package notification

import (
	"context"
	"errors"
	"fmt"

	"tm/pkg/logger"
	"tm/pkg/response"
)

// NotificationService defines the interface for notification business logic
type NotificationService interface {
	Create(ctx context.Context, req *NotificationRequest) (*NotificationResponse, error)
	Update(ctx context.Context, id string, req *NotificationRequest) (*NotificationResponse, error)
	Get(ctx context.Context, id string) (*NotificationResponse, error)
	Search(ctx context.Context, req *SearchForm, pagination *response.Pagination) (*NotificationsResponse, error)
	Delete(ctx context.Context, id string) error
}

// notificationService implements NotificationService interface
type notificationService struct {
	repository NotificationRepository
	logger     logger.Logger
}

// NewNotificationService creates a new notification service
func NewNotificationService(
	repository NotificationRepository,
	logger logger.Logger,
) NotificationService {
	return &notificationService{
		repository: repository,
		logger:     logger,
	}
}

// Create creates a single notification
func (s *notificationService) Create(ctx context.Context, req *NotificationRequest) (*NotificationResponse, error) {
	s.logger.Info("Creating notification", map[string]interface{}{
		"recipient": req.Recipient,
		"type":      req.Type,
		"priority":  req.Priority,
	})

	// Create notification entity
	notification := &Notification{
		Recipient:   req.Recipient,
		Tender:      req.Tender,
		Channels:    req.Channels,
		Type:        req.Type,
		Priority:    req.Priority,
		Title:       req.Title,
		Description: req.Description,
		Link:        req.Link,
		Status:      DeliveryStatusPending,
		Schedule: Schedule{
			Time: req.Schedule.Time,
		},
	}

	// Create notification in repository
	if err := s.repository.Create(ctx, notification); err != nil {
		s.logger.Error("Failed to create notification", map[string]interface{}{
			"recipient": req.Recipient,
			"error":     err.Error(),
		})
		return nil, fmt.Errorf("failed to create notification")
	}

	s.logger.Info("Notification created", map[string]interface{}{
		"notification_id": notification.ID,
		"recipient":       req.Recipient,
		"channels":        req.Channels,
	})

	return notification.ToResponse(), nil
}

// Update updates a notification
func (s *notificationService) Update(ctx context.Context, id string, req *NotificationRequest) (*NotificationResponse, error) {
	s.logger.Info("Updating notification", map[string]interface{}{
		"notification_id": id,
	})

	notification, err := s.repository.Get(ctx, id)
	if err != nil {
		s.logger.Error("Failed to get notification", map[string]interface{}{
			"notification_id": id,
			"error":           err.Error(),
		})
		return nil, fmt.Errorf("failed to get notification")
	}

	if notification.Status == DeliveryStatusSent {
		return nil, fmt.Errorf("notification already sent")
	}

	// update notification fields
	notification.Recipient = req.Recipient
	notification.Tender = req.Tender
	notification.Channels = req.Channels
	notification.Type = req.Type
	notification.Priority = req.Priority
	notification.Title = req.Title
	notification.Description = req.Description
	notification.Link = req.Link
	notification.Schedule = Schedule{
		Time: req.Schedule.Time,
	}
	notification.Status = DeliveryStatusPending

	// update notification in repository
	if err := s.repository.Update(ctx, notification); err != nil {
		s.logger.Error("Failed to update notification", map[string]interface{}{
			"notification_id": id,
			"error":           err.Error(),
		})
		return nil, fmt.Errorf("failed to update notification")
	}

	s.logger.Info("Notification updated", map[string]interface{}{
		"notification_id": id,
		"recipient":       req.Recipient,
		"channels":        req.Channels,
	})

	return notification.ToResponse(), nil
}

// Get gets a notification
func (s *notificationService) Get(ctx context.Context, id string) (*NotificationResponse, error) {
	s.logger.Info("Getting notification", map[string]interface{}{
		"notification_id": id,
	})

	notification, err := s.repository.Get(ctx, id)
	if err != nil {
		s.logger.Error("Failed to get notification", map[string]interface{}{
			"notification_id": id,
			"error":           err.Error(),
		})
		return nil, fmt.Errorf("failed to get notification")
	}

	return notification.ToResponse(), nil
}

// Search searches for notifications
func (s *notificationService) Search(ctx context.Context, req *SearchForm, pagination *response.Pagination) (*NotificationsResponse, error) {
	notifications, total, err := s.repository.Search(ctx, req, pagination)
	if err != nil {
		s.logger.Error("Failed to search notifications", map[string]interface{}{
			"error": err.Error(),
		})
		return nil, errors.New("failed to search notifications")
	}

	var notificationResponses []*NotificationResponse
	for _, notification := range notifications {
		notificationResponses = append(notificationResponses, notification.ToResponse())
	}

	return &NotificationsResponse{
		Notifications: notificationResponses,
		Meta:          pagination.Response(total),
	}, nil
}

// Delete deletes a notification
func (s *notificationService) Delete(ctx context.Context, id string) error {
	s.logger.Info("Deleting notification", map[string]interface{}{
		"notification_id": id,
	})

	notification, err := s.repository.Get(ctx, id)
	if err != nil {
		s.logger.Error("Failed to get notification", map[string]interface{}{
			"notification_id": id,
			"error":           err.Error(),
		})
		return fmt.Errorf("failed to get notification")
	}

	if notification.Status == DeliveryStatusSent {
		return fmt.Errorf("notification already sent")
	}

	err = s.repository.Delete(ctx, id)
	if err != nil {
		s.logger.Error("Failed to delete notification", map[string]interface{}{
			"notification_id": id,
			"error":           err.Error(),
		})
		return err
	}

	return nil
}