include "primitives.alh"
include "io.alh"

String function instantiated_name(element : Element, original : String):
	if (original == ""):
		return cast_id2s(element)
	else:
		return original

Element function instantiate_bottom():
	// Just create a new node that serves as the basis for everything
	// We don't know anything about the model yet, so just create an empty one
	Element new_model

	// The actual root node of the model
	new_model = create_node()

	// Add an empty model and empty type mapping
	dict_add(new_model, "model", create_node())
	dict_add(new_model, "type_mapping", create_node())

	// Return the created model
	return new_model

String function model_add_node(model : Element, name : String):
	// Adds a new node to the specified model with the desired name
	// This is a bottom operation, as it doesn't take any type
	Element new_node
	String actual_name

	new_node = create_node()
	actual_name = instantiated_name(new_node, name)
	dict_add(model["model"], actual_name, new_node)

	return actual_name

String function model_add_value(model : Element, name : String, value : Element):
	// Similar to model_add_node, but add a value as well
	String actual_name

	actual_name = instantiated_name(value, name)
	dict_add(model["model"], actual_name, value)

	return actual_name

String function model_add_edge(model : Element, name : String, source : String, destination : String):
	// Add an edge between the source and destination nodes
	// Nodes are specified using their string representation previously defined
	Element new_edge
	String actual_name
	
	new_edge = create_edge(model["model"][source], model["model"][destination])
	actual_name = instantiated_name(new_edge, name)
	dict_add(model["model"], actual_name, new_edge)

	return actual_name

Void function retype_model(model : Element, metamodel : Element):
	// Remove the type mapping and add a new one for the specified metamodel
	dict_delete(model, "type_mapping")
	dict_add(model, "type_mapping", create_node())
	dict_add(model, "metamodel", metamodel)
	return

Void function retype(model : Element, element : String, type : String):
	// Retype a model, deleting any previous type the element had
	// The type string is evaluated in the metamodel previously specified
	if (dict_in_node(model["type_mapping"], model["model"][element])):
		dict_delete(model["type_mapping"], model["model"][element])
	dict_add(model["type_mapping"], model["model"][element], model["metamodel"]["model"][type])

	return

Element function instantiate_model(metamodel : Element):
	// Instantiate a model
	// Basically create an untyped model and retype it
	Element model
	model = instantiate_bottom()
	retype_model(model, metamodel)
	return model

String function instantiate_node(model : Element, type_name : String, instance_name : String):
	// Create a node typed by a node from the metamodel
	// Basically create a node and type it immediately
	String actual_name

	actual_name = model_add_node(model, instance_name)
	retype(model, instance_name, type_name)

	return actual_name

Void function instantiate_attribute(model : Element, element : String, attribute : String, value : Element):
	// Instantiate an attribute of something that needs to be instantiated
	// Actually a bit more difficult than all the rest, as we need to find the attribute to instantiate
	Element elem
	Element type
	Element attr_type

	elem = model["model"][element]
	type = model["type_mapping"][elem]
	//attr_type = find_attribute(model, type, attribute)
	instantiate_link(model, attr_type, "", elem, value)

	return

String function instantiate_link(model : Element, type : String, name : String, source : String, destination : String):
	// Create a typed link between two nodes
	String actual_name

	actual_name = model_add_edge(model, name, source, destination)
	retype(model, actual_name, type)

	return actual_name

Void function instantiate_named_value(model : Element, type : String, name : String, source : String, destination : Element):
	// Special helper function to create an edge and name it
	String actual_name

	actual_name = instantiate_link(model, type, "", source, destination)
	instantiate_attribute(model, model["model"][actual_name], "name", name)

	return

Void function instantiate_named(model : Element, type : String, name : String, source : String, destination : String):
	// Special helper function to create an edge and name it
	instantiate_named(model, type, name, source, model["model"][destination])

	return

Void function define_inheritance(model : Element, inheritance_name : String):
	// Set the inheritance link to the one defined in our own metamodel, given by the specified name
	dict_add(model, "inheritance", model["metamodel"]["model"][inheritance_name])

	return

Void function construct_model():
	String command
	log("Enter modelling constructs!")
	while (True):
		command = input()

		if (command == "instantiate_bottom"):
			output(instantiate_bottom())
		elif (command == "add_node"):
			model_add_node(input(), input())
		elif (command == "add_value"):
			model_add_value(input(), input(), input())
		elif (command == "add_edge"):
			model_add_edge(input(), input(), input(), input())
		elif (command == "exit"):
			return
		elif (command == "retype_model"):
			retype_model(input(), input())
		elif (command == "retype"):
			retype(input(), input(), input())
		elif (command == "instantiate_model"):
			output(instantiate_model(input()))
		elif (command == "instantiate_attribute"):
			instantiate_named(input(), input(), input(), input(), input())
		elif (command == "define_inheritance"):
			define_inheritance(input(), input())
		else:
			log("Modelling error: did not understand command " + command)