--[[
        ADJACENT STASH REWARDS (Tosox Mini Mods Repo)
        [https://www.moddb.com/mods/stalker-anomaly/addons/tosox-mini-mods-repo]

        This mod spawns rewarded stashes in the levels connected to
        your current level. So say bye to stash rewards in
        Pripyat while you are still exploring Cordon.

        Author: Singustromo <singustromo at disroot.org>
--]]

-- Superseded functions
GetRandomStash = treasure_manager.get_random_stash
BoxInSameMap = treasure_manager.box_in_same_map

--------------------------
--    Monkey Patches    --
--------------------------

-- We always force local stashes
function treasure_manager.get_random_stash(no_spot, hint, spawn_local, inv_box)
        -- Exception, so stash contents are created on first init
        -- It's called like this on first init in on_game_load():
        --   get_random_stash(true, "stash")
        local first_init = no_spot and (hint == "stash") and not (spawn_local and inv_box)

        spawn_local = not first_init -- Kinda scuffed but not compute intensive
        return GetRandomStash(no_spot, hint, spawn_local, inv_box)
end

-- Here we change the logic to find out which stashes are considered local
function treasure_manager.box_in_same_map(id)
        if (not id) then return end
	local obj1, obj2 = alife():actor(), alife_object(id)

	return is_on_nearby_level(obj1, obj2)
end

-----------------------------
--    Utility Functions    --
-----------------------------

function is_on_nearby_level(se_obj_1, se_obj_2)
        local obj1_level, obj2_level = get_obj_level(se_obj_1), get_obj_level(se_obj_2)
	if not (obj1_level and obj2_level) then return end
	
	return (obj1_level == obj2_level)
                or level_directly_connected(obj1_level, obj2_level)
end

function get_obj_level(se_obj)
        if (not se_obj) then return end

	local sim, gg = alife(), game_graph()
	return sim:level_name(gg:vertex(se_obj.m_game_vertex_id):level_id())
end

-- output of next() is nil when table is empty
function is_table_empty(tbl)
        return not (tbl and next(tbl))
end

-- Uses txr_routes.routes to determine if those levels are adjacent
-- Does not account for additional transitions made by e.g. Extra level Transitions
-- as that addon circumvents this vanilla system completely.
function level_directly_connected(section_1, section_2)
        local routes = txr_routes.routes
        local map1, map2 = txr_routes.get_map(section_1), txr_routes.get_map(section_2)
        if not (map1 and map2) then return end

        local route = (routes[map1]) and routes[map1][map2]
                or (routes[map2] and routes[map2][map1])

        return not is_table_empty(route)
end