package bin.exporter;

import kernel.peripherals.Peripherals.Peripheral;
import lib.KVStore;
import lib.exporter.Request;
import kernel.ps.ProcessHandle;
import lib.RessourceNames;
import lib.exporter.Export;
import kernel.ps.Process;
import kernel.net.Package;
import kernel.net.Net;
import kernel.net.Package.GenericPackage;

using tink.CoreApi;

class ResManager implements Process {
    private var handle:ProcessHandle;
    private var exports:Map<String,Export> = [];

    public function new() {}

    public function run(handle:ProcessHandle) {
        this.handle = handle;
        Net.registerProto("res",handlePackage);
        load();
    }

    public function register(id: String, export: Export): Promise<Noise>{
        if (exports.exists(id)){
            return Promise.reject(new Error("Ressource already exists: " + id));
        }

        return registerName(id).next((success)->{
            exports.set(id,export);
            persist();
            return null;
        });
    }

    private function handlePackage(pack: GenericPackage){
        var requestPack: Package<Request> = cast pack;
        var id = requestPack.data.id;

        if (!exports.exists(id)){
            requestPack.respond(lib.exporter.Response.NotFound);
            return;
        }

        var export = exports.get(id);
        var response = export.handleRequest(requestPack.data);

        requestPack.respond(response);
    }

    private function registerName(id: String){
        return RessourceNames.register(id, Net.networkID);
    }

    private function persist(){
        var store = new KVStore("export");

        var saveExports: Array<{name: String, addr: String, type: String}> = 
            [for (k => v in this.exports) {name: k, addr: v.getAddr(), type: v.getType()}];

        store.set("exports",saveExports);

        store.save();
    }

    private function load(){
        var store = new KVStore("export");

        var savedExports: Array<{name: String, addr: String, type: String}> = store.get("exports",[]);

        for (export in savedExports){
            var perph = Peripheral.getFromType(export.addr,export.type);

            if (perph == null){
                handle.writeLine('Could not load export: ${export.name} on ${export.addr}');
                continue;
            }

            // I dont know if cast is the best way to do this
            // But since we know that this is a IExportable we can do this (I think)
            exports.set(export.name, new Export(cast perph)); 

            handle.writeLine('Loaded export: ${export.name} on ${export.addr}');
        }

    }
}