require "defines"
local update_com_count = 80
local agro_area_rad = 40
local call_back_area_rad = agro_area_rad + 15
local max_unit_count = 20


game.on_init(function()
	if global.evolution == nil then
      global.evolution = {}
   end
end)

game.on_load(function()
   if global.evolution == nil then
      global.evolution = {}
   end
    for i = 1, #game.players, 1 do
        if game.players[i].force.technologies["Hive-mind"].researched then
           game.players[i].force.recipes["attractor-on2"].enabled = true
        end
    end
end)

game.on_event(defines.events.on_tick, function(event)
	if event.tick % update_com_count == 0 then
		for index, player in ipairs(game.players) do
			if player.character then
				UpdateUnitsCommands(index)
			end
		end
	end
end)

function UpdateUnitsCommands(player_index)
	local player = game.players[player_index].character
	local pos = player.position
    local aggression_area = {{pos.x - agro_area_rad, pos.y - agro_area_rad}, {pos.x + agro_area_rad, pos.y + agro_area_rad}}
	if not player.surface.valid then return end
	local targets = player.surface.find_entities(aggression_area)
	local min_dist = agro_area_rad + 10;
	local closest_index = -1
	local surface = player.surface

	for index, target in ipairs(targets) do
		if target.health then
			if target.force == game.forces.enemy and target.type ~= "turret" and target.type ~= "unit" then
				local dist = GetDistance(target.position, pos)
				if min_dist > dist then
					min_dist = dist
					closest_index = index
				end
			end
		end
	end

	local unit_count = 0
	if closest_index == -1 then

		local attOn = game.players[player_index].get_item_count("attractor-on")
		local attOff = game.players[player_index].get_item_count("attractor-off")
		local lastState = nil
		if global.evolution[game.players[player_index].name] and global.evolution[game.players[player_index].name].lastState then
			lastState = global.evolution[game.players[player_index].name].lastState
		else
			if global.evolution[game.players[player_index].name] == nil then
				global.evolution[game.players[player_index].name] = {}
			end
			global.evolution[game.players[player_index].name].lastState = nil
		end

		if attOn > 0 and attOff == 0 then
			if attOn > 1 then
				game.players[player_index].removeitem({name="attractor-on", count=(attOn - 1)})
			end
			lastState = "on"
		elseif attOn == 0 and attOff > 0 then
			if attOff > 1 then
				game.players[player_index].removeitem({name="attractor-off", count=(attOff - 1)})
			end
			lastState = "off"
		elseif attOn > 0 and attOff > 0 then
			if lastState ~= nil and lastState == "off" then
				game.players[player_index].removeitem({name="attractor-off", count=attOff})
				if attOn > 1 then
					game.players[player_index].removeitem({name="attractor-on", count=(attOn - 1)})
				end
				lastState = "on"
			else
				game.players[player_index].removeitem({name="attractor-on", count=attOn})
				if attOn > 1 then
					game.players[player_index].removeitem({name="attractor-on", count=(attOn - 1)})
				end
				lastState = "off"
			end
		else
			lastState = "off"
		end
		global.evolution[game.players[player_index].name].lastState = lastState

		if lastState == "off" then return end
		local call_back_area = {{pos.x -  call_back_area_rad, pos.y -  call_back_area_rad}, {pos.x +  call_back_area_rad, pos.y +  call_back_area_rad}}
		local biters = surface.find_entities_filtered{area = call_back_area, type = "unit"}
		for index, biter in ipairs(biters) do
			if biter.force == (player.force) then
				biter.set_command({type = defines.command.go_to_location, destination = pos, radius = 10, distraction = defines.distraction.byanything});
				unit_count = unit_count + 1

			end
			if unit_count > max_unit_count then return end
		end
	else
		local call_back_area = {{pos.x -  call_back_area_rad, pos.y -  call_back_area_rad}, {pos.x +  call_back_area_rad, pos.y +  call_back_area_rad}}
		local biters = player.surface.find_entities_filtered{area = call_back_area, type = "unit"}
		for index, biter in ipairs(biters) do
			if biter.force == player.force then
				biter.set_command({type = defines.command.attack, target = targets[closest_index], distraction = defines.distraction.byanything});
				unit_count = unit_count + 1
			end
			if unit_count > max_unit_count then return end
		end
	end
end

function GetDistance(pos1 , pos2)
	return math.sqrt((pos1.x - pos2.x)^2 + (pos1.y - pos2.y)^2)
end