using HoneyBox.Core.Interfaces;
using HoneyBox.Model.Data;
using HoneyBox.Model.Entities;
using HoneyBox.Model.Models.Vip;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;

namespace HoneyBox.Core.Services;

/// <summary>
/// VIP服务实现
/// </summary>
public class VipService : IVipService
{
    private readonly HoneyBoxDbContext _dbContext;
    private readonly ILogger<VipService> _logger;

    public VipService(HoneyBoxDbContext dbContext, ILogger<VipService> logger)
    {
        _dbContext = dbContext;
        _logger = logger;
    }

    /// <inheritdoc />
    public async Task<VipInfoResponse> GetVipInfoAsync(int userId)
    {
        // 获取用户信息
        var user = await _dbContext.Users
            .Where(u => u.Id == userId)
            .Select(u => new { u.Id, u.Nickname, u.HeadImg, u.Vip })
            .FirstOrDefaultAsync();

        if (user == null)
        {
            throw new InvalidOperationException("用户不存在");
        }

        // 计算并更新VIP等级
        var currentVip = await CalculateVipLevelAsync(userId, user.Vip);

        // 获取所有VIP等级列表
        var vipLevels = await _dbContext.VipLevels
            .Where(v => v.DeletedAt == null)
            .OrderBy(v => v.Level)
            .ToListAsync();

        // 获取最大VIP等级
        var maxVipLevel = vipLevels.Any() ? vipLevels.Max(v => v.Level) : 0;

        // 构建用户VIP信息
        var userInfo = new VipUserInfoDto
        {
            Nickname = user.Nickname,
            Headimg = user.HeadImg,
            Vip = currentVip,
            UpgradeMoney = "0",
            LastVip = 0,
            JinDu = 0,
            Notice = string.Empty
        };

        // 如果未达到最高等级，计算升级进度
        if (currentVip < maxVipLevel)
        {
            // 计算累计消费
            var totalOrder = await GetTotalOrderConsumptionAsync(userId);

            // 获取下一个VIP等级的条件
            var nextLevel = vipLevels
                .Where(v => v.Level > currentVip)
                .OrderBy(v => v.Level)
                .FirstOrDefault();

            if (nextLevel != null)
            {
                var upgradeMoney = nextLevel.Number - totalOrder;
                userInfo.UpgradeMoney = upgradeMoney > 0 ? upgradeMoney.ToString("F2") : "0";
                userInfo.LastVip = nextLevel.Level;

                // 计算进度百分比
                if (totalOrder >= nextLevel.Number)
                {
                    userInfo.JinDu = 100;
                }
                else if (nextLevel.Number > 0)
                {
                    userInfo.JinDu = Math.Round((decimal)totalOrder / nextLevel.Number * 100, 2);
                }
            }
        }
        else
        {
            userInfo.UpgradeMoney = "0";
            userInfo.LastVip = 0;
            userInfo.JinDu = 100;
        }

        // 获取当前等级的提示信息
        var currentLevelInfo = vipLevels.FirstOrDefault(v => v.Level == currentVip);
        if (currentLevelInfo != null)
        {
            userInfo.Notice = currentLevelInfo.Title; // 使用标题作为提示信息
        }

        // 构建VIP等级列表DTO
        var vipLevelDtos = vipLevels.Select(v => new VipLevelDto
        {
            Id = v.Id,
            Level = v.Level,
            Title = v.Title,
            Imgurl = string.Empty, // SQL Server表中没有imgurl字段
            Condition = v.Number,
            Discount = 0, // SQL Server表中没有discount字段
            Notice = v.Title
        }).ToList();

        return new VipInfoResponse
        {
            Userinfo = userInfo,
            Data = vipLevelDtos
        };
    }

    /// <inheritdoc />
    public async Task<int> CalculateVipLevelAsync(int userId, int currentVip)
    {
        // 计算累计消费
        var totalOrder = await GetTotalOrderConsumptionAsync(userId);

        // 查找符合升级条件的最高等级
        // 条件：等级 > 当前等级 且 升级条件 <= 累计消费
        var newVipLevel = await _dbContext.VipLevels
            .Where(v => v.DeletedAt == null)
            .Where(v => v.Level > currentVip)
            .Where(v => v.Number <= totalOrder)
            .OrderByDescending(v => v.Level)
            .FirstOrDefaultAsync();

        if (newVipLevel != null)
        {
            // 更新用户VIP等级
            var user = await _dbContext.Users.FindAsync(userId);
            if (user != null)
            {
                user.Vip = (byte)newVipLevel.Level;
                await _dbContext.SaveChangesAsync();
                _logger.LogInformation("用户 {UserId} VIP等级从 {OldVip} 升级到 {NewVip}", 
                    userId, currentVip, newVipLevel.Level);
            }
            return newVipLevel.Level;
        }

        return currentVip;
    }

    /// <inheritdoc />
    public async Task<List<VipLevelDto>> GetVipLevelsAsync()
    {
        var vipLevels = await _dbContext.VipLevels
            .Where(v => v.DeletedAt == null)
            .OrderBy(v => v.Level)
            .ToListAsync();

        return vipLevels.Select(v => new VipLevelDto
        {
            Id = v.Id,
            Level = v.Level,
            Title = v.Title,
            Imgurl = string.Empty,
            Condition = v.Number,
            Discount = 0,
            Notice = v.Title
        }).ToList();
    }

    /// <summary>
    /// 获取用户累计订单消费金额
    /// </summary>
    /// <param name="userId">用户ID</param>
    /// <returns>累计消费金额</returns>
    private async Task<decimal> GetTotalOrderConsumptionAsync(int userId)
    {
        // 计算累计消费：status=1（已支付）且 order_type<5
        var totalOrder = await _dbContext.Orders
            .Where(o => o.UserId == userId)
            .Where(o => o.Status == 1)
            .Where(o => o.OrderType < 5)
            .SumAsync(o => o.OrderTotal);

        return totalOrder;
    }
}