using Application.Services.Database;
using Application.Services.Database.MongoDB;
using Core.Entities;

namespace Application.Endpoints.Appointments;

public class AppointmentManagementHandler
{
    private readonly IAppointmentsMongoDbService _appointmentsMongoDbService;
    private readonly IPatientRepository _patientRepository;
    private readonly IDoctorRepository _doctorRepository;

    public AppointmentManagementHandler(IAppointmentsMongoDbService appointmentsMongoDbService,
        IPatientRepository patientRepository, IDoctorRepository doctorRepository)
    {
        _appointmentsMongoDbService = appointmentsMongoDbService;
        _patientRepository = patientRepository;
        _doctorRepository = doctorRepository;
    }

    public async Task<BaseResponse> HandleCreateAppointment(AppointmentManagementDto dto)
    {
        var validation = new CreateAppointmentValidator(_appointmentsMongoDbService,
            _doctorRepository, _patientRepository);
        var validationResult = await validation.ValidateAsync(dto);

        if (!validationResult.IsValid)
        {
            var firstError = validationResult.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 appointmentId = IdentifierGenerator.GenerateId(dto.DoctorId, dto.PatientId);
        var criteria = new List<(string FieldName, string Value)>
        {
            ("_id", appointmentId),
        };
        var appointments = await _appointmentsMongoDbService.FindAsync<Appointment>(criteria);
        
        if(!appointments.Any())
        {
            var appointment = new Appointment();
            appointment.SetId(appointmentId);
            appointment.SetDoctorIid(dto.DoctorId.ToString());
            appointment.SetPatientId(dto.PatientId.ToString());
            appointment.AddAppointment(dto.Appointment);
            
            await _appointmentsMongoDbService.AddAsync(appointment);
        }
        else
        {
            var appointment = appointments[0];
            appointment.AddAppointment(dto.Appointment);
            await _appointmentsMongoDbService.ModifyAsync("_id", appointmentId, appointment);
        }

        return new BaseResponse()
        {
            StatusCode = HttpStatusCodes.Created,
            Message = "Appointment successfully created.",
            Data = null
        };
    }
    
    public async Task<BaseResponse> HandleDeleteAppointment(AppointmentManagementDto dto)
    {
        var validation = new DeleteAppointmentValidator(_appointmentsMongoDbService,
            _doctorRepository, _patientRepository);
        var validationResult = await validation.ValidateAsync(dto);

        if (!validationResult.IsValid)
        {
            var firstError = validationResult.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 appointmentId = IdentifierGenerator.GenerateId(dto.DoctorId, dto.PatientId);
        var criteria = new List<(string FieldName, string Value)>
        {
            ("_id", appointmentId),
        };
        var appointments = await _appointmentsMongoDbService.FindAsync<Appointment>(criteria);
        
        if(!appointments.Any())
        {
            return new BaseResponse()
            {
                StatusCode = HttpStatusCodes.NotFound,
                Message = "Appointment not found in system.",
                Data = null
            };
        }
    
        var appointment = appointments[0];
        appointment.RemoveAppointment(dto.Appointment);
        await _appointmentsMongoDbService.ModifyAsync("_id", appointmentId, appointment);

        return new BaseResponse()
        {
            StatusCode = HttpStatusCodes.OK,
            Message = "Appointment successfully removed.",
            Data = null
        };
    }
}