local ammo_prefix = "ammo_"
local weapon_prefix = "wpn_"

local function npc_on_update(npc,st)
    if not (npc:alive()) then
        return
    end

    if(is_first_update_done(npc)) then
        return
    end

    remove_weapons_and_ammo(npc)

    give_weapon_and_ammo(npc)
    give_grenades(2, npc)

    utils.se_obj_save_var(npc:id(),npc:name(),"strelocc_de_first_update_done",true)
end

function give_weapon_and_ammo(npc)
    local w = get_weapon(npc)
    alife():create(w,npc:position(),npc:level_vertex_id(),npc:game_vertex_id(),npc:id())
    local a = get_ammo(w)
    alife():create(a,npc:position(),npc:level_vertex_id(),npc:game_vertex_id(),npc:id())
    --printf("given ammo %s for weapon %s",w,a)
end

function concat_2tables(table1, table2)
    local t3 = {}
    local len = table.getn(t3)
    for key, val in pairs(table1)do
        table.insert(t3,val)
    end
    for key, val in pairs(table2)do
        table.insert(t3,val)
    end
    return t3
end

function concatenateTables( tableList )
    if tableList==nil then
        return  nil
    elseif table.getn(tableList) == 1 then
        return  tableList[1]
    else
        local table1 = tableList[1]
        local restTableList = {unpack(tableList, 2)}
        return concat_2tables(table1, concatenateTables(restTableList))
    end
end


local ini = system_ini()
function get_ammo(weapon)
    --local class = system_ini():r_string_ex(weapon,"class")
    local ammo_class = alun_utils.parse_list(ini,weapon,"ammo_class")
    local ammo = ammo_class[math.random(1,#ammo_class)]
    return ammo
end

function give_grenades(n, npc)
    local i = 0
    while i<n do
        alife():create(get_nades(npc),npc:position(),npc:level_vertex_id(),npc:game_vertex_id(),npc:id())
        i = i+1
    end
end

local nine18_pistols = {"wpn_fort","wpn_fort_snag","wpn_pb","wpn_pb_sk1","wpn_pmm","wpn_tt33", "wpn_tt33_sk1"}
local nine18_pistols_auto = {"wpn_aps","wpn_oc33","wpn_oc33_sk1"}

local nine18_smg = {"wpn_bizon"}

local nine19_pistols_western = {"wpn_beretta", "wpn_beretta_sk1", "wpn_glock", "wpn_hpsa", "wpn_hpsa_sk1","wpn_walther"}
local nine19_pistols_slav = {"wpn_cz75","wpn_mp443", "wpn_gsh18", "wpn_gsh18_sk1"}

local fourty5_pistols = {"wpn_colt1911","wpn_colt1911_sk1","wpn_colt1911_sk2","wpn_colt1911_sk3","wpn_sig220","wpn_sig220_sk1","wpn_sig220_sk2","wpn_usp"}

--only high tier duty/freedom/monolith
local tacticool_pistols = {"wpn_fn57","wpn_fnp45","wpn_fnx45"}

--only high tier bandits
local fancy_pistols = {"wpn_desert_eagle"}

local sawn_shotguns = {"wpn_toz34_obrez","wpn_bm16"}
local hunting_shotguns = {"wpn_toz34","wpn_bm16_full"}
local low_shotguns = {"wpn_mp133","wpn_toz194"}
local mid_shotguns = {"wpn_mossberg590","wpn_remington870"}
local semiauto_shotguns = {"wpn_spas12", "wpn_mp153"}
local auto_shotgun = {"wpn_protecta","wpn_saiga","wpn_vepr","wpn_usas12"}

local rookie_w = concatenateTables({nine18_smg,hunting_shotguns,low_shotguns,nine18_pistols,nine19_pistols_slav,nine19_pistols_western})

function get_weapon(npc)

    --local community_list = { "stalker", "dolg", "freedom", "bandit", "army", "zombied", "ecolog", "killer", "monolith", "csky" }
    --character_community(npc) == "dolg"

    --novice, trainee,  experienced,  professional,  veteran,  expert,  master
    --local rank = ranks.get_obj_rank_name(npc)

    --game.get_game_time():diffSec(level.get_start_time())
    local pool = {}
    local faction = character_community(npc)
    local rank = ranks.get_obj_rank_name(npc)

    --army weapon pool
    if(faction == "army") then
        --if not a basic grunt has good non semiauto shotgun or bizon guaranteed
        if(rank~="novice" and rank~="trainee") then
            pool = concatenateTables({mid_shotguns,nine18_smg})
            return pool[math.random(#pool)]
        end

        --else only 9x18 and other slav pistols
        pool = concatenateTables({nine18_pistols,nine19_pistols_slav})
        return pool[math.random(#pool)]
    end

    --stalker and bandits have sawn off and hunting shotguns
    if(faction == "stalker" or faction =="bandit") then

        --only shitters can have sawn off
        if(rank=="novice") then
            pool = concatenateTables({sawn_shotguns,{}})
        end

        --pistols
        pool = concatenateTables({nine18_pistols,nine19_pistols_slav,nine19_pistols_western})
        --shotguns
        pool = concatenateTables({pool,hunting_shotguns,low_shotguns})

        return pool[math.random(#pool)]
    end

    --fallback pool to not have unarmed people
    return rookie_w[math.random(#rookie_w)]
end

function get_nades(npc)
    local faction = character_community(npc)
    local rank = ranks.get_obj_rank_name(npc)
    if(faction == "dolg" or faction == "army" or faction == "killer") then
        if(rank~="novice" and rank~="trainee") then
            return "grenade_f1"
        end
    end
    return "grenade_rgd5"
end

function is_first_update_done(npc)
    return utils.se_obj_load_var(npc:id(),npc:name(),"strelocc_de_first_update_done")
end

function remove_weapons_and_ammo(npc)
    local function itr(npc,itm)
        if(string.find(itm:name(), ammo_prefix)~=nil or string.find(itm:name(),weapon_prefix)~=nil) then
            local sim = alife()
            local se_obj = sim:object(itm:id())
            alife():release(alife():object(itm:id()), true)
        end
    end

    npc:iterate_inventory(itr,npc)
end

function on_game_start()
    RegisterScriptCallback("npc_on_update",npc_on_update)
end