COOP_LEVELS = {
        "bk_coop_simulation_00",
        "coop_bb_deathstar_escape",
        "coop_meows_lockdown_v_2",
        "coop_mission_rehan_v3",
        "coop_ventilation",
        "js_coop_lj10_v2",
        "js_coop_module700_ttc_b3",
        "js_coop_p2_waterworks_ob",
        "level09_choose_your_destiny_a1",
        "lw_lambdaware_b4",
        "syn_deadsimple",
        "Poison_Coop_RE1_Beta1",
        "oc_systems2B-2",
        "oc_systems2B-1",
        "mph_twilight1_bb_fix",
        "level03_underground_1f5",
        "js_coop_sewers_vv5",
        "js_coop_minimall_p7",
        "js_coop_coast_x1",
        "coop_z_harrier2",
        "coop_d3_c17_10a_10b_jedi2e",
        "coop_bb_tombs_v1",
        "js_coop_tbr_[a1]_ttc_v6b",
        "js_coop_tbr_[a1]_ttc_v7a",
        "x_coop_kanny_lockdown_reloaded",
        "x_coop_minimall_reloaded_v5",
        "tbr_coop_skyscrapers_v4",
        "x_coop_space",
        "x_coop_helicave",
        "x_coop_citadel",
        "x_coop_minimall",
        "tbr_coop_thousand_antlions_v3b",
        "tbr_coop_red_keops_v4",
        "tbr_coop_red_keops_v2",
        "ta_coop_the_pitts_v2a",
        "ta_coop_the_edge_v4",
        "ta_coop_the_edge_v2",
        "ta_coop_run_for_your_life_v1",
        "ta_coop_run_for_your_life_0",
        "ta_coop_phrenetic_escape_v3",
        "ta_coop_phrenetic_escape_0",
        "ta_coop_last_man_standing_v5",
        "ta_coop_last_man_standing_v2",
        "ta_coop_last_man_standing_0",
        "syn_lvcoop_part2",
        "syn_lvcoop_part1",
        "sg_coop_steamlab_b5",
        "sg_coop_steamlab_b4",
        "sg_coop_steamlab_b1",
        "sg_coop_runoff_zb",
        "sg_coop_runoff_zb2",
        "sg_coop_resistance_b2",
        "sg_coop_resistance_b1",
        "sg_coop_overwatch_b4",
        "sg_coop_overwatch_b3",
        "sg_coop_overwatch_b1",
        "sg_coop_lockdown_b3",
        "scary_united_coop",
        "scary_gmod_coop_x",
        "poison_coop_re1_beta1",
        "oblivion_coop_v1",
        "mp_coop_fan_p2port",
        "mp_coop_fan_p2port_fawosfix",
        "mm_coop_underpass_v2",
        "js_x_coop_stargate",
        "js_lm_coop_underground_v4b",
        "js_coop_zero_g_oc4",
        "js_coop_waterworks_ttc_v4",
        "js_coop_waterworks_ttc_v3",
        "js_coop_vtol_x_v5",
        "js_coop_underground_x_v3",
        "js_coop_ultraviolet_v6b",
        "js_coop_ttc_tbr_p1",
        "js_coop_train_station_v1",
        "js_coop_train_reloaded",
        "js_coop_train_reloaded_2a",
        "js_coop_train_reloada",
        "js_coop_thunder",
        "js_coop_thunder_b4",
        "js_coop_thunder_b3a",
        "js_coop_thunder_b2",
        "js_coop_teleport_v9fix",
        "js_coop_teleport_sg_zb",
        "js_coop_teleport_sg_zb3",
        "js_coop_team_v3",
        "js_coop_team_ttc_b1",
        "js_coop_tbr_cave_v7a",
        "js_coop_tbr_cave_v5_!",
        "js_coop_subway_x_v6",
        "js_coop_subway_fixed",
        "js_coop_space_x_v2",
        "js_coop_space_station_v2a",
        "js_coop_space_fixed",
        "js_coop_sky_chase_tbr_v3",
        "js_coop_siege_v4",
        "js_coop_shore",
        "js_coop_sewers_v5",
        "js_coop_sewers_v3",
        "js_coop_savescientist_v5a",
        "js_coop_save_scientist_v4",
        "js_coop_save_scientist_v3b",
        "js_coop_savescientist_ob1",
        "js_coop_save_dog_v4b",
        "js_coop_save_dog_tbr_v5",
        "js_coop_save_dog_tbr_v3",
        "js_coop_rocks_v8",
        "js_coop_rm_powerworks_2020_v2",
        "js_coop_ravenholm_x_bb",
        "js_coop_ravenholm_x2",
