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

namespace HoneyBox.Core.Services;

/// <summary>
/// 用户服务实现
/// </summary>
public class UserService : BaseService<User, int>, IUserService
{
    private readonly ILogger<UserService> _logger;

    public UserService(HoneyBoxDbContext dbContext, ILogger<UserService> logger)
        : base(dbContext)
    {
        _logger = logger;
    }

    /// <inheritdoc/>
    public async Task<User?> GetUserByIdAsync(int userId)
    {
        return await _dbSet.FirstOrDefaultAsync(u => u.Id == userId);
    }

    /// <inheritdoc/>
    public async Task<User?> GetUserByOpenIdAsync(string openId)
    {
        if (string.IsNullOrWhiteSpace(openId))
            return null;

        return await _dbSet.FirstOrDefaultAsync(u => u.OpenId == openId);
    }

    /// <inheritdoc/>
    public async Task<User?> GetUserByUnionIdAsync(string unionId)
    {
        if (string.IsNullOrWhiteSpace(unionId))
            return null;

        return await _dbSet.FirstOrDefaultAsync(u => u.UnionId == unionId);
    }

    /// <inheritdoc/>
    public async Task<User?> GetUserByMobileAsync(string mobile)
    {
        if (string.IsNullOrWhiteSpace(mobile))
            return null;

        return await _dbSet.FirstOrDefaultAsync(u => u.Mobile == mobile);
    }

    /// <inheritdoc/>
    public async Task<User> CreateUserAsync(CreateUserDto dto)
    {
        if (dto == null)
            throw new ArgumentNullException(nameof(dto));

        // Generate UID
        var uid = GenerateUid();

        var user = new User
        {
            OpenId = dto.OpenId ?? string.Empty,
            UnionId = dto.UnionId,
            Mobile = dto.Mobile,
            Uid = uid,
            Nickname = dto.Nickname ?? $"User{Random.Shared.Next(1000, 9999)}",
            HeadImg = dto.Headimg ?? string.Empty,
            Pid = dto.Pid,
            ClickId = dto.ClickId,
            Money = 0,
            Money2 = 0,
            Integral = 0,
            Score = 0,
            Vip = 0,
            Status = 1,
            IsTest = 0,
            CreatedAt = DateTime.UtcNow,
            UpdatedAt = DateTime.UtcNow
        };

        await _dbSet.AddAsync(user);
        await _dbContext.SaveChangesAsync();

        _logger.LogInformation($"User created: Id={user.Id}, Uid={user.Uid}, OpenId={user.OpenId}");

        return user;
    }

    /// <inheritdoc/>
    public async Task UpdateUserAsync(int userId, UpdateUserDto dto)
    {
        if (dto == null)
            throw new ArgumentNullException(nameof(dto));

        var user = await GetUserByIdAsync(userId);
        if (user == null)
            throw new InvalidOperationException($"User with id {userId} not found");

        if (!string.IsNullOrWhiteSpace(dto.Nickname))
            user.Nickname = dto.Nickname;

        if (!string.IsNullOrWhiteSpace(dto.Headimg))
            user.HeadImg = dto.Headimg;

        if (!string.IsNullOrWhiteSpace(dto.Mobile))
            user.Mobile = dto.Mobile;

        if (!string.IsNullOrWhiteSpace(dto.UnionId))
            user.UnionId = dto.UnionId;

        user.UpdatedAt = DateTime.UtcNow;

        _dbSet.Update(user);
        await _dbContext.SaveChangesAsync();

        _logger.LogInformation($"User updated: Id={user.Id}");
    }

    /// <inheritdoc/>
    public async Task<UserInfoDto?> GetUserInfoAsync(int userId)
    {
        var user = await GetUserByIdAsync(userId);
        if (user == null)
            return null;

        var couponCount = await _dbContext.CouponReceives
            .Where(cr => cr.UserId == userId && cr.State == 0)
            .CountAsync();

        var registrationDays = (int)(DateTime.UtcNow - user.CreatedAt).TotalDays;

        var maskedMobile = MaskMobileNumber(user.Mobile);
        var mobileIs = string.IsNullOrWhiteSpace(user.Mobile) ? 0 : 1;

