-- File:     codersea/seashine.lua
-- Purpose:  CoderSea lit-stairs and lit-slabs support
-- Credits:  See "codersea.md"
-- Licenses: See "LICENSE"

-- ===================================================================
-- Notes.

-- This code implements lit-stairs and lit-slabs. These are similar to
-- stairs and slabs produced by the "stairsshine" mod,  but this  code
-- adds the ability to  turn lit-stairs and  lit-slabs  on and off  by
-- punching them.

-- ===================================================================

-- "stair" and "slab" register routines for CoderSea.  These are based
-- on standard code and "stairsshine". Credits to Kahrl and celeron55.

-- Nodes will be called codersea:shine_stair_<subname>
-- and shine_stair_SUBNAME_off.
--
function codersea.register_shine_stair (subname, recipeitem, groups,
images, description, sounds)

    local params = {
        description = description,
        drawtype = "nodebox",
        tiles = images,
        paramtype = "light",
        paramtype2 = "facedir",
        is_ground_content = true,
        groups = groups,
        sounds = sounds,
        node_box = {
            type = "fixed",
            fixed = {
                {-0.5, -0.5, -0.5, 0.5, 0, 0.5},
                {-0.5, 0, 0, 0.5, 0.5, 0.5},
            },
        },

        on_place = function (itemstack, placer, pointed_thing)
            if pointed_thing.type ~= "node" then
                return itemstack
            end

            local p0 = pointed_thing.under
            local p1 = pointed_thing.above
            local param2 = 0

            local placer_pos = placer:getpos()
            if placer_pos then
                local dir = {
                    x = p1.x - placer_pos.x,
                    y = p1.y - placer_pos.y,
                    z = p1.z - placer_pos.z
                }
                param2 = minetest.dir_to_facedir(dir)
            end

            if p0.y-1 == p1.y then
                param2 = param2 + 20
                if param2 == 21 then
                    param2 = 23
                elseif param2 == 23 then
                    param2 = 21
                end
            end

            return minetest.item_place (itemstack, placer,
                pointed_thing, param2)
        end,
    }

    local params_on = CloneTable (params)
    params_on.light_source = 14

    minetest.register_node (":codersea:shine_stair_"
        .. subname .. "_off" , params)
    minetest.register_node (":codersea:shine_stair_"
        .. subname , params_on)

    minetest.register_craft ({
        output = 'codersea:shine_stair_' .. subname .. ' 4',
        recipe = {
            { recipeitem , "" , "" } ,
            { recipeitem , recipeitem , "" } ,
            { recipeitem , recipeitem , recipeitem } ,
        },
    })

    -- Flipped recipe

    minetest.register_craft ({
        output = 'codersea:shine_stair_' .. subname .. ' 4' ,
        recipe = {
            { ""         , ""         , recipeitem } ,
            { ""         , recipeitem , recipeitem } ,
            { recipeitem , recipeitem , recipeitem } ,
        },
    })
end

-- ===================================================================

-- Nodes will be called codersea:slab_<subname>

function codersea.register_shine_slab (subname, recipeitem,
groups, images, description, sounds)

    local params = {
        description = description,
        drawtype = "nodebox",
        tiles = images,
        paramtype = "light",
        paramtype2 = "facedir",
        is_ground_content = true,
        groups = groups,
        sounds = sounds,

        node_box = {
            type  = "fixed" ,
            fixed = { -0.5, -0.5, -0.5, 0.5, 0, 0.5 } ,
        } ,

        on_place = function (itemstack, placer, pointed_thing)
            if pointed_thing.type ~= "node" then
                return itemstack
            end

            -- If it's being placed on an another similar one, replace it with
            -- a full block

            local slabpos = nil
            local slabnode = nil
            local p0 = pointed_thing.under
            local p1 = pointed_thing.above
            local n0 = minetest.get_node (p0)
            local n1 = minetest.get_node (p1)
            local param2 = 0

            local n0_is_upside_down =
                StartsWith (n0.name, "codersea:shine_slab") and
                (n0.param2 >= 20)

            if StartsWith (n0.name, "codersea:shine_slab") and
                not n0_is_upside_down and p0.y+1 == p1.y then
                slabpos = p0
                slabnode = n0
            elseif StartsWith (n1.name, "codersea:shine_slab") then
                slabpos = p1
                slabnode = n1
            end
            if slabpos then
                -- Remove the slab at slabpos
                minetest.remove_node(slabpos)
                -- Make a fake stack of a single item and try to place it
                local fakestack = ItemStack(recipeitem)
                fakestack:set_count(itemstack:get_count())

                pointed_thing.above = slabpos
                local success
                fakestack, success = minetest.item_place (fakestack,
                    placer, pointed_thing)

                -- If the item was taken from the fake stack,
                -- decrement original

                if success then
                    itemstack:set_count (fakestack:get_count())
                -- Else put old node back
                else
                    minetest.set_node (slabpos, slabnode)
                end
                return itemstack
            end

            -- Upside down slabs
            if p0.y-1 == p1.y then
                -- Turn into full block if pointing at a existing slab
                if n0_is_upside_down  then
                    -- Remove the slab at the position of the slab
                    minetest.remove_node (p0)
                    -- Make a fake stack of a single item and
                    -- try to place it

                    local fakestack = ItemStack (recipeitem)
                    fakestack:set_count (itemstack:get_count())

                    pointed_thing.above = p0
                    local success

                    fakestack, success =
                        minetest.item_place (fakestack, placer,
                            pointed_thing)

                    -- If the item was taken from the fake stack,
                    -- decrement original

                    if success then
                        itemstack:set_count (fakestack:get_count())
                    -- Else put old node back
                    else
                        minetest.set_node (p0, n0)
                    end
                    return itemstack
                end

                -- Place upside down slab
                param2 = 20
            end

            -- If pointing at the side of a upside-down slab
            if n0_is_upside_down and p0.y+1 ~= p1.y then
                param2 = 20
            end

            return minetest.item_place (itemstack, placer,
                pointed_thing, param2)
        end ,
    }

    local params_on = CloneTable (params)
    params_on.light_source = 14

    minetest.register_node (":codersea:shine_slab_"
        .. subname .. "_off", params)

    minetest.register_node (":codersea:shine_slab_"
        .. subname, params_on)

    minetest.register_craft ({
        output = 'codersea:shine_slab_' .. subname .. ' 6' ,
        recipe = {
            { recipeitem , recipeitem , recipeitem} ,
        },
    })
end

-- ===================================================================

-- Nodes will be called codersea:{stair,slab}_<subname>

function codersea.register_shine  (subname , recipeitem ,
    groups , images , desc_stair , desc_slab , sounds)
    codersea.register_shine_stair (subname , recipeitem ,
        groups , images , desc_stair , sounds)
    codersea.register_shine_slab  (subname , recipeitem ,
        groups , images , desc_slab  , sounds)
end

-- ===================================================================

local on_shine_puncher = function (pos, node, puncher)
    local oldname = node.name
    local newname

    if not StartsWith (oldname, "codersea:shine_") then return end
    if EndsWith (oldname, "_off") then
        newname = oldname:gsub ("_off", "")
    else
        newname = oldname .. "_off"
    end

    minetest.set_node (pos, { name=newname })
    nodeupdate (pos)
end

-- ===================================================================

minetest.register_on_punchnode (on_shine_puncher)