local r = 1.5

local acid_puddles = {
    'acid-splash-fire-spitter-behemoth',
    'acid-splash-fire-spitter-big',
    'acid-splash-fire-spitter-medium',
    'acid-splash-fire-spitter-small',
    'acid-splash-fire-worm-behemoth',
    'acid-splash-fire-worm-big',
    'acid-splash-fire-worm-medium',
    'acid-splash-fire-worm-small'
}

local valid_enemies = {
    ['small-spitter'] = true,
    ['medium-spitter'] = true,
    ['big-spitter'] = true,
    ['behemoth-spitter'] = true,
    ['small-worm-turret'] = true,
    ['medium-worm-turret'] = true,
    ['big-worm-turret'] = true,
    ['behemoth-worm-turret'] = true
}

local function remove_puddles(event)
    local cause = event.cause
    if not cause then
        return true
    end
    if not cause.valid then
        return true
    end
    if valid_enemies[cause.name] then
        return true
    end
end

local function on_entity_damaged(event)
    if not remove_puddles(event) then
        return
    end
    local entity = event.entity
    if not entity or not entity.valid then
        return
    end
    local position = entity.position
    for _, puddle in pairs(entity.surface.find_entities_filtered({name = acid_puddles, area = {{position.x - r, position.y - r}, {position.x + r, position.y + r}}})) do
        puddle.destroy()
    end
end

local Event = require 'utils.event'
Event.add(defines.events.on_entity_damaged, on_entity_damaged)