using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;

using HH.WCS.Mobox3.DSZSH.models;

using SqlSugar;

namespace HH.WCS.Mobox3.DSZSH.wms {
    /// <summary>
    /// 数据库 [ 查询表达式 ] 构造类
    /// </summary>
    public class DbExpr {
        /// <summary>
        /// 通用 [ 货位 ] 筛选
        /// </summary>
        /// <remarks><code><![CDATA[
        /// l => l.C_ENABLE == "Y" 
        ///   && l.N_LOCK_STATE == @lock && l.S_LOCK_STATE == TN_Location.GetLockStateStr(@lock)
        ///   && l.S_CODE == name
        ///   && areas.Contains(l.S_AREA_CODE)
        ///   && l.N_CURRENT_NUM == curNum
        /// ]]></code></remarks>
        /// <param name="lock">锁状态 ( 小于 0 时忽略 )</param>
        /// <param name="name">货位名称 ( 为 null 或 "" 时忽略 )</param>
        /// <param name="areas">所在库区列表 ( 为 null 或 [] 时忽略 )</param>
        /// <param name="curNum">当前数量 ( 小于 0 时忽略 )</param>
        /// <returns></returns>
        public static Expression<Func<TN_Location, bool>> LocFilter(int @lock = 0, string name = "", 
            List<string> areas = null, int curNum = -1) {

            Expression<Func<TN_Location, bool>> expr = l => l.C_ENABLE == "Y"; // 已启用

            if (@lock >= 0) {
                Expression<Func<TN_Location, bool>> newExpr = 
                    l => l.N_LOCK_STATE == @lock && l.S_LOCK_STATE == TN_Location.GetLockStateStr(@lock);
                expr = Expression.Lambda<Func<TN_Location, bool>>(Expression.AndAlso(expr.Body, newExpr.Body), expr.Parameters[0]);
            }
            if (!string.IsNullOrEmpty(name)) {
                Expression<Func<TN_Location, bool>> newExpr = l => l.S_CODE == name;
                expr = Expression.Lambda<Func<TN_Location, bool>>(Expression.AndAlso(expr.Body, newExpr.Body), expr.Parameters[0]);
            }
            if (areas != null && areas.Count > 0) {
                Expression<Func<TN_Location, bool>> newExpr = l => areas.Contains(l.S_AREA_CODE);
                expr = Expression.Lambda<Func<TN_Location, bool>>(Expression.AndAlso(expr.Body, newExpr.Body), expr.Parameters[0]);
            }
            if (curNum >= 0) {
                Expression<Func<TN_Location, bool>> newExpr = l => l.N_CURRENT_NUM == curNum;
                expr = Expression.Lambda<Func<TN_Location, bool>>(Expression.AndAlso(expr.Body, newExpr.Body), expr.Parameters[0]);
            }
            
            return expr;
        }

        /// <summary>
        /// 起点货位 ( 未绑定 )
        /// </summary>
        /// <remarks><code><![CDATA[
        /// l => l.C_ENABLE == "Y" 
        ///   && l.N_LOCK_STATE == 0 && l.S_LOCK_STATE == "无"
        ///   && l.S_CODE == name
        ///   && areas.Contains(l.S_AREA_CODE)
        ///   && l.N_CURRENT_NUM == 0
        /// ]]></code></remarks>
        /// <param name="name">货位名称 ( 为 null 或 "" 时忽略 )</param>
        /// <param name="areas">所在库区列表 ( 为 null 或 [] 时忽略 )</param>
        /// <returns></returns>
        public static Expression<Func<TN_Location, bool>> StartLocUnbind(string name = "", List<string> areas = null) {
            return LocFilter(0, name, areas, 0);
        }

        /// <summary>
        /// 起点货位 ( 已绑定 )
        /// </summary>
        /// <remarks><code><![CDATA[
        /// l => l.C_ENABLE == "Y" 
        ///   && l.N_LOCK_STATE == 0 && l.S_LOCK_STATE == "无"
        ///   && l.S_CODE == name
        ///   && areas.Contains(l.S_AREA_CODE)
        ///   && l.N_CURRENT_NUM == 1
        /// ]]></code></remarks>
        /// <param name="name">货位名称 ( 为 null 或 "" 时忽略 )</param>
        /// <param name="areas">所在库区列表 ( 为 null 或 [] 时忽略 )</param>
        /// <param name="curNum">当前数量 ( 小于 0 时忽略 )</param>
        /// <returns></returns>
        public static Expression<Func<TN_Location, bool>> StartLoc(string name = "", List<string> areas = null, int curNum = 1) {
            return LocFilter(0, name, areas, curNum);
        }

        /// <summary>
        /// 终点货位
        /// </summary>
        /// <remarks><code><![CDATA[
        /// l => l.C_ENABLE == "Y" 
        ///   && l.N_LOCK_STATE == 0 && l.S_LOCK_STATE == "无"
        ///   && l.S_CODE == name
        ///   && areas.Contains(l.S_AREA_CODE)
        ///   && l.N_CURRENT_NUM == 0
        /// ]]></code></remarks>
        /// <param name="name">货位名称 ( 为 null 或 "" 时忽略 )</param>
        /// <param name="areas">所在库区列表 ( 为 null 或 [] 时忽略 )</param>
        /// <param name="curNum">当前数量 ( 小于 0 时忽略 )</param>
        /// <returns></returns>
        public static Expression<Func<TN_Location, bool>> EndLoc(string name = "", List<string> areas = null, int curNum = 0) {
            return LocFilter(0, name, areas, curNum);
        }
    }
}