minetest.register_privilege("trapsetter","Allow player to set traps")

local fsn = "spawnblock:configure"
local conflabel = "Set the trap"

local buildform = function(fields)
	formspeccer:clear("spawnblock:configure")
	formspeccer:newform("spawnblock:configure","10,9")
	for i=1,#fields do
		local def = fields[i]
		formspeccer:add_field(fsn,{name=def.name,label=def.label,value=def.value})
	end

	formspeccer:add_button(fsn,{name="submit",label=conflabel,xy="2,8",wh="5,1"},true)

	return fsn
end

buildform({
	{name="mobstring",label="Mob to spawn:",value=""},
	{name="playerradius",label="How close can player get before triggering",value=5},
	{name="spawnradius",label="Spawn radius",value=10},
	{name="maxobjects",label="Max number of things in spawn range",value=1},
})


minetest.register_node("spawnblock:cobble",{
	groups = {unbreakable = 1,},
	description = "Cobble spawn trap",
	tiles = {"default_cobble.png"},
	after_place_node = function(pos,player)
		local meta = minetest.get_meta(pos)
		meta:set_string("formspec",formspeccer:to_string(fsn))
	end,
	on_receive_fields = function(pos,formname,fields,player)
		--minetest.chat_send_all(dump(fields))
		if fields.submit ~= conflabel
		-- and not (fields.quit == "true" and fields.submit == nil)
		then 
			return
		end

		if not minetest.check_player_privs(player:get_player_name(), {trapsetter=true}) then
			minetest.chat_send_player(player:get_player_name(),"I cannot let you do that "..player:get_player_name())
			return
		end

		local meta = minetest.get_meta(pos)
		meta:set_string("mobstring",fields.mobstring)
		meta:set_int("maxobjects",tonumber(fields.maxobjects) )
		meta:set_int("playerradius",tonumber(fields.playerradius) )
		meta:set_int("spawnradius",tonumber(fields.spawnradius) )

		buildform({
			{name="mobstring",label="Mob to spawn:",value=fields.mobstring},
			{name="playerradius",label="How close can player get before triggering",value=fields.playerradius},
			{name="spawnradius",label="Spawn radius",value=fields.spawnradius},
			{name="maxobjects",label="Max number of things in spawn range",value=fields.maxobjects},
		})
		meta:set_string("formspec",formspeccer:to_string(fsn))
		
		minetest.chat_send_player(player:get_player_name(),"Trap set!")
	end,
})


local count_nearby_mobs = function(pos,radius)
	-- check if there are entities around already
	local objcount = 0
	for _,obj in pairs(minetest.get_objects_inside_radius(pos ,radius)) do
		if not obj:is_player() then
			objcount = objcount+1
		end
	end
	return objcount
end

local spawn_mob = function(pos,mobname,range)
	-- spawn a mob within spawnrange nodes of position pos
	local mobdef = minetest.registered_entities[mobname]
	if mobdef == nil then return end

	local spawninnode = {"air"}
	if mobdef.fly_in then spawninnode = {mobdef.fly_in} end

	local candidatenodes = minetest.find_nodes_in_area(
		{x = pos.x -range, y = pos.y+3, z = pos.z -range},
		{x = pos.x +range, y = pos.y+5, z = pos.z +range},
		spawninnode
	)
	local newpos = candidatenodes[ math.random(1,#candidatenodes) ]

	minetest.add_entity(newpos,mobname)
end

minetest.register_abm({
	nodenames = {"spawnblock:cobble"},
	neighbors = nil,
	interval = 1,
	chance = 1,
	action = function(pos)
		local fields = {}
		local meta = minetest.get_meta(pos)
		fields.mobstring = meta:get_string("mobstring")
		fields.playerradius = meta:get_int("playerradius")
		fields.spawnradius = meta:get_int("spawnradius")
		fields.maxobjects = meta:get_int("maxobjects")
		
		if fields.mobstring == nil or fields.mobstring == "" then return end

		for _,obj in pairs(minetest.get_objects_inside_radius(pos ,fields.playerradius)) do
			if obj:is_player() then
				if count_nearby_mobs(pos,math.ceil(fields.spawnradius)*1.4) < fields.maxobjects then
					if fields.mobstring ~= nil then
						local mobname = fields.mobstring
						local colonidx = mobname:find(':')
						if not colonidx then return end

						local mobnicename = mobname:sub(colonidx+1,#mobname )
						minetest.debug("Player "..obj:get_player_name().." triggered spawn trap at "..minetest.pos_to_string(pos))
						minetest.chat_send_player(obj:get_player_name(),"A wild "..mobnicename.." appeared!")
						spawn_mob(pos,mobname,fields.spawnradius)
					else
						minetest.debug("Failed to determine a mob for "..mobname)
					end
				else
				end
			end
		end
	end,
})