SOCD Cleaner with Humanized Overlap

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

local cfg = UI.Schema({
    enabled = UI.Toggle(true, { label = "Enable SOCD" }),
    overlap_min = UI.Slider(20, { min = 0, max = 60, label = "Overlap Min", suffix = "ms", group = "Timing" }),
    overlap_max = UI.Slider(35, { min = 0, max = 100, label = "Overlap Max", suffix = "ms", group = "Timing" }),
})

-- Map opposite keys
local OPPOSITES = {
    A = "D", D = "A",
    W = "S", S = "W",
}

local held = {}      -- physical keys currently held
local virt = {}      -- virtual keys currently active (sent to HID)
local lastH = nil    -- last horizontal key pressed (for LKW resolution)
local lastV = nil    -- last vertical key pressed (for LKW resolution)

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

local function resolve(key1, key2, lastKey)
    -- Both keys held: send last-key-wins with humanized delay
    if held[key1] and held[key2] then
        sendVirtual(lastKey, true)
        local delay = Math.Random(cfg.overlap_min, math.max(cfg.overlap_min, cfg.overlap_max))
        if delay > 0 then
            Timer.After(delay, function()
                -- Check both still held (may have been released during delay)
                if held[key1] and held[key2] then
                    local otherKey = lastKey == key1 and key2 or key1
                    sendVirtual(otherKey, false)
                end
            end)
        else
            local otherKey = lastKey == key1 and key2 or key1
            sendVirtual(otherKey, false)
        end
    else
        -- Only one held: send it, release the other
        sendVirtual(key1, held[key1] or false)
        sendVirtual(key2, held[key2] or false)
    end
end

function OnDown(key)
    if not cfg.enabled or not OPPOSITES[key] then
        return true
    end

    held[key] = true

    -- Track last key pressed for each axis
    if key == "A" or key == "D" then
        lastH = key
    end
    if key == "W" or key == "S" then
        lastV = key
    end

    -- Resolve both axes independently
    resolve("A", "D", lastH)
    resolve("W", "S", lastV)

    return false
end

function OnUp(key)
    if not cfg.enabled or not OPPOSITES[key] then
        return true
    end

    held[key] = false

    -- Resolve both axes
    resolve("A", "D", lastH)
    resolve("W", "S", lastV)

    return false
end

function OnBlur()
    -- Release all virtual keys and reset state
    for key, _ in pairs(virt) do
        sendVirtual(key, false)
    end
    held = {}
    virt = {}
    lastH = nil
    lastV = nil
end