AcaMate_API/Program/V1/Services/RepositoryService.cs

using AcaMate.Common.Data;
using AcaMate.Common.Token;
using AcaMate.Common.Models;


using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Linq.Expressions;
using System.Security.Claims;
using Microsoft.IdentityModel.Tokens;

namespace AcaMate.V1.Services;

public interface IRepositoryService
{
    Task<bool> SaveData<T, K>(T entity, Expression<Func<T, K>> key) where T : class;
    Task<ValidateToken> ValidateToken(string token, string refresh);
}

public class RepositoryService: IRepositoryService
{
    private readonly AppDbContext _dbContext;
    private readonly ILogger<RepositoryService> _logger;
    private readonly JwtTokenService _jwtTokenService;

    public RepositoryService(AppDbContext dbContext, ILogger<RepositoryService> logger, JwtTokenService jwtTokenService)
    {
        _dbContext = dbContext;
        _logger = logger;
        _jwtTokenService = jwtTokenService;
    }
    
    public async Task<bool> SaveData<T, K> (T entity, Expression<Func<T, K>> key) where T : class
    {
        try
        {
            var value = key.Compile()(entity);

            // x 라 함은 Expression 으로 생성되는 트리에서 T 타입으의 매개변수를 지칭함
            var parameter = Expression.Parameter(typeof(T), "x");
            
            var invokedExpr = Expression.Invoke(key, parameter);
            var constantExpr = Expression.Constant(value, key.Body.Type);
            var equalsExpr = Expression.Equal(invokedExpr, constantExpr);
            
            var predicate = Expression.Lambda<Func<T, bool>>(equalsExpr, parameter);
            
            var dbSet = _dbContext.Set<T>();
            
            var entityData = await dbSet.FirstOrDefaultAsync(predicate);
            
            if (entityData != null)
            {
                _logger.LogInformation($"[{typeof(T)}] 해당 PK 존재 [{value}]: 계속");
                var entry = _dbContext.Entry(entityData);
                entry.CurrentValues.SetValues(entity);
                if (entry.Properties.Any(p => p.IsModified))
                {
                    _logger.LogInformation($"[{typeof(T)}] 변경사항 존재: 계속");
                }
                else
                {
                    _logger.LogInformation($"[{typeof(T)}] 변경사항 없음: 종료");
                    return true;
                }
            }
            else
            {
                _logger.LogInformation($"[{typeof(T)}] 처음등록");
                dbSet.Add(entity);
            }
            
            await _dbContext.SaveChangesAsync();
            _logger.LogInformation($"[{typeof(T)}] DB 저장 완료: 종료");
            return true;
        }
        catch (Exception ex)
        {
            _logger.LogInformation($"[{typeof(T)}] 알 수 없는 오류: 종료 {ex}");
            return false;
        }
    }
    
    //토큰 태울때는 인코딩 된 걸로 태워야지 원본꺼 태우면 데이터에 손상옵니다.
    public async Task<ValidateToken> ValidateToken(string token, string refresh)
    {
        var principalToken = _jwtTokenService.ValidateToken(token);
        if (principalToken != null)
        {
            var uid = principalToken.FindFirst(ClaimTypes.NameIdentifier)?.Value ?? string.Empty;
            _logger.LogInformation($"토큰 변환 - {uid}");
            return new ValidateToken
            {
                token = token,
                refresh = refresh,
                uid = uid
            };
        }
        else
        {
            _logger.LogInformation("엑세스 토큰 만료");
            var refreshToken = await _dbContext.RefreshTokens
                .FirstOrDefaultAsync(t => t.refresh_token == refresh);
            if (refreshToken == null)
            {
                throw new SecurityTokenException("리프레시 토큰도 잘못되었음");
            }
            var uid = refreshToken.uid;

            if (refreshToken.expire_date > DateTime.Now)
            {
                _logger.LogInformation($"리프레시 : {uid}");
                var access = _jwtTokenService.GenerateJwtToken(uid);
                return new ValidateToken
                {
                    token = access,
                    refresh = refreshToken.refresh_token,
                    uid = uid
                };
            }
            else
            {
                refreshToken = _jwtTokenService.GenerateRefreshToken(uid);
                _logger.LogInformation("리프레시 토큰 만료");
                await SaveData<RefreshToken, string>(refreshToken, rt => rt.uid);
                return new ValidateToken
                {
                    token = token,
                    refresh = refreshToken.refresh_token,
                    uid = uid
                };
            }
        }
    }
    
}