package service

import (
	"context"
	"math"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/contract"
	"apskel-pos-be/internal/models"
	"apskel-pos-be/internal/processor"
	"apskel-pos-be/internal/transformer"

	"github.com/google/uuid"
)

type NotificationService interface {
	Send(ctx context.Context, req *contract.SendNotificationRequest, createdBy uuid.UUID) *contract.Response
	Broadcast(ctx context.Context, req *contract.BroadcastNotificationRequest, organizationID, createdBy uuid.UUID) *contract.Response
	MarkAsRead(ctx context.Context, receiverID, userID uuid.UUID) *contract.Response
	MarkAllAsRead(ctx context.Context, userID uuid.UUID) *contract.Response
	DeleteForUser(ctx context.Context, receiverID, userID uuid.UUID) *contract.Response
	ListForUser(ctx context.Context, req *contract.ListNotificationsRequest, userID uuid.UUID) *contract.Response
	GetByID(ctx context.Context, id uuid.UUID) *contract.Response
}

type NotificationServiceImpl struct {
	notificationProcessor processor.NotificationProcessor
}

func NewNotificationService(notificationProcessor processor.NotificationProcessor) *NotificationServiceImpl {
	return &NotificationServiceImpl{
		notificationProcessor: notificationProcessor,
	}
}

func (s *NotificationServiceImpl) Send(ctx context.Context, req *contract.SendNotificationRequest, createdBy uuid.UUID) *contract.Response {
	modelReq := &models.SendNotificationRequest{
		Title:          req.Title,
		Body:           req.Body,
		Type:           req.Type,
		Category:       req.Category,
		Priority:       req.Priority,
		ImageURL:       req.ImageURL,
		ActionURL:      req.ActionURL,
		NotifiableType: req.NotifiableType,
		NotifiableID:   req.NotifiableID,
		Data:           req.Data,
		ReceiverIDs:    req.ReceiverIDs,
		ScheduledAt:    req.ScheduledAt,
		ExpiredAt:      req.ExpiredAt,
		CreatedBy:      &createdBy,
	}

	resp, err := s.notificationProcessor.Send(ctx, modelReq)
	if err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(transformer.NotificationModelResponseToContract(resp))
}

func (s *NotificationServiceImpl) Broadcast(ctx context.Context, req *contract.BroadcastNotificationRequest, organizationID, createdBy uuid.UUID) *contract.Response {
	modelReq := &models.BroadcastNotificationRequest{
		Title:          req.Title,
		Body:           req.Body,
		Type:           req.Type,
		Category:       req.Category,
		Priority:       req.Priority,
		ImageURL:       req.ImageURL,
		ActionURL:      req.ActionURL,
		NotifiableType: req.NotifiableType,
		NotifiableID:   req.NotifiableID,
		Data:           req.Data,
		OrganizationID: organizationID,
		ScheduledAt:    req.ScheduledAt,
		ExpiredAt:      req.ExpiredAt,
		CreatedBy:      &createdBy,
	}

	resp, err := s.notificationProcessor.Broadcast(ctx, modelReq)
	if err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(transformer.NotificationModelResponseToContract(resp))
}

func (s *NotificationServiceImpl) MarkAsRead(ctx context.Context, receiverID, userID uuid.UUID) *contract.Response {
	resp, err := s.notificationProcessor.MarkAsRead(ctx, receiverID, userID)
	if err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(transformer.NotificationReceiverModelResponseToContract(resp))
}

func (s *NotificationServiceImpl) MarkAllAsRead(ctx context.Context, userID uuid.UUID) *contract.Response {
	if err := s.notificationProcessor.MarkAllAsRead(ctx, userID); err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(map[string]interface{}{"message": "All notifications marked as read"})
}

func (s *NotificationServiceImpl) DeleteForUser(ctx context.Context, receiverID, userID uuid.UUID) *contract.Response {
	if err := s.notificationProcessor.DeleteForUser(ctx, receiverID, userID); err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(map[string]interface{}{"message": "Notification deleted"})
}

func (s *NotificationServiceImpl) ListForUser(ctx context.Context, req *contract.ListNotificationsRequest, userID uuid.UUID) *contract.Response {
	modelReq := &models.ListNotificationsRequest{
		Page:   req.Page,
		Limit:  req.Limit,
		UserID: userID,
		IsRead: req.IsRead,
	}

	receivers, total, unreadCount, err := s.notificationProcessor.ListForUser(ctx, modelReq)
	if err != nil {
		errResp := contract.NewResponseError(constants.InternalServerErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	totalPages := int(math.Ceil(float64(total) / float64(req.Limit)))

	response := contract.ListNotificationsResponse{
		Notifications: transformer.NotificationReceiverModelResponsesToContracts(receivers),
		TotalCount:    total,
		UnreadCount:   unreadCount,
		Page:          req.Page,
		Limit:         req.Limit,
		TotalPages:    totalPages,
	}

	return contract.BuildSuccessResponse(response)
}

func (s *NotificationServiceImpl) GetByID(ctx context.Context, id uuid.UUID) *contract.Response {
	resp, err := s.notificationProcessor.GetByID(ctx, id)
	if err != nil {
		errResp := contract.NewResponseError(constants.NotFoundErrorCode, constants.NotificationServiceEntity, err.Error())
		return contract.BuildErrorResponse([]*contract.ResponseError{errResp})
	}

	return contract.BuildSuccessResponse(transformer.NotificationModelResponseToContract(resp))
}