local splashScreen = require('titlescreen.splash');
local modeSelectScreen = require('titlescreen.mode_select');

local screens = {
    splash = {
        screen = splashScreen
    },
    mode_select = {
        screen = modeSelectScreen
    }
}

local currentScreen = screens.splash;


local handleScreenResponse = function (res)
    if (res.eventType == 'switch') then
        if (not screens[res.toScreen]) then
            game.Log('Undefined screen ' .. res.toScreen, game.LOGGER_ERROR);
            return;
        end
        currentScreen = screens[res.toScreen]
    end
end

function render(deltaTime)
    handle_controller();
    
    local res = currentScreen.screen.render(deltaTime)
    if res then
        handleScreenResponse(res)
    end
end

function mouse_pressed(button)
    if true then return 0 end
    if (currentScreen.screen.onMousePressed) then
        currentScreen.screen.onMousePressed(button);
    end
end

function button_pressed(button)
    if (currentScreen.screen.onButtonPressed) then
        currentScreen.screen.onButtonPressed(button);
    end
end


function sign(x) return x > 0 and 1 or x < 0 and -1 or 0 end

function roundToZero(x)
    if x < 0 then
        return math.ceil(x)
    elseif x > 0 then
        return math.floor(x)
    else
        return 0
    end
end

function deltaKnob(delta)
    if math.abs(delta) > 1.5 * math.pi then
        return delta + 2 * math.pi * sign(delta) * -1
    end
    return delta
end

local lastKnobs = nil
local knobProgress = 0
function handle_controller()
    if (not currentScreen.screen.onKnobsChange) then
        return
    end

    if lastKnobs == nil then
        lastKnobs = {game.GetKnob(0), game.GetKnob(1)}
    else
        local newKnobs = {game.GetKnob(0), game.GetKnob(1)}

        knobProgress = knobProgress - deltaKnob(lastKnobs[1] - newKnobs[1]) *
                           1.2
        knobProgress = knobProgress - deltaKnob(lastKnobs[2] - newKnobs[2]) *
                           1.2

        lastKnobs = newKnobs

        if math.abs(knobProgress) > 1 then
            if (knobProgress < 0) then
                -- Negative
                currentScreen.screen.onKnobsChange(-1)
            else
                -- Positive
                currentScreen.screen.onKnobsChange(1)
            end
            knobProgress = knobProgress - roundToZero(knobProgress)
        end
    end
end