面</summary>
        public virtual IJs Refresh() { return WriteScript("location.href = location.href;"); }

        /// <summary>重定向到另外的页面</summary>
        /// <param name="url"></param>
        public virtual IJs Redirect(String url)
        {
            if (!url.Contains("?"))
                url += "?";
            else
                url += "&";

            url += "rnd=";
            url += DateTime.Now.Ticks.ToString();

            return WriteScript("location.href = '" + url + "';");
        }

        /// <summary>关闭当前页面</summary>
        public virtual IJs Close() { return WriteScript("window.close();"); }
        #endregion
    }

    /// <summary>JavaScript脚本接口</summary>
    public interface IJs
    {
        /// <summary>输出脚本</summary>
        /// <param name="script"></param>
        /// <param name="addScriptTags"></param>
        /// <returns></returns>
        IJs WriteScript(String script, Boolean addScriptTags);

        /// <summary>弹出页面提示</summary>
        /// <param name="message">消息内容</param>
        /// <param name="title">标题</param>
        /// <param name="msDelay">延迟指定毫秒数以后自动关闭，默认0表示不关闭</param>
        /// <param name="kind">种类，info/success/error等</param>
        /// <returns></returns>
        IJs Alert(String message, String title = null, Int32 msDelay = 0, String kind = null);

        /// <summary>停止输出</summary>
        IJs End();

        /// <summary>后退一步</summary>
        IJs Back();

        /// <summary>刷新该页面</summary>
        IJs Refresh();

        /// <summary>重定向到另外的页面</summary>
        /// <param name="url"></param>
        IJs Redirect(String url);

        /// <summary>关闭当前页面</summary>
        IJs Close();
    }
}