-module(helloworld).
-export([start_fridge/0, fridge/0, store/2, take/2, main/0]).

% Main function to start the fridge and interact with it.
main() ->
    % Start the fridge process.
    FridgePid = start_fridge(),

    % Store some items in the fridge.
    store(FridgePid, apple),
    store(FridgePid, banana),
    store(FridgePid, carrot),

    % Try to take some items.
    take(FridgePid, banana),
    take(FridgePid, apple),

    % Attempt to take an item that is not in the fridge.
    take(FridgePid, orange),

    % End the simulation by sending terminate to the fridge process.
    FridgePid ! terminate.

% Start the fridge process.
start_fridge() ->
    spawn(helloworld, fridge, []).

% Fridge process function.
fridge() ->
    fridge_loop([]).

% Recursive loop to maintain state of the fridge (list of stored items).
fridge_loop(Items) ->
    receive
        {store, Item} ->
            % Add the item to the list of stored items and continue looping.
            fridge_loop([Item | Items]);
        {take, Item} ->
            % Check if the item is in the fridge.
            case lists:member(Item, Items) of
                true ->
                    % Remove the item from the list and continue looping.
                    NewItems = lists:delete(Item, Items),
                    sender ! {taken, Item}, % Confirm item has been taken
                    fridge_loop(NewItems);
                false ->
                    % If the item is not in the fridge, do nothing.
                    sender ! {error, not_found},
                    fridge_loop(Items)
            end;
        terminate ->
            % Terminate the fridge process.
            ok
    end.

% Send a message to store an item in the fridge.
store(FridgePid, Item) ->
    FridgePid ! {store, Item}.

% Send a message to take an item from the fridge.
take(FridgePid, Item) ->
    FridgePid ! {take, Item},
    receive
        {taken, Item} ->
            io:format("Item taken: ~p~n", [Item]);
        {error, not_found} ->
            io:format("Error: Item not found~n")
    end.