SOCD Cleaner Lua Script

-- rebind: min_sdk=0.1.0 tick_rate=8000
-- rebind: name=SOCD Cleaner

local cfg = UI.Schema({
    enabled = UI.Toggle(true, { label = "Enable SOCD" }),
    mode = UI.Select("Last Input", { "Last Input", "Neutral" }, { label = "Conflict Mode" }),
    delay = UI.Slider(20, { min = 0, max = 100, label = "Overlap Delay", suffix = "ms", group = "Advanced" }),
})

-- Define opposing key pairs
local PAIRS = {
    { "A", "D" },
    { "W", "S" },
    { "Left", "Right" },
    { "Up", "Down" },
}

local held = {}
local virt = {}
local lastInput = {}

local function setVirt(key, state)
    if virt[key] == state then return end
    if state then
        HID.Down(key)
    else
        HID.Up(key)
    end
    virt[key] = state
end

local function resolveConflict(key1, key2)
    local h1 = held[key1] or false
    local h2 = held[key2] or false

    if cfg.mode == "Neutral" then
        -- Both pressed = release both
        if h1 and h2 then
            setVirt(key1, false)
            setVirt(key2, false)
            return
        end
    else
        -- Last Input mode: the most recently pressed key wins
        if h1 and h2 then
            local last = lastInput[key1] or lastInput[key2] or key1
            setVirt(key1, last == key1)
            setVirt(key2, last == key2)

            -- If delay is set, implement humanised overlap
            if cfg.delay > 0 and last == key1 then
                Timer.After(cfg.delay, function()
                    if held[key1] and held[key2] then
                        setVirt(key2, false)
                    end
                end)
            elseif cfg.delay > 0 and last == key2 then
                Timer.After(cfg.delay, function()
                    if held[key1] and held[key2] then
                        setVirt(key1, false)
                    end
                end)
            end
            return
        end
    end

    -- One or neither pressed: pass through
    setVirt(key1, h1)
    setVirt(key2, h2)
end

function OnDown(key)
    if not cfg.enabled then return true end

    -- Check if this key is part of any pair
    for _, pair in ipairs(PAIRS) do
        if key == pair[1] or key == pair[2] then
            held[key] = true
            lastInput[pair[1]] = System.Time()
            lastInput[pair[2]] = System.Time()
            resolveConflict(pair[1], pair[2])
            return false -- block physical input, we control output
        end
    end

    return true
end

function OnUp(key)
    if not cfg.enabled then return true end

    for _, pair in ipairs(PAIRS) do
        if key == pair[1] or key == pair[2] then
            held[key] = false
            resolveConflict(pair[1], pair[2])
            return false
        end
    end

    return true
end

function OnBlur()
    -- Release all virtual keys on blur
    for key, _ in pairs(virt) do
        setVirt(key, false)
    end
    held = {}
    virt = {}
    lastInput = {}
end

function OnStop()
    OnBlur()
end