modelverse/core/core_algorithm.alc

include "modelling.alh"
include "library.alh"

Element core = ?

Void function main():
	// Initialize the Core Formalism
	String core_location
	String admin_group
	String admin_user

	core_location = "models/CoreFormalism"

	// Create the Model itself and make public
	core = instantiate_model(import_node(core_location))

	// Create admin group
	admin_group = instantiate_node(core, "Group", "")
	instantiate_attribute(core, admin_group, "name", "admin")

	// Create admin user
	admin_user = instantiate_node(core, "User", "")
	instantiate_attribute(core, admin_user, "name", get_username())
	instantiate_attribute(core, admin_user, "admin", True)

	// Create link between admin user and group
	instantiate_link(core, "ownedBy", "", admin_group, admin_user)
	instantiate_link(core, "belongsTo", "", admin_user, admin_group)

	// Add the core formalism already
	core_model = instantiate_node(core, "Model", "")
	instantiate_attribute(core, core_model, "name", "CoreFormalism")
	instantiate_attribute(core, core_model, "location", core_location)
	instantiate_attribute(core, core_model, "permissions", "330")

	// Make necessary links for the formalism to the owners
	instantiate_link(core, "group", "", core_model, admin_group)
	instantiate_link(core, "owner", "", core_model, admin_user)

	// Switch all new users to the user_function
	// This accesses the bootstrap level, so do not change this unless you know what you are doing
	Element root
	root = read_root()
	dict_del(root["__hierarchy"], "__IP")
	dict_add(root["__hierarchy"], "__IP", user_function)

	// Call this for ourselves as well
	user_function_skip_init(admin_user)

	// Done, so finish up
	// Admin user will have been deleted by the user_function as usual
	// Note that if there are no admin users left, it will be very difficult to manage, as nobody will have admin permissions!
	return !

Integer function get_relation_to_model(user_id : String, model_id : String):
		if (set_in(allAssociationDestinations(core, model_id, "owner"), user_id)):
			// We are the owner
			return 0!
		else:
			String group_id
			group_id = set_pop(allAssociationDestinations(core, model_id, "group"))
			if (set_in(allAssociationDestinations(core, user_id, "belongsTo"), group_id)):
				// We are in the owning group
				return 1!
			else:
				// We are not related whatsoever
				return 2!

Boolean function is_admin(user_id : String):
	if (read_attribute(core, user_id, "admin")):
		return True!
	else:
		return False!
	
Boolean function allow_read(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		// Check permissions
		String permission
		permission = string_get(read_attribute(core, model_id, "permissions"), get_relation_to_model(user_id, model_id))
		if (bool_or(permission == "1", permission == "3")):
			return True!
		else:
			return False!

Boolean function allow_write(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		// Check permissions
		String permission
		permission = string_get(read_attribute(core, model_id, "permissions"), get_relation_to_model(user_id, model_id))
		if (bool_or(permission == "2", permission == "3")):
			return True!
		else:
			return False!

Boolean function allow_change_metadata(user_id : String, model_id : String):
	if (is_admin(user_id)):
		// Is admin, so always allow
		return True!
	else:
		if (get_relation_to_model(user_id, model_id) == "0"):
			// Only owner can chmod
			return True!
		else:
			return False!

Void function user_function():
	// Now the username is bound to the task ID, so there is no problem
	// TODO check whether username isn't registered yet

	// Add user to Core Formalism
	String user_id
	user_id = instantiate_node(core, "User", "")
	instantiate_attribute(core, user_id, "name", get_username())
	instantiate_attribute(core, user_id, "admin", False)

	// Now call with user created
	user_function_skip_init(user_id)

	// User destroyed already, so just stop execution
	return !

String function get_model_id(name : String):
	Element models
	String model

	models = allInstances(core, "Model")
	while (read_nr_out(models) > 0):
		model = set_pop(models)
		if (read_attribute(core, model, "name") == name):
			return model!
	
	return ""!

Void function user_function_skip_init(user_id : String)
	Boolean do_continue
	String cmd

	do_continue = True

	output("Welcome to the Model Management Interface v2.0!")
	output("Use the 'help' command for a list of possible commands")

	while (do_continue):
		output("Ready for command...")
		cmd = input()
		if (cmd == "help"):
			output("Model operations")
			output("    model_add						-- Add a new model")
			output("    model_modify					-- Modify an existing model")
			output("    model_delete					-- [TODO] Delete a model and all related transformations")
			output("    model_list						-- List all models")
			output("    model_list_full					-- List all models with full info")
			output("")
			output("Transformation-specific operations")
			output("    transformation_add				-- TODO")
			output("    transformation_source_add		-- TODO")
			output("    transformation_source_delete	-- TODO")
			output("    transformation_target_add		-- TODO")
			output("    transformation_target_delete	-- TODO")
			output("    transformation_execute			-- TODO")
			output("")
			output("Model permission operations")
			output("    permission_modify				-- TODO")
			output("    permission_owner				-- TODO")
			output("    permission_group				-- TODO")
			output("")
			output("Group operations")
			output("    group_create					-- TODO")
			output("    group_delete					-- TODO")
			output("    group_owner						-- TODO")
			output("    group_join						-- TODO")
			output("    group_kick						-- TODO")
			output("")
			output("Admin operations")
			output("    admin_promote					-- Promote a user to admin status")
			output("    admin_demote					-- Demote a user to normal status")
			output("")
			output("General operations")
			output("    account_delete					-- Remove current user and revoke all permissions ")