        "js_coop_quest_vv9",
        "js_coop_quest_v9",
        "js_coop_quest",
        "js_coop_powerworks_v2",
        "js_coop_powercrysis_v3_b",
        "js_coop_part3_waterworks_v2",
        "js_coop_part2_waterworks_v3",
        "js_coop_part2_powerworks_v1a",
        "js_coop_nation_v1",
        "js_coop_monsterkill_v2b",
        "js_coop_monsterkill_reload_b",
        "js_coop_missiontwo_v1f",
        "js_coop_minimall_fixed",
        "js_coop_mesa_v3",
        "js_coop_lvls_tbr_combine_v1",
        "js_coop_lockdown_x_v7",
        "js_coop_lockdown_tbr_v3",
        "js_coop_lk8",
        "js_coop_lj9",
        "js_coop_lh5_windows",
        "js_coop_lh5",
        "js_coop_levels_tbr_rock_v27",
        "js_coop_levelcube_ttc_a",
        "js_coop_level8_x_v1",
        "js_coop_level5_x_v1",
        "js_coop_lc3_nuke_m",
        "js_coop_lc3",
        "js_coop_la4",
        "js_coop_killer_lost_v16",
        "js_coop_killer_lost_final_d1",
        "js_coop_horror_v13",
        "js_coop_horror_v12",
        "js_coop_helicave_x_v2",
        "js_coop_hanhack_vv6",
        "js_coop_hacktown_v3",
        "js_coop_hacktown_v1",
        "js_coop_gnarkill_puzzlev3",
        "js_coop_gethev_v1a",
        "js_coop_docks_x_v4",
        "js_coop_docks2_vv3",
        "js_coop_deep_v12",
        "js_coop_deep6_x_v4",
        "js_coop_dasole_x_v2",
        "js_coop_dasole_ttc_b1",
        "js_coop_dasole2_v7",
        "js_coop_dasole2_ttc_b1",
        "js_coop_cubix_v1",
        "js_coop_cranecase_x_v4",
        "js_coop_cranecase_p1",
        "js_coop_combine_reload_b",
        "js_coop_combine2_ttc_p5",
        "js_coop_combine2_sg_b4",
        "js_coop_combine2_sg_b3",
        "js_coop_coast_x_v5",
        "js_coop_citadel_v14fixx",
        "js_coop_citadel_blast_v5",
        "js_coop_church_ttc_ob",
        "js_coop_cavettc_ob",
        "js_coop_bugbait_v3",
        "js_coop_bridgewar_v6",
        "js_coop_blueberry_ob_p7",
        "js_coop_basemission_beta",
        "js_coop_antlionrun_v4",
        "js_coop_airboats_v5",
        "js_coop_acc_v6",
        "js_coop_2fort_teleport_p1",
        "js_coop_2fort_b11_teleport_x3",
        "js_coop_2011_savedog_v2",
        "jr_coop_undergroundescape_v1",
        "gm_escape_coop_part_01",
        "eye_coop8",
        "dm_rebledefence_coop",
        "dm_coop_perverslabyrinthe",
        "dm_chickencoop_v2",
        "csv_coop_evac_5_credits",
        "csv_coop_darkbonus",
        "coop_zombiescity",
        "coop_zombie_map",
        "coop_zombie_invasion_10_r1",
        "coop_zelda01_b",
        "coop_warpath_v1",
        "coop_war_of_the_worlds_1ve",
        "coop_wardogs_v5",
        "coop_wardogs_v4",
        "coop_venture_v1c",
        "coop_venture_rc4",
        "coop_uprising_c",
        "coop_unnormal",
        "coop_unnamed_1",
        "coop_underground_win",
        "coop_traps_v1c",
        "coop_trainstation_02_1cube",
        "coop_train_escape_z1",
        "coop_train_02_1cube",
        "coop_town_level4d",
        "coop_town_level3a",
        "coop_town_level2a",
        "coop_town_level1",
        "coop_tim-3",
        "coop_thunder",
        "coop_the_pitts_pr2",
        "coop_the_pitts_fix",
        "coop_the_escape_part4_beta4",
        "coop_the_escape_part3_beta5",
        "coop_the_escape_part2_beta6",
        "coop_the_escape_part1_beta19",
        "coop_the_edge_r1",
        "coop_swampthing_v6",
        "coop_striders_revenge_2b",
        "coop_stargate",
        "coop_sd_zombie-city_b1",
        "coop_run_for_your_life",
        "coop_run_for_your_life_0",
