FACULTATE-HEALTHCARE_MANAGER/backend/Application/Endpoints/Authorization/UserLogin/UserLoginHandler.cs

using Application.Services.Database.PostgreSQL;
using Application.Services.HashingAlgorithms;
using Application.Services.Jwt;
using Domain;

namespace Application.Endpoints.Authorization.UserLogin;

public class UserLoginHandler(
    IJwtService jwtService,
    IHashingAlgorithms hashingAlgorithms,
    IDoctorRepository doctorRepository,
    IPatientRepository patientRepository,
    IAdminRepository adminRepository)
{
    public async Task<BaseResponse> Handle(UserLoginCommand request, CancellationToken token)
    {
        var validator = new UserLoginValidator();
        var result = await validator.ValidateAsync(request, token);
        if (!result.IsValid)
        {
            var firstError = result.Errors.FirstOrDefault();
            var errorCode = int.TryParse(firstError.ErrorCode, out var code) ? code : -1;
            var errorMessage = firstError.ErrorMessage;

            return new BaseResponse
            {
                StatusCode = errorCode,
                Message = errorMessage,
                Data = null
            };
        }

        var email = request.Email;
        var password = hashingAlgorithms.Sha256Algorithm(request.Password);

        if (await doctorRepository.CredentialsMatch(email, password, token))
        {
            var doctor = await doctorRepository.FindByEmailAsync(email, token);
            var authToken = jwtService.GenerateJwtToken(doctor.Id, UserRoles.Doctor, doctor.Name);
            return new BaseResponse
            {
                StatusCode = HttpStatusCodes.OK,
                Message = "Doctor logged in successfully.",
                Data = authToken
            };
        }

        if (await patientRepository.CredentialsMatch(email, password, token))
        {
            var patient = await patientRepository.FindByEmailAsync(email, token);
            var authToken = jwtService.GenerateJwtToken(patient.Id, UserRoles.Patient, patient.Name);
            return new BaseResponse
            {
                StatusCode = HttpStatusCodes.OK,
                Message = "Patient logged in successfully.",
                Data = authToken
            };
        }

        if (await adminRepository.CredentialsMatch(email, password, token))
        {
            var admin = await adminRepository.FindByEmailAsync(email, token);
            var authToken = jwtService.GenerateJwtToken(admin.Id, UserRoles.Admin, admin.Name);
            return new BaseResponse
            {
                StatusCode = HttpStatusCodes.OK,
                Message = "Admin logged in successfully.",
                Data = authToken
            };
        }

        return new BaseResponse
        {
            StatusCode = HttpStatusCodes.NotFound,
            Message = "User not registered in our system.",
            Data = null
        };
    }
}