-- Array of controller modes. We will switch
-- between the three of these randomly
local mode = {"P1", "P2", "ZEN"}
local current = mode[1]

-- Pre-made array for resetting the P1 joypad
local reset = joypad.get(1)
for k,v in pairs(reset) do
    reset[k] = ''
end

-- Seed randomness when we start
math.randomseed(os.time())

event.onframestart( function()
    local p1 = joypad.get(1)
    local p2 = joypad.get(2)
    local output = {}

    if current == "P1" then
        output = p1
    elseif current == "P2" then
        output = p2
    else
        output = intersection(p1, p2)
    end

    gui.drawText(0,0, current)
--  gui.drawText(0,15, dump(output))
    joypad.set(output,1)
end)

event.onframeend( function()
    joypad.set(reset, 1)
end)

function intersection(p1, p2)
    local ret = {}
    for k,v in pairs(p1) do
        ret[k] = p1[k] and p2[k]
    end
    return ret
end

-- Print all pressed buttons
function dump(o)
    local s = ''
    for k,v in pairs(o) do
       if v then s = s .. tostring(k) .. ' ' end
    end
    return s
  end

--------------------------------------
--             Main loop            --
--------------------------------------
while true do
    -- Switch mode randomly twice a second
    -- This might become the same mode as we
    -- already had
    if emu.framecount() % 30 == 0 then
        current = mode[ math.random(1,3) ]
    end

    emu.frameadvance()
end