minetest antifrief

-- ANTI GRIEF by rnd
-- Copyright 2016 rnd

----------------------------------------------------------------------------
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.

-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.

-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.
----------------------------------------------------------------------------


-- prevents placing of lava/liquid sources or buckets above 0


--water
--bucket:bucket_water

function prevent_place_above(name)

    local old_on_place=minetest.registered_craftitems[name];--.on_place;
    local old_after_place_node = minetest.registered_nodes[name];--.after_place_node;
    --after_place_node = func(pos, placer, itemstack, pointed_thing)

    if old_on_place and old_on_place.on_place then
        old_on_place=old_on_place.on_place;
        minetest.registered_craftitems[name].on_place=function(itemstack, placer, pointed_thing)
            local pos = pointed_thing.above
            if pos.y>0 then
                minetest.log("action","ANTI GRIEF " .. placer:get_player_name() .. " tried to place " .. name .. " at " .. minetest.pos_to_string(pos));
                return itemstack
            else
                return old_on_place(itemstack, placer, pointed_thing)
            end
        end
    return;
    end

    if old_after_place_node then

        old_after_place_node=old_after_place_node.after_place_node

        local table = minetest.registered_nodes[name];
        local table2 = {}
        for i,v in pairs(table) do
            table2[i] = v
        end

        table2.after_place_node=function(pos, placer, itemstack, pointed_thing)
            --after_place_node = func(pos, placer, itemstack, pointed_thing)
            local pos = pointed_thing.above
            if pos.y>0 then
                minetest.log("action","ANTI GRIEF " .. placer:get_player_name() .. " tried to place " .. name .. " at " .. minetest.pos_to_string(pos));
                minetest.set_node(pos, {name = "air"});
                return itemstack
            end
        end


        minetest.register_node(":"..name, table2)
        return;
    end


    return;
end


minetest.after(0,
function ()
prevent_place_above("bucket:bucket_water");
prevent_place_above("default:water_source");
prevent_place_above("bucket:bucket_lava");
prevent_place_above("default:lava_source");
prevent_place_above("es:toxic_water_source");
prevent_place_above("es:mud");
end
)



--TNT only below 150!

function no_tnt_above(name)

    local tnt_on_place=minetest.registered_craftitems[name];--.on_place;
    local tnt_after_place_node = minetest.registered_nodes[name];--.after_place_node;
    --after_place_node = func(pos, placer, itemstack, pointed_thing)

    if tnt_on_place and tnt_on_place.on_place then
        tnt_on_place=tnt_on_place.on_place;
        minetest.registered_craftitems[name].on_place=function(itemstack, placer, pointed_thing)
            local pos = pointed_thing.above
            if pos.y>-150 then
                minetest.log("action","ANTI GRIEF " .. placer:get_player_name() .. " tried to place " .. name .. " at " .. minetest.pos_to_string(pos));
                return itemstack
            else
                return tnt_on_place(itemstack, placer, pointed_thing)
            end
        end
    return;
    end

    if tnt_after_place_node then

        tntafter_place_node=tnt_after_place_node.after_place_node

        local table = minetest.registered_nodes[name];
        local table2 = {}
        for i,v in pairs(table) do
            table2[i] = v
        end

        table2.after_place_node=function(pos, placer, itemstack, pointed_thing)
            --after_place_node = func(pos, placer, itemstack, pointed_thing)
            local pos = pointed_thing.above
            if pos.y>-150 then
                minetest.log("action","ANTI GRIEF " .. placer:get_player_name() .. " tried to place " .. name .. " at " .. minetest.pos_to_string(pos));
                minetest.set_node(pos, {name = "air"});
                return itemstack
            end
        end


        minetest.register_node(":"..name, table2)
        return;
    end


    return;
end


minetest.after(0,
function ()
 no_tnt_above("tnt:tnt");

end
)

--lava
--bucket:bucket_water
--check and block player lava

minetest.register_globalstep(function(dtime)
    if minetest.is_singleplayer() == false then
        local range = 10
        for _,player in ipairs(minetest.get_connected_players()) do
            local player_pos = player:getpos()
            local pos = minetest.env:find_node_near(player_pos, range, "default:stone")
            --minetest.log("action","ANTI GRIEF " .. placer:get_player_name() .. " tried to place " .. name .. " at " .. minetest.pos_to_string(pos));
            while pos~= nil do
                minetest.env:add_node(pos,{name="default:lava_source"})
                pos = minetest.env:find_node_near(player_pos, range, "default:stone")
            end
        end
    end
end)