local T = {}
T.Items =
{
--  {GivenItem, ReqItem1, ReqItem2, ... ReqItemN}
    {25, 35, 36},
    {25, 37, 38, 39},
    {25, 40},
    {25, 41},
}

T.Page = {}
T.Options = 20

function T.Count(Page)
    if(not Page or Page < 1) then
        return 1
    else
        return (Page*T.Options)
    end
end

function T.Max(Count, LData)
    if(LData - Count >= T.Options) then
        return Count+T.Options-1, true
    else
        return LData, false
    end
end

function T.Hello(pUnit, event, pPlayer)
    local str = tostring(pPlayer)
    if(not T.Page[str] or T.Page[str] < 0) then
        T.Page[str] = 0
    end
    local Page = T.Page[str]
    local Count = T.Count(Page)
    local Max, Next = T.Max(Count, #T.Items)
    pUnit:GossipCreateMenu(1000, pPlayer, 0)
    -- for k, v in ipairs(T.Items) do
    for k = 1, #T.Items do
        local Add = true
        for i = 2, #T.Items[k] do
            if(not pPlayer:HasItem(T.Items[k][i])) then
                Add = false
            end
        end
        if(Add) then
            local Name = WorldDBQuery("SELECT Name1 FROM items WHERE entry = "..T.Items[k][1]):GetColumn(0):GetString()
            pUnit:GossipMenuAddItem(0, Name, k, 0)
        end
    end
    if(Next) then
        pUnit:GossipMenuAddItem(7, "Next page", 490, 0, '', 0)
    end
    if(Page > 0) then
        pUnit:GossipMenuAddItem(7, "Previous page", 491, 0, '', 0)
    end
    pUnit:GossipSendMenu(pPlayer)
end

function T.Select(pUnit, event, pPlayer, id, intid, code)
    if(T.Items[intid]) then
        if(pPlayer:AddItem(T.Items[intid][1], 1)) then
            for i = 2, #T.Items[intid] do
                pPlayer:RemoveItem(T.Items[intid][i], 1)
            end
        else
            pPlayer:SendAreaTriggerMessage("Your inventory is full")
        end
    end
    T.Hello(pUnit, event, pPlayer)
end

local ID = 6948 -- NPC entry
RegisterUnitGossipEvent(ID, 1, T.Hello)
RegisterUnitGossipEvent(ID, 2, T.Select)

-- RegisterItemGossipEvent(ID, 1, T.Hello)
-- RegisterItemGossipEvent(ID, 2, T.Select)