beacons/init.lua

-- Maximum number of light nodes above beacon (or 0 for no max)
local beacon_height = tonumber(minetest.settings:get("beacon_height")) or 0

local function get_node_under_light(pos)
    pos = table.copy(pos)
    local node = minetest.get_node(pos)
    local y_dist = 0
    while minetest.get_item_group(node.name, "beacon_light") ~= 0 and (beacon_height == 0 or y_dist <= beacon_height) do
        node = minetest.get_node(vector.subtract(pos, {x = 0, y = y_dist, z = 0}))
        y_dist = y_dist + 1
    end
    return node
end

local function beacon_on_construct(pos, color)
    local above = vector.add(pos, {x = 0, y = 1, z = 0})
    if get_node_under_light(pos).name == ("beacons:base_" .. color) and minetest.get_node(above).name == "air" then
        minetest.set_node(above, {name = "beacons:light_" .. color})
    end
end

local function beacon_on_destruct(pos, color)
    local above = vector.add(pos, {x = 0, y = 1, z = 0})
    if minetest.get_node(above).name == ("beacons:light_" .. color) then
        minetest.remove_node(above)
    end
end

local function beacon_on_timer(pos, color)
    beacon_on_construct(pos, color)
    if get_node_under_light(pos).name ~= ("beacons:base_" .. color) then
        minetest.remove_node(pos)
    end
    return true
end

local function make_on_construct(color)
    return function(pos)
        minetest.get_node_timer(pos):start(1)
        return beacon_on_construct(pos, color)
    end
end

local function make_on_destruct(color)
    return function(pos) 
        return beacon_on_destruct(pos, color)
    end
end

local function make_on_timer(color)
    return function(pos) 
        return beacon_on_timer(pos, color)
    end
end

local color_descs = {
    white = "White",
    red = "Red",
    yellow = "Yellow",
    green = "Green",
    cyan = "Cyan",
    blue = "Blue",
    magenta = "Magenta",
    orange = "Orange",
    violet = "Violet",
}

for color, color_desc in pairs(color_descs) do
    minetest.register_node("beacons:base_" .. color, {
        description = color_desc .. " Beacon",
        tiles = {"beacons_base_top.png", "beacons_base_bottom.png", "beacons_base_side.png"},
        color = color:gsub("_", ""),
        groups = {beacon_base = 1, cracky = 2},
        is_ground_content = false,
        paramtype = "light",
        on_rotate = function() end,
        
        on_construct = make_on_construct(color),
        on_destruct = make_on_destruct(color),
        on_timer = make_on_timer(color),
    })
    
    if minetest.get_modpath("default") then
        minetest.override_item("beacons:base_" .. color, {sounds = default.node_sound_metal_defaults()})
        
        if minetest.get_modpath("dye") then
            local color_group
            if color == "magenta" then
                color_group = "excolor_red_violet"
            else
                color_group = "excolor_" .. color
            end
            
            minetest.register_craft({
                output = "beacons:base_" .. color,
                recipe = {
                    {"default:steel_ingot", "group:" .. color_group, "default:steel_ingot",},
                    {"default:steel_ingot",      "default:meselamp", "default:steel_ingot",},
                    {"default:steel_ingot",   "default:steel_ingot", "default:steel_ingot",},
                },
            })
            
            minetest.register_craft({
                type = "shapeless",
                output = "beacons:base_" .. color,
                recipe = {"group:beacon_base", "group:" .. color_group},
            })
        end
    end
    
    minetest.register_node("beacons:light_" .. color, {
        description = color_desc .. " Beacon Light",
        drawtype = "plantlike",
        tiles = {"beacons_light.png"},
        color = color:gsub("_", ""),
        paramtype = "light",
        sunlight_propagates = true,
        light_source = minetest.LIGHT_MAX,
        walkable = false,
        pointable = false,
        diggable = false,
        buildable_to = true,
        floodable = false,
        drop = "",
        groups = {beacon_light = 1, not_in_creative_inventory = 1},
        damage_per_second = 1,
        post_effect_color = color,
        on_blast = function() end,
        
        on_construct = make_on_construct(color),
        on_destruct = make_on_destruct(color),
        on_timer = make_on_timer(color),
    })
end