		elif (cmd == "model_add"):
			// Model addition operation, which uses model upload commands of the compiler
			String name
			String type
			String location
			Element new_model

			output("Creating new model!")
			output("Model type?")
			type_id = get_model_id(input())
			if (type_id != ""):
				// Type exists
				if (allow_read(user_id, type_id)):
					// And is readable
					output("Model name?")
					name = input()
					if (get_model_id(name) == ""):
						// Model doesn't exist yet
						output("Waiting for model constructors...")
						// TODO update for access control
						new_model = construct_model(read_attribute(core, type_id, "location"))
						output("Model upload success!")
						location = "/models/" + cast_id2s(new_model)
						export_node(new_model, location)

						// Manage meta-info
						new_model_id = instantiate_node(core, "Model", "")
						instantiate_attribute(core, new_model_id, "name", name)
						instantiate_attribute(core, new_model_id, "location", location)
						instantiate_attribute(core, new_model_id, "permissions", "300")
						instantiate_link(core, "owner", "", new_model_id, user_id)
						instantiate_link(core, "instanceOf", "", new_model_id, type_id)
						output("Meta-info correctly set!")
					else:
						output("Model with that name already exists!")
				else:
					output("You are not allowed to read this type model!")
			else:
				output("Could not find type model!")

		elif (cmd == "model_modify"):
			// Model modify operation, which uses the mini_modify.alc operations, though with extensions for access control
			String model_id

			output("Which model do you want to modify?")
			model_id = get_model_id(input())

			if (model_id != ""):
				if (allow_read(user_id, model_id)):
					mini_modify(import_node(read_attribute(core, model_id, "location")), allow_write(user_id, model_id))
				else:
					output("You are not allowed to read this model!")
			else:
				output("Could not find model!")

		elif (cmd == "model_delete"):
			// Delete a model and all of its related transformations
			String model_id

			output("=================================================")
			output("WARNING: Deletion is a very destructive operation")
			output("         as it also deletes all transformations  ")
			output("         defined which make use of this model!   ")
			output("=================================================")

			output("")
			output("Currently not supported!")

		elif (cmd == "model_list"):
			// List all models
			Element models
			String m

			models = allInstances(core, "Model")
			while (read_nr_out(models) > 0):
				m = set_pop(models)
				output(("  " + (read_attribute(core, m, "name")) + " : ") + read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name"))

		elif (cmd == "model_list_full")
			// List all models with full info
			Element models
			String m
			String permissions
			String owner
			String group
			String name
			String type

			models = allInstances(core, "Model")
			while (read_nr_out(models) > 0):
				m = set_pop(models)
				permissions = read_attribute(core, m, "permissions")
				owner = read_attribute(core, set_pop(allAssociationDestinations(core, m, "owner")), "name")
				group = read_attribute(core, set_pop(allAssociationDestinations(core, m, "group")), "name")
				name = read_attribute(core, m, "name")
				size = read_nr_out(dict_read(import_node(read_attribute(core, m, "location")), "model"))
				type = read_attribute(core, set_pop(allAssociationDestinations(core, m, "instanceOf")), "name")
				output((((((((((("  " + permissions) + "  ") + owner) + " ") + group) + "    ") + size) + "   ") + name) + " : ") + type)

		elif (cmd == "admin_promote"):
			// Promote a user to admin status
			if (is_admin(user_id)):
				String other_user_id

				output("Which user do you want to promote?")
				other_user_id = get_user_id(input())
				if (other_user_id != ""):
					unset_attribute(core, other_user_id, "admin")
					instantiate_attribute(core, other_user_id, "admin", True)
					output("Permissions granted!")
				else:
					output("No such user!")
			else:
				output("Permission denied!")

		elif (cmd == "admin_demote"):
			// Demote a user to normal status
			if (is_admin(user_id)):
				String other_user_id

				output("Which user do you want to demote?")
				other_user_id = get_user_id(input())
				if (other_user_id != ""):
					unset_attribute(core, other_user_id, "admin")
					instantiate_attribute(core, other_user_id, "admin", False)
					output("Permissions revoked!")
				else:
					output("No such user!")
			else:
				output("Permission denied!")

		elif (cmd == "exit"):
			// Exit by actually removing the user and decoupling it from all of its models
			// Restarting with the same user name will NOT grant you access to anything of the previous user with that same name
			do_continue = False

	// Delete user from Core Formalism
	model_delete_element(core, user_id)
	output("Goodbye!")

	return !