local ipairs, ItemStack, nodecore, include
    = ipairs, ItemStack, nodecore, include

rawset(_G, "nc_extended_rotating", {})
nc_extended_rotating.hud      = include("hud")
nc_extended_rotating.rotate   = include("rotate")
nc_extended_rotating.utility  = include("utility")  -- Depends on `rotate`.
nc_extended_rotating.entity   = include("entity")   -- Depends on `utility`.
nc_extended_rotating.registry = include("registry") -- Depends on `rotate` and `state` (late).
nc_extended_rotating.state    = include("state")    -- Depends on `registry`, `rotate` and `utility`.

do
    -- Do a quick check if we're using a compatible version of NodeCore.
    local lens_def = minetest.registered_nodes["nc_optics:lens"]
    if not lens_def.spindata then error("Requires NodeCore 966ed012 or later") end
end

-------------------------------------
-- Register Player Update Function --
-------------------------------------

local update_rotating_state = nc_extended_rotating.state.update_rotating_state
local update_player_hud     = nc_extended_rotating.hud.update_player_hud
local update_entity_hint    = nc_extended_rotating.entity.update_entity_hint

nodecore.register_playerstep({
    label = "nc_extended_rotating:update",
    action = function(player, data)
        local state = update_rotating_state(player, data)
        update_player_hud(player, state)
        update_entity_hint(player, state)
    end,
})

---------------------------------------
-- Register Rotatable NodeCore Nodes --
---------------------------------------

local register_rotatable = nc_extended_rotating.registry.register_rotatable;

-- Register lenses.
for _, lens_state in ipairs({ "", "_on", "_glow", "_glow_start" }) do
    register_rotatable("nc_optics:lens" .. lens_state) end

-- Register prisms.
for _, prism_state in ipairs({ "", "_on", "_gated" }) do
    register_rotatable("nc_optics:prism" .. prism_state) end

-- Register all existing and to-be-registered door panels.
nodecore.register_on_register_item({
    retroactive = true,
    func = function(name, def)
        -- This function is actually called BEFORE the item is registered with Minetest.
        -- Because of this, looking up the node definition by name does not work.
        -- Thankfully, the panel is registered before the door, and as such it already exists.
        if def.groups and def.groups.door then
            local panel = def.drop_in_place.name             -- The panel version of the door.
            local pin   = def.drop_non_silktouch or def.drop -- Dropped item is the door's pin.
            register_rotatable(panel, nil, function(_, _, _, item_stack)
                return ItemStack(item_stack):get_name() == pin end)
        end
    end,
})