package services

import (
	"fmt"

	"git.linuxforward.com/byop/byop-engine/dbstore"
	"git.linuxforward.com/byop/byop-engine/models"
)

// AppService handles business logic for apps
type AppService struct {
	store *dbstore.AppStore
}

// NewAppService creates a new AppService
func NewAppService(store *dbstore.AppStore) *AppService {
	return &AppService{store: store}
}

// CreateApp creates a new deployment app
func (s *AppService) CreateApp(app *models.App) error {
	// Validate app configuration
	if err := validateAppConfig(app.Config); err != nil {
		return fmt.Errorf("invalid app configuration: %w", err)
	}

	// Persist the app
	return s.store.Create(app)
}

// GetApp retrieves an app by ID
func (s *AppService) GetApp(id int64) (*models.App, error) {
	app, err := s.store.GetByID(id)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve app: %w", err)
	}
	return app, nil
}

// UpdateApp updates an existing app
func (s *AppService) UpdateApp(app *models.App) error {
	if app.ID == 0 {
		return fmt.Errorf("app ID is required for update")
	}

	// Check if app exists
	existingApp, err := s.store.GetByID(app.ID)
	if err != nil {
		return fmt.Errorf("failed to check if app exists: %w", err)
	}
	if existingApp == nil {
		return fmt.Errorf("app with ID %d not found", app.ID)
	}

	// Validate app configuration
	if err := validateAppConfig(app.Config); err != nil {
		return fmt.Errorf("invalid app configuration: %w", err)
	}

	return s.store.Update(app)
}

// DeleteApp deletes an app by ID
func (s *AppService) DeleteApp(id int64) error {
	// Check if app exists
	app, err := s.store.GetByID(id)
	if err != nil {
		return fmt.Errorf("failed to check if app exists: %w", err)
	}
	if app == nil {
		return fmt.Errorf("app with ID %d not found", id)
	}

	// Check if the app has deployments
	appWithDeployments, err := s.store.GetAppWithDeployments(id)
	if err != nil {
		return fmt.Errorf("failed to check app deployments: %w", err)
	}

	// Don't allow deletion if there are active deployments
	if len(appWithDeployments.Deployments) > 0 {
		return fmt.Errorf("cannot delete app with active deployments")
	}

	return s.store.Delete(id)
}

// ListApps retrieves all apps with optional filtering
func (s *AppService) ListApps(filter map[string]interface{}) ([]*models.App, error) {
	return s.store.List(filter)
}

// GetAppDeployments retrieves all deployments for an app
func (s *AppService) GetAppDeployments(id int64) ([]models.Deployment, error) {
	// First check if the app exists
	app, err := s.store.GetByID(id)
	if err != nil {
		return nil, fmt.Errorf("failed to check if app exists: %w", err)
	}
	if app == nil {
		return nil, fmt.Errorf("app with ID %d not found", id)
	}

	// Get app with deployments
	appWithDeployments, err := s.store.GetAppWithDeployments(id)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve app deployments: %w", err)
	}

	return appWithDeployments.Deployments, nil
}

// GetAppByVersion retrieves an app by name and version
func (s *AppService) GetAppByVersion(name, version string) (*models.App, error) {
	app, err := s.store.GetByVersion(name, version)
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve app: %w", err)
	}
	return app, nil
}

// validateAppConfig validates the app configuration
func validateAppConfig(config models.AppConfig) error {
	// Validate that at least one component is defined
	if len(config.Components) == 0 {
		return fmt.Errorf("app must define at least one component")
	}

	// Validate each component in the app
	for i, component := range config.Components {
		if component.Name == "" {
			return fmt.Errorf("component at index %d must have a name", i)
		}

		// Validate resource configuration
		if component.Resources.CPU == "" {
			return fmt.Errorf("component '%s' must specify CPU resources", component.Name)
		}
		if component.Resources.Memory == "" {
			return fmt.Errorf("component '%s' must specify memory resources", component.Name)
		}
	}

	// Add additional validation logic as needed

	return nil
}