        "coop_rocks_v11",
        "coop_resistance_part1_v1c",
        "coop_resident_evil_sg_zb4",
        "coop_redqueen_zba_z3",
        "coop_rebel_incursion5",
        "coop_rebel_escape_r1",
        "coop_ravenholm_2a_cube",
        "coopqwest_one_jr",
        "coop_port_sg_zb",
        "coop_planet_ant",
        "coop_other_in_blackmesa_hl2",
        "coop_other_city17_outland_ep2",
        "coop_other_city17",
        "coop_other_city17_ep1",
        "coop_other_city17_antarctic_ep3",
        "coop_nvc_citadel_escape",
        "coop_npcwar_v6",
        "coop_npcwar_v6_aldo",
        "coop_npcwar_final",
        "coop_npcwar3_v6",
        "coop_npcwar3_final",
        "coop_npcwar3_aldo",
        "coop_npcwar2_final",
        "coop_npcwar2_aldo",
        "coop_mw_revenge_ttc_v1",
        "coop_monster",
        "coop_missile_silo_bb3",
        "coop_missile_silo206",
        "coop_miniflatgrass",
        "coop_militia_sg_zb",
        "coop_metamorphics_egypt_level1",
        "coop_meows_winter_wonderland",
        "coop_meows_tower_of_babel_v_4",
        "coop_meows_tower_of_babel_v_3",
        "coop_meows_symphony_eight_v_4",
        "coop_meows_stairway_hell_v_2",
        "coop_meows_stairway_hell_v_1",
        "coop_meows_sewer_mania_v_5",
        "coop_meows_sewer_mania_v4",
        "coop_meows_runoff_winter_v7",
        "coop_meows_runoff_winter_v5",
        "coop_meows_runoff_ver_1",
        "coop_meows_runoff_v_4",
        "coop_meows_runoff_v_3",
        "coop_meows_runoff_v_2",
        "coop_meows_round_robin_v9",
        "coop_meows_round_robin_fixed",
        "coop_meows_revenge_v_3",
        "coop_meows_pyramid_v1",
        "coop_meows_pyramid_pr1",
        "coop_meows_pitifull",
        "coop_meows_new_tricks_v_7a",
        "coop_meows_new_tricks_v_6",
        "coop_meows_lockdown_v_3",
        "coop_meows_lockdown_v1d",
        "coop_meows_kill_em_all_ver2",
        "coop_meows_kill_em_all_v_4",
        "coop_meows_island_defence_v_1",
        "coop_meows_island_defence",
        "coop_meows_icey_topsy_turvey",
        "coop_meows_house_to_house_z1",
        "coop_meows_house_to_house",
        "coop_meows_house_to_house1",
        "coop_meows_fun_day_out_z1",
        "coop_meows_corridoors_v_6",
        "coop_meows_corridoors_v_5",
        "coop_meows_corridoors_r1",
        "coop_manticore",
        "coop_manticore_bb",
        "coop_lockdown_b2",
        "coop_linux_zombie_2b",
        "coop_linux_ravenholm_1g",
        "coop_level_9a",
        "coop_level_7b",
        "coop_level_6d",
        "coop_level_5b",
        "coop_level_4a",
        "coop_level_1",
        "coop_level_1b_cube",
        "coop_level07_scary_house_v4",
        "coop_level07_scary_house_fix2",
        "coop_level06_base",
        "coop_level02_traps_v1c",
        "coop_level01_dooms_entry_v1b",
        "coop_last_man_standing_v2",
        "coop_ktz-treehouse",
        "coop_ktz-hell",
        "coop_kinyoenta_vz_g",
        "coop_killbox_1",
        "coop_great_evil",
        "coop_fog_lab",
        "coop_fog_city",
        "coop_fleeravenholm_part1",
        "coop_fleeravenholm",
        "coop_fire_pit_finalv2",
        "coop_ffgs_powerhouse",
        "coop_evacuationbm",
        "coop_evac_5_credits",
        "coop_evac_4",
        "coop_evac_3",
        "coop_evac_2",
        "coop_evac_1",
        "coop_epicycle_v4",
        "coop_ep1_level4_remote_2b",
        "coop_ep1_level3_remote_2a",
        "coop_ep1_level3_remote_1e",
        "coop_ep1_level2_remote_1c",
        "coop_ep1_level2_jedi_1l",
