package terraform

// ImportGraphBuilder implements GraphBuilder and is responsible for building
// a graph for importing resources into Terraform. This is a much, much
// simpler graph than a normal configuration graph.
type ImportGraphBuilder struct {
	// ImportTargets are the list of resources to import.
	ImportTargets []*ImportTarget

	// Providers is the list of providers supported.
	Providers []string
}

// Build builds the graph according to the steps returned by Steps.
func (b *ImportGraphBuilder) Build(path []string) (*Graph, error) {
	return (&BasicGraphBuilder{
		Steps:    b.Steps(),
		Validate: true,
	}).Build(path)
}

// Steps returns the ordered list of GraphTransformers that must be executed
// to build a complete graph.
func (b *ImportGraphBuilder) Steps() []GraphTransformer {
	steps := []GraphTransformer{
		// Add the import steps
		&ImportStateTransformer{Targets: b.ImportTargets},

		// Provider-related transformations
		&MissingProviderTransformer{Providers: b.Providers},
		&ProviderTransformer{},
		&DisableProviderTransformer{},
		&PruneProviderTransformer{},

		// Single root
		&RootTransformer{},

		// Insert nodes to close opened plugin connections
		&CloseProviderTransformer{},

		// Optimize
		&TransitiveReductionTransformer{},
	}

	return steps
}