using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WIDESEA_Core.BaseRepository;
using WIDESEA_Core.BaseServices;
using WIDESEA_IBasicService;
using WIDESEA_Model.Models;
using WIDESEA_Model.Models.Basic;

namespace WIDESEA_BasicService
{
    public class MaterialUnitService : ServiceBase<Dt_MaterialUnit, IRepository<Dt_MaterialUnit>>, IMaterialUnitService
    {
        private readonly ILogger<MaterialUnitService> _logger;
        public IRepository<Dt_MaterialUnit> Repository => BaseDal;

        public IRepository<Dt_MaterielInfo> _materielInfoRepository;
        public MaterialUnitService(IRepository<Dt_MaterialUnit> BaseDal, ILogger<MaterialUnitService> logger, IRepository<Dt_MaterielInfo> materielInfoRepository) : base(BaseDal)
        {
            _logger = logger;
            _materielInfoRepository = materielInfoRepository;
        }
        /// <summary>
        /// 单位转换
        /// </summary>
        public async Task<decimal> ConvertAsync(string materialCode, decimal quantity, string fromUnit, string toUnit)
        {
            if (string.IsNullOrEmpty(materialCode))
                throw new ArgumentException("物料编号不能为空");

            if (string.IsNullOrEmpty(fromUnit) || string.IsNullOrEmpty(toUnit))
                throw new ArgumentException("单位不能为空");

            // 如果单位相同，直接返回
            if (fromUnit.Equals(toUnit, StringComparison.OrdinalIgnoreCase))
                return quantity;

            var ratio = await GetConversionRatioAsync(materialCode, fromUnit, toUnit);

            if (ratio == null)
            {
                _logger.LogWarning($"未找到物料 {materialCode} 从 {fromUnit} 到 {toUnit} 的单位转换关系");
                throw new InvalidOperationException($"未找到物料 {materialCode} 从 {fromUnit} 到 {toUnit} 的单位转换关系");
            }

            return quantity * ratio.Value;
        }

        /// <summary>
        /// 采购单位转库存单位
        /// </summary>
        public async Task<decimal> ConvertPurchaseToStockAsync(string materialCode, decimal quantity)
        {
            // 获取物料信息
            var material = await _materielInfoRepository.Db.Queryable<Dt_MaterielInfo>()
                .Where(x => x.MaterielCode == materialCode)
                .FirstAsync();

            if (material == null)
            {
                throw new ArgumentException($"未找到物料编号: {materialCode}");
            }

            return await ConvertAsync(materialCode, quantity, material.purchaseUOM, material.inventoryUOM);
        }

        /// <summary>
        /// 领料单位转库存单位
        /// </summary>
        public async Task<decimal> ConvertIssueToStockAsync(string materialCode, decimal quantity)
        {
            // 获取物料信息
            var material = await _materielInfoRepository.Db.Queryable<Dt_MaterielInfo>()
                .Where(x => x.MaterielCode == materialCode)
                .FirstAsync();

            if (material == null)
            {
                throw new ArgumentException($"未找到物料编号: {materialCode}");
            }

            return await ConvertAsync(materialCode, quantity, material.usageUOM, material.inventoryUOM);
        }
        /// <summary>
        /// 获取单位转换比率
        /// </summary>
        public async Task<decimal?> GetConversionRatioAsync(string materialCode, string fromUnit, string toUnit)
        {
            // 尝试直接查找转换关系
            var conversion = await Repository.Db.Queryable<Dt_MaterialUnit>()
                .Where(x => x.ItemNo == materialCode &&
                           x.FromUom == fromUnit &&
                           x.ToUom == toUnit)
                .FirstAsync();

            if (conversion != null)
            {
                return conversion.Ratio;
            }

            // 尝试查找反向转换关系（取倒数）
            var reverseConversion = await Repository.Db.Queryable<Dt_MaterialUnit>()
                .Where(x => x.ItemNo == materialCode &&
                           x.FromUom == toUnit &&
                           x.ToUom == fromUnit)
                .FirstAsync();

            if (reverseConversion != null)
            {
                return 1 / reverseConversion.Ratio;
            }

            // 尝试通过中间单位（库存单位）进行转换
            var material = await _materielInfoRepository.Db.Queryable<Dt_MaterielInfo>()
                .Where(x => x.MaterielCode == materialCode)
                .FirstAsync();

            if (material != null)
            {
                var stockUnit = material.inventoryUOM;

                // 如果目标单位已经是库存单位，直接查找源单位到库存单位的转换
                if (toUnit.Equals(stockUnit, StringComparison.OrdinalIgnoreCase))
                {
                    var toStockRatio = await GetDirectRatioAsync(materialCode, fromUnit, stockUnit);
                    if (toStockRatio != null) return toStockRatio;
                }

                // 如果源单位是库存单位，直接查找库存单位到目标单位的转换
                if (fromUnit.Equals(stockUnit, StringComparison.OrdinalIgnoreCase))
                {
                    var fromStockRatio = await GetDirectRatioAsync(materialCode, stockUnit, toUnit);
                    if (fromStockRatio != null) return fromStockRatio;
                }

                // 通过库存单位进行间接转换：fromUnit -> stockUnit -> toUnit
                var ratio1 = await GetDirectRatioAsync(materialCode, fromUnit, stockUnit);
                var ratio2 = await GetDirectRatioAsync(materialCode, stockUnit, toUnit);

                if (ratio1 != null && ratio2 != null)
                {
                    return ratio1 * ratio2;
                }
            }

            return null;
        }

        /// <summary>
        /// 获取直接转换比率（包含正向和反向查找）
        /// </summary>
        private async Task<decimal?> GetDirectRatioAsync(string materialCode, string fromUnit, string toUnit)
        {
            // 正向查找
            var conversion = await Repository.Db.Queryable<Dt_MaterialUnit>()
                .Where(x => x.ItemNo == materialCode &&
                           x.FromUom == fromUnit &&
                           x.ToUom == toUnit)
                .FirstAsync();

            if (conversion != null)
            {
                return conversion.Ratio;
            }

            // 反向查找
            var reverseConversion = await Repository.Db.Queryable<Dt_MaterialUnit>()
                .Where(x => x.ItemNo == materialCode &&
                           x.FromUom == toUnit &&
                           x.ToUom == fromUnit)
                .FirstAsync();

            if (reverseConversion != null)
            {
                return 1 / reverseConversion.Ratio;
            }

            return null;
        }

    }
}