        "coop_ep1_level1_remote_2a",
        "coop_dtm_c2e1_v1b209",
        "coop_dooms_entry_v1b",
        "coop_dogs_revenge_1b",
        "coop_dogs_rampage_2b",
        "coop_dog_1d_cube",
        "coop_defensegarage_v2",
        "coop_darkmesa",
        "coop_darkbonus",
        "coop_dark17",
        "coop_danmaku_i",
        "coop_d3_c17_15_d_2y",
        "coop_coopbox_v2",
        "coop_combat17",
        "coop_coast_01_1k_cube",
        "coop_city_c17_level3_jedi_1b",
        "coop_city_c17_level3_jedi_1a",
        "coop_city_17_level5_jedi_1b",
        "coop_city_17_level5_jedi_1a",
        "coop_city_17_level4_jedi_1h",
        "coop_city_17_level1_jedi_1a",
        "coop_city_17_jedi_2f",
        "coop_citadel_level1_2i",
        "coop_citadel_escape_v7",
        "coop_citadel_escape_v5",
        "coop_citadel_escape_v2fix",
        "coop_citadel_escape_p6",
        "coop_citadel_chapter12_1f",
        "coop_citadel_2_1a_cube",
        "coop_cc_nochance_v1b60",
        "coop_canalsv4",
        "coop_canalsv10",
        "coop_canals_f4",
        "coop_canals_f3",
        "coop_burlybrawl_bb",
        "coop_bunker_buddies",
        "coop_breen_1d_cube",
        "coop_breen_01_jedi_5e",
        "coop_blueberry_oblivion_x1",
        "coop_blueberry",
        "coop_blame!_log2_v2",
        "coop_blame!_log2_v1",
        "coop_blame!_log1_v2",
        "coop_blame_log1_v1",
        "coop_blame!_log1_v1",
        "coop_blame!_log1_v1a",
        "coop_blackmesa_combat",
        "coop_bb_xtotalcontrol",
        "coop_bb_xtotalcontrol_d",
        "coop_bb_level_2_b6",
        "coop_bb_level_1",
        "coop_atlantis_beta04",
        "coop_a_place_to_die_jbrfix_final_v1",
        "coop_a_place_to_die_jbrfixed2i",
        "coop_ant_tower_b1_3",
        "coop_across_the_darkness3a",
        "coop_abducted_4",
        "coop_abducted_3",
        "coop_abducted_2",
        "coop_abducted_1",
        "coop9_oblivion_blueberry_x3",
        "coop6_180_blueberry",
        "coop4_ob_gunzfly_p5",
        "coop4_ob_gunzfly_p4",
        "coop3_oblivion_lockdown_x1",
        "coop_123module_v2",
        "coop_123module_bb2",
        "cl_coop_venture_up",
        "cl_coop_quest_v5",
        "cl_coop_level3_topside_b2",
        "cl_coop_level2_survive_r1",
        "cl_coop_level2_survive",
        "cl_coop_level1_escape_r1",
        "cl_coop_level1_escape",
        "cl_coop_laserquest_b2",
        "cl_coop_doors_v4",
        "cl_coop_doors",
        "cl_coop_corridor_b3",
        "cl_coop_cages",
        "cl_coop_breakable",
        "cl_coop_breakable_b2",
        "ad_coop_mara_final"
}

function GetInstalledCoopLevels()
    local installedMaps = {}
    local availableLevels = {}

    for _, fileName in ipairs(file.Find("maps/*.bsp", "GAME")) do
        installedMaps[string.lower(string.StripExtension(fileName))] = true
    end

    for _, levelName in ipairs(COOP_LEVELS) do
        local normalizedName = string.lower(levelName)
        if installedMaps[normalizedName] and not table.HasValue(availableLevels, normalizedName) then
            table.insert(availableLevels, normalizedName)
        end
    end

    return availableLevels
end

function GetRandomLevel(excludeLevel)
    local candidates = {}
    local excluded = string.lower(excludeLevel or game.GetMap() or "")

    for _, levelName in ipairs(GetInstalledCoopLevels()) do
        if levelName ~= excluded then
            table.insert(candidates, levelName)
        end
    end

    if #candidates == 0 then return nil end
    return candidates[math.random(#candidates)]
end