using System;
using System.Linq.Expressions;
using SqlSugar;

namespace Mtxfw.Utility.DataAccess
{
    public partial class Sql : DbHelperSqlSugar
    {
        public Sql()
        {
        }

        /// <summary>
        /// 条件查询
        /// </summary>
        /// <returns></returns>
        public SqlSugarClient Sugar()
        {
            return Db;
        }

        /// <summary>
        /// 条件查询
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <returns></returns>
        public ISugarQueryable<T> Queryable<T>() where T : class, new()
        {
            return Db.Queryable<T>();
        }

        /// <summary>
        /// 是否存在记录
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public bool Exists<T>(Expression<Func<T, bool>> predicate) where T : class, new()
        {
            return Db.Queryable<T>().Any(predicate);
        }

        /// <summary>
        /// 查询最大值 (单个字段)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public int Max<T>(Expression<Func<T, bool>> predicate, Expression<Func<T, int>> maxField) where T : class, new()
        {
            return Db.Queryable<T>().Where(predicate).Max(maxField);
        }

        /// <summary>
        /// 查询最小值 (单个字段)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public int Min<T>(Expression<Func<T, bool>> predicate, Expression<Func<T, int>> minField) where T : class, new()
        {
            return Db.Queryable<T>().Where(predicate).Min(minField);
        }

        /// <summary>
        /// 查询最小值 (单个字段)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public object Min<T>(Expression<Func<T, bool>> predicate, Expression<Func<T, object>> minField) where T : class, new()
        {
            return Db.Queryable<T>().Where(predicate).Min(minField);
        }

        /// <summary>
        /// 查询总和 (单个字段)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public decimal Sum<T>(Expression<Func<T, bool>> predicate, Expression<Func<T, decimal>> sumField) where T : class, new()
        {
            return Db.Queryable<T>().Where(predicate).Sum(sumField);
        }

        /// <summary>
        /// 查询平均值 (单个字段)
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="predicate"></param>
        /// <returns></returns>
        public decimal Avg<T>(Expression<Func<T, bool>> predicate, Expression<Func<T, decimal>> avgField) where T : class, new()
        {
            return Db.Queryable<T>().Where(predicate).Avg(avgField);
        }
    }
}