gasmask.lua

-- gasmask.lua
-- Units wearing a gasmask are immune to SYN_INHALED syndromes.

local CALLBACK_ID = "gasmask"
local enabled = false

local eventful = require('plugins.eventful')
local syndromeUtil = require('syndrome-util')

local PROTECTED_HELMS = {
    ITEM_HELM_GASMASK1 = true,
    ITEM_HELM_GASMASK2 = true,
}

local function is_wearing_gasmask(unit)
    for _, inv_item in ipairs(unit.inventory) do
        if inv_item.mode == df.inv_item_role_type.Worn then
            local item = inv_item.item
            if item:getType() == df.item_type.HELM then
                local ok, sub_id = pcall(function()
                    return dfhack.items.getSubtypeDef(df.item_type.HELM, item:getSubtype()).id
                end)
                if ok and PROTECTED_HELMS[sub_id] then return true end
            end
        end
    end
    return false
end

local function on_syndrome(unit_id, syndrome_index)
    local unit = df.unit.find(unit_id)
    if not unit or not dfhack.units.isActive(unit) then return end
    local unit_syndrome = unit.syndromes.active[syndrome_index]
    if not unit_syndrome then return end
    local syn_id = unit_syndrome['type']
    local syn_def = df.syndrome.find(syn_id)
    if not syn_def or not syn_def.flags.SYN_INHALED then return end
    if is_wearing_gasmask(unit) then
        syndromeUtil.eraseSyndrome(unit, syn_id, true)
    end
end

local function enable()
    if enabled then print("[gasmask] Already enabled"); return end
    eventful.enableEvent(eventful.eventType.SYNDROME, 5)
    eventful.onSyndrome[CALLBACK_ID] = on_syndrome
    enabled = true
    print("[gasmask] Enabled - inhaled syndrome protection active")
end

local function disable()
    if not enabled then print("[gasmask] Already disabled"); return end
    eventful.onSyndrome[CALLBACK_ID] = nil
    enabled = false
    print("[gasmask] Disabled")
end

local function status()
    print(("[gasmask] Status: %s"):format(enabled and "ENABLED" or "DISABLED"))
end

local args = { ... }
local command = args[1] or "enable"
if     command == "enable"  then enable()
elseif command == "disable" then disable()
elseif command == "status"  then status()
else print("[gasmask] Usage: gasmask [enable|disable|status]")
end