using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Script.Serialization;
using System.Xml.Serialization;
using NewLife.Collections;
using NewLife.Web;

namespace NewLife.Cube
{
    /// <summary>页面助手</summary>
    public static class PagerHelper
    {
        #region 名称
        /// <summary>名称类。用户可根据需要修改Url参数名</summary>
        public class __
        {
            /// <summary>排序字段</summary>
            public String Sort = "Sort";

            /// <summary>是否降序</summary>
            public String Desc = "Desc";

            /// <summary>页面索引</summary>
            public String PageIndex = "PageIndex";

            /// <summary>页面大小</summary>
            public String PageSize = "PageSize";
        }

        /// <summary>名称类。用户可根据需要修改Url参数名</summary>
        [XmlIgnore, ScriptIgnore]
        public static __ _ = new __();
        #endregion

        /// <summary>获取表单提交的Url</summary>
        /// <param name="pager">页面</param>
        /// <param name="action">动作</param>
        /// <returns></returns>
        public static String GetFormAction(this Pager pager, String action = null)
        {
            var req = HttpContext.Current?.Request;
            if (req == null) return action;

            // 表单提交，不需要排序、分页，不需要表单提交上来的数据，只要请求字符串过来的数据
            var query = req.QueryString;
            var forms = new HashSet<String>(req.Form.AllKeys, StringComparer.OrdinalIgnoreCase);
            var excludes = new HashSet<String>(new[] { _.Sort, _.Desc, _.PageIndex, _.PageSize }, StringComparer.OrdinalIgnoreCase);

            var url = Pool.StringBuilder.Get();
            foreach (var item in query.AllKeys)
            {
                // 只要查询字符串，不要表单
                if (forms.Contains(item)) continue;

                // 排除掉排序和分页
                if (excludes.Contains(item)) continue;

                // 内容为空也不要
                var v = query[item];
                if (v.IsNullOrEmpty()) continue;

                url.UrlParam(item, v);
            }

            if (url.Length == 0) return action;
            if (!action.Contains('?')) action += '?';

            return action + url.Put(true);
        }
    }
}