-- function to safely remove climbable air
local function remove_air(pos, oldnode)
    local dir = minetest.facedir_to_dir(oldnode.param2)
    local airpos = vector.subtract(pos, dir)

    local north_node = minetest.get_node({x = airpos.x, y = airpos.y, z = airpos.z+1})
    local south_node = minetest.get_node({x = airpos.x, y = airpos.y, z = airpos.z-1})
    local east_node = minetest.get_node({x = airpos.x+1, y = airpos.y, z = airpos.z})
    local west_node = minetest.get_node({x = airpos.x-1, y = airpos.y, z = airpos.z})

    local keep_air =
        (minetest.get_item_group(north_node.name, "handholds") == 1 and
        north_node.param2 == 0) or
        (minetest.get_item_group(south_node.name, "handholds") == 1 and
        south_node.param2 == 2) or
        (minetest.get_item_group(east_node.name, "handholds") == 1 and
        east_node.param2 == 1) or
        (minetest.get_item_group(west_node.name, "handholds") == 1 and
        west_node.param2 == 3)

    if not keep_air then
        minetest.set_node(airpos, {name = "air"})
    end
end


-- climbable air!
minetest.register_node("handholds:climbable_air", {
    description = "Air!",
    drawtype = "airlike",
    paramtype = "light",
    sunlight_propagates = true,
    walkable = false,
    pointable = false,
    diggable = false,
    climbable = true,
    drop = "",
    groups = {not_in_creative_inventory = 1}
})


-- handholds nodes
minetest.register_node("handholds:stone", {
    description = "Stone",
    tiles = {
        "default_stone.png", "default_stone.png",
        "default_stone.png", "default_stone.png",
        "default_stone.png", "default_stone.png^handholds_holds.png"
    },
    paramtype2 = "facedir",
    groups = {cracky = 3, stone = 1, not_in_creative_inventory = 1, handholds = 1},
    drop = 'default:cobble',
    sounds = default.node_sound_stone_defaults(),
    after_destruct = function(pos, oldnode)
        remove_air(pos, oldnode)
    end,
})

minetest.register_node("handholds:desert_stone", {
    description = "Stone",
    tiles = {
        "default_desert_stone.png", "default_desert_stone.png",
        "default_desert_stone.png", "default_desert_stone.png",
        "default_desert_stone.png", "default_desert_stone.png^handholds_holds.png"
    },
    paramtype2 = "facedir",
    groups = {cracky = 3, stone = 1, not_in_creative_inventory = 1, handholds = 1},
    drop = 'default:desert_cobble',
    sounds = default.node_sound_stone_defaults(),
    after_destruct = function(pos, oldnode)
        remove_air(pos, oldnode)
    end,
})

minetest.register_node("handholds:sandstone", {
    description = "Stone",
    tiles = {
        "default_sandstone.png", "default_sandstone.png",
        "default_sandstone.png", "default_sandstone.png",
        "default_sandstone.png", "default_sandstone.png^handholds_holds.png"
    },
    paramtype2 = "facedir",
    groups = {cracky = 3, stone = 1, not_in_creative_inventory = 1, handholds = 1},
    drop = 'default:sandstone',
    sounds = default.node_sound_stone_defaults(),
    after_destruct = function(pos, oldnode)
        remove_air(pos, oldnode)
    end,
})

minetest.register_node("handholds:ice", {
    description = "Stone",
    tiles = {
        "default_ice.png", "default_ice.png",
        "default_ice.png", "default_ice.png",
        "default_ice.png", "default_ice.png^handholds_holds.png"
    },
    paramtype2 = "facedir",
    groups = {
        cracky = 3, puts_out_fire = 1, cools_lava = 1,
        not_in_creative_inventory = 1, handholds = 1
    },
    drop = 'default:ice',
    sounds = default.node_sound_glass_defaults(),
    after_destruct = function(pos, oldnode)
        remove_air(pos, oldnode)
    end,
})


-- handholds tool
minetest.register_tool("handholds:climbing_pick", {
    description = "Climbing Pick",
    inventory_image = "handholds_tool.png",
    sound = {breaks = "default_tool_breaks"},
    on_use = function(itemstack, player, pointed_thing)
        if not pointed_thing or
                pointed_thing.type ~= "node" or
                minetest.is_protected(pointed_thing.under, player:get_player_name()) or
                minetest.is_protected(pointed_thing.above, player:get_player_name()) or
                pointed_thing.under.y + 1 == pointed_thing.above.y or
                pointed_thing.under.y - 1 == pointed_thing.above.y then
            return
        end

        local node_def =
            minetest.registered_nodes[minetest.get_node(pointed_thing.above).name]
        if not node_def or not node_def.buildable_to then
            return
        end

        local node_name = minetest.get_node(pointed_thing.under).name
        local rotation = minetest.dir_to_facedir(
            vector.subtract(pointed_thing.under, pointed_thing.above))

        if node_name == "default:stone" then
            minetest.set_node(pointed_thing.under,
                {name = "handholds:stone", param2 = rotation})
        elseif node_name == "default:desert_stone" then
            minetest.set_node(pointed_thing.under,
                {name = "handholds:desert_stone", param2 = rotation})
        elseif node_name == "default:sandstone" then
            minetest.set_node(pointed_thing.under,
                {name = "handholds:sandstone", param2 = rotation})
        elseif node_name == "default:ice" then
            minetest.set_node(pointed_thing.under,
                {name = "handholds:ice", param2 = rotation})
        else
            return
        end

        minetest.set_node(pointed_thing.above, {name = "handholds:climbable_air"})
        minetest.sound_play(
            "default_dig_cracky",
            {pos = pointed_thing.above, gain = 0.5, max_hear_distance = 8}
        )

        if not minetest.setting_getbool("creative_mode") then
            local wdef = itemstack:get_definition()
            itemstack:add_wear(256)
            if itemstack:get_count() == 0 and wdef.sound and wdef.sound.breaks then
                minetest.sound_play(wdef.sound.breaks,
                    {pos = pointed_thing.above, gain = 0.5})
            end
            return itemstack
        end
    end
})

minetest.register_craft({
    output = "handholds:climbing_pick",
    recipe = {
        {'default:diamond', 'default:diamond', 'default:diamond'},
        {'group:stick', '', ''},
        {'group:stick', '', ''},
    },
})