function load(name)
    local file = fs.open(name, "r");
    if file ~= nil then
        local data = file.readAll();
        file.close();
        return textutils.unserialize(data);
    else
        return {}
    end
end

hasMon = false;
list = load("todoList");
i = 1;
len = 0;
if peripheral.isPresent("left") then
    hasMon = true;
    mon = peripheral.wrap("top");
    print("Monitor was found!");
    mon.clear();
    mon.setCursorPos(1,1);
end

function save(table, name)
    local file = fs.open(name, "w");
    file.write(textutils.serialize(table));
    file.close();
end



function nl()
    if hasMon == true then
    local x,y = mon.getCursorPos();
    mon.setCursorPos(1, y+1);
    end
end

function printm(str)
    if type(str) ~= "string" then return end
    mon.write(str);
    nl();
end

function drawScreen()
    if hasMon == true then
        mon.setCursorPos(1,1);
        mon.clear();
        for j = 1,len do
            printm(list[j]);
        end
    end
end

function add()
    print("Enter your task: ");
    listAns = read();
    print("\n");
    if type(listAns) == "string" then
        list[i] = " - " .. listAns;
        printm(list[i]);
        i = i +1;
        len = len +1;
    end
    save(list, "todoList");
end

function removeFromList(n)
    table.remove(list, n);
end

function remove()
    print("Which task would you like to remove?");
    removeAns = read();
    print("\n");
    if type(removeAns) == "string" then
        removeAns = tonumber(removeAns);
        if removeAns <= len then
            removeFromList(removeAns);
        end
    end
    drawScreen();
    save(list, "todoList");
end

function start()
    while true do
        print("What would you like to do?");
        print(" - Type \"add\" to add an item");
        print(" - Type \"remove\" to add an item");
        print(" - Type \"quit\" to save and quit");
        ans = read();
        if type(ans) == "string" then
            if ans == "add" then add() end
            if ans == "remove" then remove() end
            if ans == "quit" then
                printm("Goodbye!");
                os.shutdown();
            end
        end
    end
end

start();