package service

import (
	"context"
	"errors"

	"github.com/google/uuid"

	"apskel-pos-be/internal/appcontext"
	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/contract"
	"apskel-pos-be/internal/models"
	"apskel-pos-be/internal/processor"
	"apskel-pos-be/internal/repository"
)

// CustomerPinService serves the customer's PIN (docs/prd-point-coin.md F11) and the
// dashboard's view of it.
type CustomerPinService interface {
	Status(ctx context.Context, customerID uuid.UUID) *contract.Response
	RequestOtp(ctx context.Context, customerID uuid.UUID, req *contract.RequestPinOtpRequest) *contract.Response
	CreatePin(ctx context.Context, customerID uuid.UUID, req *contract.CreateCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response
	ChangePin(ctx context.Context, customerID uuid.UUID, req *contract.ChangeCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response
	ResetPin(ctx context.Context, customerID uuid.UUID, req *contract.ResetCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response

	RemovePin(ctx context.Context, apctx *appcontext.ContextInfo, customerID uuid.UUID, req *contract.RemoveCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response
	ListSecurityEvents(ctx context.Context, apctx *appcontext.ContextInfo, customerID uuid.UUID, page, limit int) *contract.Response
}

type CustomerPinServiceImpl struct {
	pins *processor.CustomerPinProcessor
}

func NewCustomerPinService(pins *processor.CustomerPinProcessor) *CustomerPinServiceImpl {
	return &CustomerPinServiceImpl{pins: pins}
}

func (s *CustomerPinServiceImpl) Status(ctx context.Context, customerID uuid.UUID) *contract.Response {
	status, err := s.pins.Status(ctx, customerID)
	if err != nil {
		return PinErrorResponse(err)
	}
	return contract.BuildSuccessResponse(status)
}

func (s *CustomerPinServiceImpl) RequestOtp(ctx context.Context, customerID uuid.UUID, req *contract.RequestPinOtpRequest) *contract.Response {
	otp, err := s.pins.RequestOtp(ctx, customerID, req.Purpose)
	if err != nil {
		return PinErrorResponse(err)
	}
	return contract.BuildSuccessResponse(otp)
}

func (s *CustomerPinServiceImpl) CreatePin(ctx context.Context, customerID uuid.UUID, req *contract.CreateCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response {
	if err := s.pins.CreatePin(ctx, customerID, req.OtpToken, req.OtpCode, req.Pin, req.ConfirmPin, info); err != nil {
		return PinErrorResponse(err)
	}
	return s.Status(ctx, customerID)
}

func (s *CustomerPinServiceImpl) ChangePin(ctx context.Context, customerID uuid.UUID, req *contract.ChangeCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response {
	if err := s.pins.ChangePin(ctx, customerID, req.OldPin, req.Pin, req.ConfirmPin, info); err != nil {
		return PinErrorResponse(err)
	}
	return s.Status(ctx, customerID)
}

func (s *CustomerPinServiceImpl) ResetPin(ctx context.Context, customerID uuid.UUID, req *contract.ResetCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response {
	if err := s.pins.ResetPin(ctx, customerID, req.OtpToken, req.OtpCode, req.Pin, req.ConfirmPin, info); err != nil {
		return PinErrorResponse(err)
	}
	return s.Status(ctx, customerID)
}

func (s *CustomerPinServiceImpl) RemovePin(ctx context.Context, apctx *appcontext.ContextInfo, customerID uuid.UUID, req *contract.RemoveCustomerPinRequest, info models.CustomerPinRequestInfo) *contract.Response {
	if err := s.pins.RemovePinByAdmin(ctx, apctx.OrganizationID, customerID, apctx.UserID, req.Reason, info); err != nil {
		return PinErrorResponse(err)
	}
	return contract.BuildSuccessResponse(map[string]interface{}{"message": "PIN removed; the customer has to create a new one"})
}

func (s *CustomerPinServiceImpl) ListSecurityEvents(ctx context.Context, apctx *appcontext.ContextInfo, customerID uuid.UUID, page, limit int) *contract.Response {
	events, err := s.pins.ListEvents(ctx, apctx.OrganizationID, customerID, page, limit)
	if err != nil {
		return PinErrorResponse(err)
	}
	return contract.BuildSuccessResponse(events)
}

// PinErrorResponse turns an error from a PIN-guarded action into a response the apps
// can act on. A *processor.PinError keeps its code (PIN_NOT_SET, PIN_INVALID,
// PIN_LOCKED, TRANSFER_BLOCKED) and puts the attempts left or the time it lifts in the
// response data. Other errors map to a validation or server error.
func PinErrorResponse(err error) *contract.Response {
	var pinErr *processor.PinError
	if errors.As(err, &pinErr) {
		data := map[string]interface{}{"code": pinErr.Code}
		switch pinErr.Code {
		case processor.PinErrInvalid:
			data["remaining_attempts"] = pinErr.RemainingAttempts
		case processor.PinErrLocked:
			data["locked_until"] = pinErr.Until
		case processor.PinErrTransferBlocked:
			data["transfer_blocked_until"] = pinErr.Until
		}
		return &contract.Response{
			Success: false,
			Data:    data,
			Errors:  []*contract.ResponseError{contract.NewResponseError(pinErr.Code, constants.CustomerPinServiceEntity, pinErr.Error())},
		}
	}

	code := constants.InternalServerErrorCode
	switch {
	case errors.Is(err, repository.ErrPinCustomerNotFound):
		code = constants.NotFoundErrorCode
	case errors.Is(err, processor.ErrPinOtpTooSoon):
		code = constants.TooManyRequestsErrorCode
	case errors.Is(err, processor.ErrInvalidPinInput),
		errors.Is(err, processor.ErrPinAlreadySet),
		errors.Is(err, processor.ErrPinOtpInvalid),
		errors.Is(err, processor.ErrPinNoPhone):
		code = constants.ValidationErrorCode
	}
	return contract.BuildErrorResponse([]*contract.ResponseError{
		contract.NewResponseError(code, constants.CustomerPinServiceEntity, err.Error()),
	})
}