using ToolHub.Models;
using System.Security.Cryptography;
using System.Text;

namespace ToolHub.Services;

public class UserService : IUserService
{
    private readonly IFreeSql _freeSql;

    public UserService(IFreeSql freeSql)
    {
        _freeSql = freeSql;
    }

    public async Task<User?> GetUserByIdAsync(int id)
    {
        return await _freeSql.Select<User>()
            .Where(u => u.Id == id && u.IsActive)
            .FirstAsync();
    }

    public async Task<User?> GetUserByEmailAsync(string email)
    {
        return await _freeSql.Select<User>()
            .Where(u => u.Email == email && u.IsActive)
            .FirstAsync();
    }

    public async Task<bool> CreateUserAsync(User user)
    {
        try
        {
            user.PasswordHash = HashPassword(user.PasswordHash);
            await _freeSql.Insert(user).ExecuteAffrowsAsync();
            return true;
        }
        catch
        {
            return false;
        }
    }

    public async Task<bool> UpdateUserAsync(User user)
    {
        try
        {
            user.UpdatedAt = DateTime.Now;
            await _freeSql.Update<User>()
                .SetSource(user)
                .ExecuteAffrowsAsync();
            return true;
        }
        catch
        {
            return false;
        }
    }

    public async Task<bool> VerifyPasswordAsync(string email, string password)
    {
        var user = await GetUserByEmailAsync(email);
        if (user == null) return false;

        return VerifyPassword(password, user.PasswordHash);
    }

    public async Task<List<Tool>> GetUserFavoritesAsync(int userId)
    {
        var favorites = await _freeSql.Select<UserFavorite>()
            .Include(uf => uf.Tool.Category)
            .Where(uf => uf.UserId == userId)
            .OrderByDescending(uf => uf.CreatedAt)
            .ToListAsync();

        return favorites.Select(uf => uf.Tool).ToList();
    }

    public async Task<bool> AddFavoriteAsync(int userId, int toolId)
    {
        try
        {
            var existing = await _freeSql.Select<UserFavorite>()
                .Where(uf => uf.UserId == userId && uf.ToolId == toolId)
                .FirstAsync();

            if (existing != null) return true;

            await _freeSql.Insert(new UserFavorite
            {
                UserId = userId,
                ToolId = toolId
            }).ExecuteAffrowsAsync();

            // 更新工具收藏数
            await _freeSql.Update<Tool>()
                .Where(t => t.Id == toolId)
                .Set(t => t.FavoriteCount + 1)
                .ExecuteAffrowsAsync();

            return true;
        }
        catch
        {
            return false;
        }
    }

    public async Task<bool> RemoveFavoriteAsync(int userId, int toolId)
    {
        try
        {
            await _freeSql.Delete<UserFavorite>()
                .Where(uf => uf.UserId == userId && uf.ToolId == toolId)
                .ExecuteAffrowsAsync();

            // 更新工具收藏数
            await _freeSql.Update<Tool>()
                .Where(t => t.Id == toolId)
                .Set(t => t.FavoriteCount - 1)
                .ExecuteAffrowsAsync();

            return true;
        }
        catch
        {
            return false;
        }
    }

    public async Task<bool> IsFavoriteAsync(int userId, int toolId)
    {
        var favorite = await _freeSql.Select<UserFavorite>()
            .Where(uf => uf.UserId == userId && uf.ToolId == toolId)
            .FirstAsync();

        return favorite != null;
    }

    private string HashPassword(string password)
    {
        using var sha256 = SHA256.Create();
        var hashedBytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(password + "ToolHub_Salt"));
        return Convert.ToBase64String(hashedBytes);
    }

    private bool VerifyPassword(string password, string hash)
    {
        var computedHash = HashPassword(password);
        return computedHash == hash;
    }
}