package bin.srsc;

import kernel.log.Log;
import lib.KVStore;
import bin.srsc.PackageTypes;
import kernel.net.Package;
import kernel.ps.ProcessHandle;
import kernel.ps.Process;

/**
	The SiteRessourceController is responsible for the management of ressources on the site.
	It makes sure that ressources are have a unique id and that they are not duplicated.
	It also keeps track of the responsible NetID for each ressource. Kinda like a DNS.
**/
class SiteRessourceController implements Process {
	public static inline final SITE_CONTROLLER_RESSOURCE_MANAGER_PROTO:String = "srsc";

	private var handle:ProcessHandle;
	private var ressources:Map<String, NetworkID>;

	public function new() {}

	public function run(handle:ProcessHandle) {
		this.handle = handle;

		load();

		// Register proto
		kernel.net.Net.instance.registerProto(SITE_CONTROLLER_RESSOURCE_MANAGER_PROTO, this.handleMsg);
	}

	private function handleMsg(pkg:Package) {
		/*
			There are 3 types of messages:
			- Register a new ressource name 
			- Unregister a ressource name 
			- Get the responsible NetID for a ressource name 
		 */

		switch (pkg.data.type) {
			case "register":
				pkg.respond(handleRegister(pkg.data));
			case "unregister":
				pkg.respond(handleUnregister(pkg.data));
			case "get":
				pkg.respond(handleGet(pkg.data));
			default:
				handle.writeLine("Unknown message type: " + pkg.data.type);
		}
	}

	private function handleGet(data:GetRequest):GetResponse {
		var res = get(data.name);
		return {success: res != null, netID: res};
	}

	private function handleRegister(data:RegisterRequest):RegisterResponse {
		var res = register(data.name, data.netID);
		return {success: res};
	}

	private function handleUnregister(data:UnregisterRequest):UnregisterResponse {
		unregister(data.name);
		return {success: true};
	}

	public function register(name:String, netID:NetworkID):Bool {
		if (ressources.exists(name) && ressources.get(name) != netID) {
			return false;
		}

		ressources.set(name, netID);
		save();
		return true;
	}

	public function unregister(name:String) {
		if (ressources.exists(name)) {
			ressources.remove(name);
		}
		save();
	}

	public function get(name:String):Null<NetworkID> {
		return ressources.get(name);
	}

	private function load() {
		var store = KVStore.getStoreForClass();
		var data:Null<Map<String, NetworkID>> = store.get("ressources");

		if (data != null) {
			this.ressources = data;
		} else {
			this.ressources = new Map<String, NetworkID>();
		}
	}

	private function save() {
		var store = KVStore.getStoreForClass();
		store.set("ressources", this.ressources);
		store.save();
	}
}