        // 计算权益等级信息
        var quanYiLevel = await CalculateQuanYiLevelAsync(user.Score);

        return new UserInfoDto
        {
            Id = user.Id,
            Uid = user.Uid,
            Nickname = user.Nickname,
            Headimg = user.HeadImg,
            Mobile = maskedMobile,
            MobileIs = mobileIs,
            Money = user.Money,
            Money2 = user.Money2 ?? 0,
            Integral = user.Integral,
            Score = user.Score,
            Vip = user.Vip,
            VipImgurl = GetVipImageUrl(user.Vip),
            Coupon = couponCount,
            Day = registrationDays,
            QuanYiLevel = quanYiLevel
        };
    }

    /// <summary>
    /// 计算用户权益等级信息
    /// </summary>
    /// <param name="score">用户欧气值</param>
    /// <returns>权益等级DTO</returns>
    private async Task<QuanYiLevelDto> CalculateQuanYiLevelAsync(decimal score)
    {
        var userScore = (int)score;

        // 获取所有权益等级，按所需积分升序排列
        var levels = await _dbContext.EquityLevels
            .Where(e => e.DeletedAt == null)
            .OrderBy(e => e.RequiredPoints)
            .ToListAsync();

        if (!levels.Any())
        {
            return new QuanYiLevelDto { Level = 0, Cha = -1, Jindu = 0 };
        }

        // 找到当前等级和下一等级
        int currentLevel = 0;
        int currentLevelPoints = 0;
        int nextLevelPoints = 0;
        bool isMaxLevel = false;

        for (int i = 0; i < levels.Count; i++)
        {
            if (userScore >= levels[i].RequiredPoints)
            {
                currentLevel = levels[i].Level;
                currentLevelPoints = levels[i].RequiredPoints;

                if (i + 1 < levels.Count)
                {
                    nextLevelPoints = levels[i + 1].RequiredPoints;
                }
                else
                {
                    isMaxLevel = true;
                }
            }
            else
            {
                if (currentLevel == 0)
                {
                    // 用户还没达到第一级
                    nextLevelPoints = levels[i].RequiredPoints;
                }
                break;
            }
        }

        // 计算差值和进度
        int cha = isMaxLevel ? -1 : nextLevelPoints - userScore;
        int jindu = 0;

        if (isMaxLevel)
        {
            jindu = 100;
        }
        else if (nextLevelPoints > currentLevelPoints)
        {
            var progress = (userScore - currentLevelPoints) * 100 / (nextLevelPoints - currentLevelPoints);
            jindu = Math.Max(0, Math.Min(100, progress));
        }

        return new QuanYiLevelDto
        {
            Level = currentLevel,
            Cha = cha,
            Jindu = jindu
        };
    }

    /// <inheritdoc/>
    public async Task<int> CalculateVipLevelAsync(int userId, int currentVip)
    {
        var user = await GetUserByIdAsync(userId);
        if (user == null)
            return currentVip;

        // Get all VIP levels ordered by level
        var vipLevels = await _dbContext.VipLevels
            .Where(v => v.DeletedAt == null)
            .OrderBy(v => v.Level)
            .ToListAsync();

        if (!vipLevels.Any())
            return currentVip;

        // Calculate VIP level based on total spending (Money)
        var totalSpending = user.Money;

        int newVipLevel = 0;
        foreach (var vipLevel in vipLevels)
        {
            if (totalSpending >= vipLevel.Number)
            {
                newVipLevel = vipLevel.Level;
            }
            else
            {
                break;
            }
        }

        return newVipLevel;
    }

    /// <summary>
    /// Generate a unique UID for new user
    /// </summary>
    private string GenerateUid()
    {
        // Generate a numeric UID based on timestamp and random number
        var timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
        var random = Random.Shared.Next(1000, 9999);
        return $"{timestamp}{random}";
    }

    /// <summary>
    /// Mask mobile number for privacy (e.g., 13812345678 -> 138****5678)
    /// </summary>
    private string? MaskMobileNumber(string? mobile)
    {
        if (string.IsNullOrWhiteSpace(mobile) || mobile.Length < 11)
            return null;

        return $"{mobile.Substring(0, 3)}****{mobile.Substring(mobile.Length - 4)}";
    }

    /// <summary>
    /// Get VIP image URL based on VIP level
    /// </summary>
    private string? GetVipImageUrl(int vipLevel)
    {
        if (vipLevel <= 0)
            return null;

        // Return a placeholder URL - actual URLs should be configured
        return $"https://example.com/vip/level_{vipLevel}.png";
    }
}