--	picks a random squad from "squad_descr_day_stalkers.ltx" every "spawn_time_interval" game minutes
--	spawns on smart terrains available for stalkers and if current population of smart is 0 or if no default day stalkers are on this smart online
--	ALL CREDIT GOES TO bvcx/xcvb

local spawn_time_interval = 5	-- game minutes
local safe_radius = 60					-- no spawn in this player's radius

local night_start = 6            			-- time at which stalkers start to spawn
local night_end = 19     				-- deletes all stalkers at this time !!!Skipping this time by sleeping will not delete stalkers!!!

local squads_to_spawn = {}
local spawned_stalkers = {}
local available_smart_terrains = {}
local ctime_to_t = utils_data.CTime_to_table
local t_to_ctime = utils_data.CTime_from_table
local xspawn_time
local debugx = false

---------------------------------------------------------------------------------------------------
local tmr
function try_to_spawn()
	local tg = time_global()
	if (tmr and tg < tmr) then return end
	tmr = tg + 30000

	if not is_night() then
		if is_not_empty(spawned_stalkers) then
			delete_mutants()
			empty_table(spawned_stalkers)
			xspawn_time = nil
		end
		return
	end

	local cur_time = game.get_game_time()
	if not xspawn_time then
		xspawn_time = ctime_to_t(cur_time)
	end

	if cur_time:diffSec(t_to_ctime(xspawn_time)) > (spawn_time_interval * 60) then
		xspawn_time = ctime_to_t(cur_time)
		spawn_mutants()
	end

end

function spawn_mutants()
	for level_name, t in pairs(available_smart_terrains) do
		local random_smart_id = t[math.random(1, #t)]
		spawned_stalkers[level_name] = spawned_stalkers[level_name] or {}

		local simboard_t = SIMBOARD.smarts[random_smart_id]
		local smart = simboard_t and simboard_t.smrt

		if smart then
			local smart_squads = simboard_t.squads
			local smart_cur_pop = simboard_t.population
			local smart_max_pop = smart.max_population

		-- smart is empty
			local allow_pop_spawn = smart_cur_pop < smart_max_pop

			pr("----------------------------------------------------")
			local smart_name = smart:name() or smart:section_name() or "<empty>"
			pr("1test smart_id: %s || smart_name: %s || max pop: %s || current pop: %s", random_smart_id, smart_name, smart_max_pop, smart_cur_pop)

		-- if at least one night squad is already on this smart
			local night_squad_on_smart = false
			for squad_id, _ in pairs(smart_squads) do
				local sq = alife_object(squad_id)
				if sq and (sq.player_id == "monster_predatory_night" or sq.player_id == "monster_zombied_night") then
					pr("squad_id is NIGHT squad: %s", squad_id)
					night_squad_on_smart = true
					break
				end
			end

			-- spawn squad
			if allow_pop_spawn and (not night_squad_on_smart) and se_obj_outside_spawn_radius(smart) then
				local squad_sec = is_not_empty(squads_to_spawn) and squads_to_spawn[math.random(1, #squads_to_spawn)]
				local squad = squad_sec and SIMBOARD:create_squad(smart, squad_sec)
				-- save squad id
				if squad then
					table.insert(spawned_stalkers[level_name], squad.id)
					-- test
					pr("- spawned level: %s || smart: %s || squad_id: %s || sec: %s", level_name, smart_name, squad.id, squad_sec)
					pr("2test smart_id: %s || current pop: %s", random_smart_id, SIMBOARD.smarts[random_smart_id] and SIMBOARD.smarts[random_smart_id].population)
					--------------
				end
			end

		end

	end

end

function delete_mutants()
	for level_name, t in pairs(spawned_stalkers) do
		for idx, squad_id in ipairs(t) do
			local squad = alife_object(squad_id)
			if squad then
				pr("squad id: %s deleted", squad_id)
				squad:remove_squad()
			end
		end
	end

end

function server_entity_on_unregister(obj)
	for level_name, t in pairs(spawned_stalkers) do
		for idx, squad_id in ipairs(t) do
			if obj.id == squad_id then
				pr("removing squad_id: %s from table", squad_id)
				table.remove(spawned_stalkers[level_name], idx)
			end
		end
	end

end

---------------------------------------------------------------------------------------------------
function save_mutant_smarts()
	-- save smarts that has props of  "sim_avail" = true and "stalker" > 0
	for i = 1, 65534 do
		local smart = alife_object(i)
		if smart and (smart:clsid() == clsid.smart_terrain) and (simulation_objects.available_by_id[smart.id] and simulation_objects.available_by_id[smart.id] == true) and (smart.props["stalker"] and smart.props["stalker"] > 0) then
			local smart_level_name = get_se_obj_level_name(smart)
			available_smart_terrains[smart_level_name] = available_smart_terrains[smart_level_name] or {}
			table.insert(available_smart_terrains[smart_level_name], smart.id)
		end
	end

	-- collect and add section names
	ini_sys:section_for_each(function(sec)
		local night_mutant = ini_sys:r_bool_ex(sec, "night_mutant")
		if night_mutant then
			table.insert(squads_to_spawn, sec)
		end
	end)

	-- test
	for i = 1, #squads_to_spawn do
		pr("[%s] = %s", i, squads_to_spawn[i])
	end

end

function se_obj_outside_spawn_radius(se_obj)
	if not se_obj then
		return false
	end

	local on_same_level = simulation_objects.is_on_the_same_level(alife():actor(), se_obj)
	if not on_same_level then
		return true
	end

	local ac_pos = db.actor:position()
	local se_obj_pos = se_obj.position
	local outside_radius = ac_pos:distance_to_xz(se_obj_pos) > safe_radius

	return outside_radius
end

function is_night()
	local cur_hour = level.get_time_hours() + level.get_time_minutes() / 60

	return (cur_hour > night_start) or (cur_hour < night_end)
end

function get_se_obj_level_name(se_obj)
	local target_level_id = game_graph():vertex(se_obj.m_game_vertex_id):level_id()
	local target_level_name = alife():level_name(target_level_id)

	return target_level_name
end

function pr(...)
	if not debugx then return end
	printf(...)
end

function save_state(m_data)
    m_data.spawned_stalkers = spawned_stalkers
	m_data.xspawn_time = xspawn_time
end

function load_state(m_data)
	xspawn_time = xspawn_time or nil
    spawned_stalkers = m_data.spawned_stalkers or {}
end

---------------------------------------------------------------------------------------------------
function on_game_start()
	RegisterScriptCallback("actor_on_update", try_to_spawn)
	RegisterScriptCallback("server_entity_on_unregister", server_entity_on_unregister)
	RegisterScriptCallback("actor_on_first_update", save_mutant_smarts)
	RegisterScriptCallback("save_state", save_state)
	RegisterScriptCallback("load_state", load_state)
end