using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Web;

namespace GSYWApi.Helper
{
    /// <summary>
    /// 数据表操作类
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class OperationDataHelper<T>
    {
        #region 获取通用表数据查询条件
        /// <summary>
        /// 获取通用表数据查询条件
        /// </summary>
        /// <param name="t">实体类</param>
        /// <param name="QueryType">查询方式：0【模糊查询】，1【精确查询】</param>
        /// <param name="OtherName">查询表定义名称，如A.</param>
        /// <param name="ExcludeName">排除查询的字段</param>
        /// <returns></returns>
        public static string GetWhereSQL(T t, int? QueryType, string OtherName = "", params string[] ExcludeName)
        {
            string WhereSQL = "";

            var pros = typeof(T).GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
            foreach (var item in pros)
            {
                object value = item.GetValue(t, null);
                //如果排除字段中包含当前参数，则执行下一个参数查询
                if (ExcludeName != null && ExcludeName.Contains(item.Name))
                {
                    continue;
                }
                //查询字符串类型参数
                if (IsType(item.PropertyType, "System.String") || item.PropertyType == typeof(String))
                {
                    if (value != null && !string.IsNullOrEmpty(value.ToString()))
                    {
                        WhereSQL += (string.IsNullOrEmpty(WhereSQL) ? "" : " AND ") + OtherName + item.Name +
                            (QueryType == 1 ? " = '" + value + "'" : " like '%" + value + "%'");
                    }
                    continue;
                }
                //查询数字类型或bool型参数
                if (IsType(item.PropertyType, "System.Nullable`1[System.Int16]") ||
                    IsType(item.PropertyType, "System.Nullable`1[System.Int32]") ||
                    IsType(item.PropertyType, "System.Nullable`1[System.Int64]") ||
                    IsType(item.PropertyType, "System.Nullable`1[System.Double]") ||
                    IsType(item.PropertyType, "System.Nullable`1[System.Decimal]") ||
                    IsType(item.PropertyType, "System.Nullable`1[System.Boolean]") ||
                    item.PropertyType == typeof(Int16) || item.PropertyType == typeof(Int32) || item.PropertyType == typeof(Int64) ||
                    item.PropertyType == typeof(Double) || item.PropertyType == typeof(Decimal) || item.PropertyType == typeof(Boolean))
                {
                    if (value != null)
                    {
                        WhereSQL += (string.IsNullOrEmpty(WhereSQL) ? "" : " AND ") + OtherName + item.Name + " = " + value;
                    }
                    continue;
                }
                //查询日期类型参数
                if (IsType(item.PropertyType, "System.Nullable`1[System.DateTime]") ||
                    item.PropertyType == typeof(DateTime))
                {
                    if (value != null)
                    {
                        WhereSQL += (string.IsNullOrEmpty(WhereSQL) ? "" : " AND ") + OtherName + item.Name + " = " +
                            string.Format("TO_DATE('{0}','YYYY/MM/DD HH24:MI:SS')", value);
                    }
                    continue;
                }
            }

            return WhereSQL;
        }
        #endregion

        #region 方法 -> 类型匹配
        /// <summary>
        /// 类型匹配
        /// </summary>
        /// <param name="type">类型</param>
        /// <param name="typeName">类型名称</param>
        /// <returns></returns>
        public static bool IsType(Type type, string typeName)
        {
            if (type.ToString() == typeName)
                return true;
            if (type.ToString() == "System.Object")
                return false;
            return IsType(type.BaseType, typeName);
        }
        #endregion
    }
}