package core

import (
	"backea/internal/backup/models"
	"backea/internal/backup/strategy"
	"backea/internal/logging"
	"backea/internal/mail"
	"context"
	"os"
	"time"
)

type Service struct {
	Name      string
	Directory string
	Strategy  strategy.Strategy
	Mailer    *mail.Mailer
	logger    *logging.Logger
}

func NewService(name string, directory string, strategy strategy.Strategy, mailer *mail.Mailer) *Service {
	return &Service{
		Name:      name,
		Directory: directory,
		Strategy:  strategy,
		Mailer:    mailer,
		logger:    logging.GetLogger(),
	}
}

func (s *Service) Backup(ctx context.Context) error {
	s.logger.Info("Backing up service: %s", s.Name)
	startTime := time.Now()

	if _, err := os.Stat(s.Directory); os.IsNotExist(err) {
		return NewBackupError("directory does not exist: "+s.Directory, nil)
	}

	if err := s.Strategy.Execute(ctx, s.Name, s.Directory); err != nil {
		if s.Mailer != nil {
			s.Mailer.SendErrorNotification(s.Name, err)
		}
		return NewBackupError("backup failed for "+s.Name, err)
	}

	duration := time.Since(startTime)
	s.logger.Info("Backup completed for %s in %v", s.Name, duration)

	if s.Mailer != nil {
		s.Mailer.SendSuccessNotification(s.Name, duration)
	}
	return nil
}

func (s *Service) GetBackupInfos(ctx context.Context) ([]models.BackupInfo, error) {
	infos, err := s.Strategy.ListBackups(ctx, s.Name)
	if err != nil {
		return nil, NewBackupError("failed to list backups for "+s.Name, err)
	}
	return infos, nil
}

func (s *Service) GetStorageUsage(ctx context.Context) (*models.StorageUsageInfo, error) {
	usage, err := s.Strategy.GetStorageUsage(ctx, s.Name)
	if err != nil {
		return nil, NewBackupError("failed to get storage usage for "+s.Name, err)
	}
	return usage, nil
}

func (s *Service) RestoreBackup(ctx context.Context, backupID string) error {
	s.logger.Info("Restoring backup %s for service %s", backupID, s.Name)

	if err := s.Strategy.RestoreBackup(ctx, backupID, s.Name); err != nil {
		return NewBackupError("failed to restore backup "+backupID+" for "+s.Name, err)
	}
	return nil
}